Convert c code to java online free jobs

I'm aiming to elevate the online presence of my website through comprehensive search engine optimization. By focusing on boosting visibility, my primary goal is to attract and engage with the demographic of working professionals aged between 35 and 54. The efforts will be channeled solely into optimization for the Google platform. Ideally, I'm interested in working with freelancers who have extensive experience with Google algorithms and a proven track record of driving traffic to websites within this specific audience group. SEO expertise combined with an understanding of this demographic's online behaviour will be critical for success.

I'm looking for a freelancer who can convert a PDF document with less than 50 pages into a text document. Key Requirements: - The document has to be copied with exact formatting. - The content is in English. The ideal candidate should have experience with: - Copy typing - PDF conversion - Basic document formatting Note: Please make sure to detail any relevant experience you have in your bid.

I'm after a proficient image enhancing expert to convert a low resolution cell phone picture into a high-resolution image for printing. The final product should be optimized for a large format print (16x20 inches and above). The process should focus on smoothly blending the image details. It is therefore essential that you have: - Proven experience in image resizing and enhancing - Strong understanding of resolution requirements for large format printing - Proficiency in using state-of-the-art image manipulation software - Ability to deliver smooth and blended image aesthetics Your mission is to preserve as much detail as possible while providing a visually appealing output, fit for large format printing.

...proficient in MSIX packaging to convert a Windows exe installer into an MSIX package. I have exe of my software and want to convert it to MSIX, I tried using MSIX Packaging Tool. I could create MSIX package and even install it. The problem is that my exe has a windows service, MSIX Packaging Tool can detect it and can include in the package. But when I install the msix package for testing, I found that service is not being started (1053 error). When I compare service created by MSIX installer and exe installer there are some differences. I created MSIX package without VM machine. What you need to do? I will give you exe file for some other popular software, which already has same service which I need. You can create MSIX for that exe. If ...

...Project Brief: CADGIS to QGIS Conversion and Export to QField** **Project Overview:** We are seeking a skilled freelancer with expertise in Geographic Information Systems (GIS) to convert approximately 20 CADGIS maps into QGIS format. The successful completion of this project involves not only the conversion of these maps but also their subsequent export to QField for mobile GIS data collection and mapping. This project is pivotal for our field data collection efforts, allowing us to leverage precise and efficient GIS capabilities in our operations. **Objectives:** - Convert approximately 20 CADGIS maps into QGIS format with utmost accuracy. - Ensure that all elements of the CADGIS maps are properly transferred and functional within QGI...

I'm in need of a skilled individual who can efficiently convert a series of PDF documents to Word format. The key requirements and considerations for this project are: - **Primary Focus**: The main reason for this conversion is to allow for easy editing of the text in the Word file. Therefore, maintaining the integrity of the text layout, including font size, style and positioning, is crucial. - **Complex Layout**: The PDFs I need assistance with have a mixture of content, including text, images, and tables arranged in columns. - **Image & Table Handling**: It's important that the images and tables within the PDF are editable once converted to Word. So, the freelancer must have the capability to convert these elements in a way that ...

...- التطبيق يجب أن يكون متصلًا بالإنترنت. المهارات المطلوبة: - تطوير تطبيقات أندرويد - خبرة في التطور المتزامن لمنصات متعددة - قدرة على التواصل باللغة العربية - القدرة على العمل في بيئة متصلة بالإنترنت. المتقدمون للوظيفة يجب أن يظهروا أمثلة على العمل الذي قاموا به الذي يظهر مهاراتهم في التطوير لأندرويد والإتصال بالإنترنت. اعرض أمثلة على أعمالك السابقة الغات البرمجة: ثل Java، Kotlin لتطبيقات Android، و Swift، Objective-C لتطبيقات iOS.تطوير واجهة المستخدم (UI/UX): استخدام أدوات مثل Adobe XD، Sketch، أو Figma لتصميم وتطوير واجهة المستخدم.تطوير الواجهة الخلفية (Backend Development): معرفة بلغات البرمجة مثل Node.js، PHP، Python.استخدام أدوات التطوير: مثل Android Studio و Xcode لتطوير التطبيقات المحمولة.القدرة على التعامل مع قواعد البيانات: مثل MySQL، MongoDB، Firebase.مهارات...

I need a professional typist to quickly convert a set of PDF files into an Excel spreadsheet. Key Requirements: - Proficiency in data typing and MS Excel - Ability to handle PDF documents - Strong attention to detail and accuracy - Efficient work ethic to meet a tight deadline Please let me know if you're available to start immediately and can complete this task ASAP.

We are a growing web development company looking to expand our client base. We need an experienced Business Development Specialist to help us acquire new clients from scratch. If you have a proven track record in lead generation, client acquisition, and sales in the web development industry, we want to hear from you! Responsibilities: Develop and implement strategies to attract new clients for our web development services. Identify potential leads and convert them into clients. Build and maintain relationships with clients to ensure long-term partnerships. Conduct market research to identify new business opportunities. Create and deliver compelling presentations and proposals to prospective clients. Collaborate with our marketing te...

Hi Gaurav C., I noticed your profile and would like to offer you my project. We can discuss any details over chat.

I need a skilled translator to convert several mystery short stories from Russian to English. - The original stories are in Russian, and I am looking for a professional who excels in the nuances of the Russian language and can accurately convey the writing style of the texts in English. - An ideal candidate should be well-versed in translating fictions, in particular, to ensure that the suspense and intrigue of these stories are maintained. - The translated stories should be delivered individually per story. PLEASE NOT TO USE AI - I WILL FIND IT OUT ANYWAY

This requirement is to sell online training to IT Freshers and experienced professionals. Looking for tele callers who can convert the leads in to sales. Work from home Get paid as you sell Attractive incentives Rs. 500/- to 1000/- per sale Sale will on well developed website Valid leads will be given Weekly payments Whatsapp and report tracking Please do call us at - 9606807572 Note - This is " Get paid as you sell" model. No fixed, but attractive incentives for every sale. Thanks, Falcon Training Solutions , Bangalore.

I'm presently in need o...operational. The goal of this project is to set up Moodle for online tutoring. Your responsibilities would include overall Mood​le setup, configuration, testing, and handling any potential issues during and after the installation process. Ideal Skills and Experience: - Strong expertise in Moodle setup & configuration - Experience with Apache Servers and Linode Hosting - Troubleshooting and problem-solving skills - Knowledge of standard Moodle plugins (even though specific plugins were not selected for this project, understanding their functionality could be beneficial for potential future needs) Please ensure your proposal includes your previous experience with similar projects, your availability, and estimated project duration. Lo...

We seek a professional, seasoned RFID SME to help design/build an embedded RFID reader for UHF 860-960 MHz frequency range. It must be software defined and provide active digital support for it and peripherals. The output power, frequency & all other parameters should be software adjustable & saving of last data. Default factory settings set option. Applicable ISO standards like EPC global UHF RFID Class 1 Gen2/ISO 18000-63/6C. Full LLRP support. USA FCC Part 15 compliance is needed. ERP, EIRP power output compliance to international standards is needed. This may be always-on at times for wide area monitoring of RFID tags precise locations, per requirements given here. Should support OTA updates, embedded web server(testing, configuring & diagnostics). Remote dia...

...experienced developer to assist with migrating our website, which is built using Umbraco, C# coding, and MySQL database, to a new hosting environment. **Project Details:** - **Current Setup:** - Website developed in Umbraco (Microsoft open-source CMS). - Backend: C# coding. - Database: MySQL. - Currently hosted on a Windows server with IIS. - **New Hosting Environment:** - Hostinger VPS with Linux OS. - SQL Server installed via command line (no GUI). - No Windows server or IIS available. **Issues Encountered:** - Umbraco runs well locally on the VPS but not accessible externally. - Unable to attach the website domain. - Issues uploading the website from a local machine to the VPS. **Requirements:** - Expertise in Umbraco CMS. -...

I am seeking a talented freelance writer to craft and illustrate inspiring bedtime stories for children, which will be published on Amazon Kindle. This role involves utilizing advanced AI tools to create content that is both engaging and educational. The successful candidate will efficiently manage a structured creative workflow, supported by access to state-of-the-art tools. Responsibilities: - Story Development: Generate detailed story outlines using provided prompts. - Writing: Develop outlines into engaging stories using the given ChatGPT prompts, with the expectation to refine and fine-tune these prompts for optimal results. - Illustration: Create one AI illustration for each story using DALL-E, based on given or self-developed prompts. - Image Editing: Re...

I'm looking for a skilled software developer with proficiency in Java, Python, and C# to create a mobile application. The main goal of this project is to design and develop a mobile application with a seamless user interface and user-friendly experience. Key functionalities that the application should have include: - Efficient product catalog and search system to allow users to easily find and browse through available products - Intuitive user registration and login features to ensure a personalized experience for users The ideal candidate for this project should have a proven track record of developing mobile applications, with a strong understanding of Java, Python, and C#. Experience in e-commerce development and a k...

I'm in need of an expert 3D developer to create highly detailed product models, specifically for designing dentures from STL files. Key Project Details: - **Model Complexity**: The models should be intricate and highly detailed - **Texture and Lighting**: The models must be textured and well-lit to provide a realistic representation - **End Use**: The primary use of these models will be for designing dentures. Skills and Expertise Required: - Previous Experience: I'm looking for someone with a demonstrable portfolio of highly detailed product modeling work. - Proficiency in 3D Modeling Software: Expertise in software suitable for handling intricate, detailed models. - Understanding of Dental Industry: While not mandatory, prior experience or understanding of de...

I need a fluent, efficient typist to convert an English PDF into an doc -formatted Word document. Requirements: - The primary task is to convert the text from the PDF into a Word document. The original PDF is in English. - The Word document must be formatted in doc style. Familiarity with this style is a must. Pdf file must be typing and i need word .doc file . The PDF does not contain any tables but does include images. These images need to be included appropriately in the Word document. Ideal Skills: - Proficient typist - Strong understanding of APA formatting - Experience with incorporating images in Word documents Please provide a brief description of your relevant experience.

...and so on. We are conducting online recruitment for part-time researchers who are able to study on the newest trends of legislation in certain countries. We hope that your professional perspectives will be conductive to us and an abundant reward is assured. Responsibilities: This job requires our employees to- a) Share their professional knowledge; b) Deliver tasked articles or papers on time; c) Take advices from colleagues and embrace an open mindset to improve their work as required. Requirements: An applicant would be seen as potentially qualified if he/she- a) Has profound knowledge of the process of legislation in certain countries; b) Has previous working experiences in legal areas such as legislatures, law enforcement agencies, law fir...

I need a C# UWP application that compiles string as code using roslyn compiler. 1) should analyze code for errors and show error to user 2) take code from string variable, compile code and show output to user 3) sample code should include a while, if, variable assigment, arithematic, text output This is a template/skeleton/learning project. Must provide full documentation and details e.g. any project settings such as adding fulltrust capability, any limitations etc.

...in errors due to different configurations/libraries. SOLUTION Create a replica of EC2 production server (to be called "development") on AWS, that can be used for development and later for staging (once containerisation and CI/CD pipeline is configured) CONTRACTORS ANTICIPATED TASKS (high level): 1. Take backup of production instance on AWS. 2. Create new instance from the backup. 3. Configure and verify that code can pulled into the instance from bitbucket. 4. Setup required networking, database, monitoring, and Authorisation configurations. 5. Verify that the instance serves web application just like production and reflects any development updates. DELIVERABLES 1. Demo: a. Developer authenticates into the instance. b. Developer pulls new co...

I'm looking for an experienced Altium designer who can convert a set of PDF schematics into Altium Designer format. Our end goal is to have a fully annotated schematic with accurate component values and part numbers. Key requirements: - Conversion to Altium Designer 20+: I need the PDF schematics to be translated into Altium Designer 20 format. Familiarity with this specific version is crucial. - Full Annotation: It is important that all components are fully annotated with their corresponding values and part numbers. This is non-negotiable. - Use of Original Datasheets: I will provide all the necessary component datasheets for accurate reference. It is important that the final schematic reflects these datasheets accurately. Ideal skills and experience fo...

...looking for an animator who can bring my logo to life. The animation should depict a rabbit hopping out and peering from the logo. Then the hat should fall from the to and land on the letter C Here’s what I have in mind: - Duration: I'd prefer a quick and punchy animation, no more than 5 seconds long. - Emotion: The animation should evoke a playful and happy mood. - Creativity: I'm open to suggestions on how to make this logo animation unique and attractive. This project needs a professional with a strong grasp on creating and implementing 2D/3D animations. Experience with logo animation and an ability to capture essence of a brand will be a plus. Good communication is key as I value active update on the project's progr...

I'm in need of a professional to design and develop a customized banner website. It will need to be fully compatible for mobile browsing. Key Features: - Customization: The website should offer various customization options, with a live preview of the customized content. - PDF Export: The system should be able to convert the final design into a PDF format for printing. - Online Payment and Shipping: The site will need to integrate with Taiwan's Green World Technology payment gateway and logistics systems from Taiwan Post, 7-Eleven, and FamilyMart. - Admin Panel: A backend admin panel is required for managing customer orders. - Google Maps Integration: The website should be linked to Google Maps. - Image Slider: The site should ha...

...this.... and get paid to do so. The free software can be found here: It's easy to install in Windows, Linux, or macOS. I also have it installed on one of my machines, but my internet connection is currently limited with my cell phone hotspot, so I am willing to pay you to allow your machine to stay online and run as a peer. I want to contribute to the decentralized search network and also connect as a peer to your machine. This can be done in the background. You could continue using your computer for other tasks. Key Requirements: - Able to download the free software and install it on your machine - Keep your machine online (or most of the time) - You may have to configure you...

I'm looking for a proficient Android developer skilled in Java or Kotlin who can revamp an existing Bangladesh-focused app into a helpful productivity tool. Key requirements include: - Shifting the app's core functionality from its current state to serving as a productivity tool. - Leveraging the current feature set to increase efficiency and user experience. - Offering fresh, creative suggestions for enhancing app usage. Since the specific productivity function and additional features weren't specified, an open-minded approach is required to explore and determine the most impactful features during the development process. Your proposal should include your skills and relevant experience, as well as some initial ideas on how you would transfo...

My website's primary goal is to sell motel room accommodations. I aim to offer a seamless and user-friendly space for users to learn about my offerings and book them hassle-free. For this project, I need a professional with: - Experience in web development (1-5 pages) - Proficiency in creating visually engaging and intuitive UI/UX designs - Proven SEO skills to boost website visibility - Experience in the lodging/ hospitality industry is a major plus You'll be enhancing my online presence and ensure our motel facilities are the first choice for potential bookers.

**NO OR LIMITED EXPERIENCE IS OK - FEEL FREE TO APPLY. DO NOT USE GENERIC BID TEXT (NO COPY PASTING)*** Role is perfect for motivated and learning individuals who are eager for feedback and want to grow skills. Duration is 30 days internship. Those who surpass expectations will receive a serious offer to stay on team with better compensation. Sample tasks and responsibilities include, and are NOT limited to: 1. Research key topics or areas of interest and presenting options for the next steps. -> googling 2. Executing next steps and promptly executing action items from discussions. -> take instructions and act fast 3. Propose options from research as requested -> more googling 4. Be able to advise proactively on details including ...

Job Title: I am looking for a expert mobile app developer Job Description: Looking to get some quotes on creating an app for me. Ideal candidates for this project should have experience in developing user-friendly mobile applications, particularly for information sharing purposes. Strong skills in UX/UI design will be a big plus. Strong problem-solving skills, attention to detail, and the ability to work independently are essential. Skills:Mobile App Development, iPhone, Android, Objective C, iPad, Flutter, Cocoa, Kotlin, App Developer

...need of a creative designer to help me put together a striking End of Financial Year flyer. The main aim of this flyer is to promote special discounts. Key requirements and expectations: - The flyer should be designed for digital distribution, in PDF and JPEG formats. - It should have a perfect blend of specific product images and generic thematic visuals to create an engaging and appealing design. Ideal Skills: - Proficiency in graphic design - Experience in creating engaging and effective promotional materials - Ability to balance product imagery with thematic, brand-appropriate visuals Your task will be to create a design that not only catches the eye but also effectively communicates our end of financial year discounts to our custom...

I'm looking for an experienced ...looking for an experienced Automotive Engineer who can convert the entire transmission system of my Toyota Corolla, a hatchback car, from automatic to manual. Key Requirements: - Expertise in Auto to Manual Transmission Conversion. - Specific experience with Toyota Corolla models preferred. - Ability to explain the process and provide consultation. Your primary responsibility will be to completely convert the current automatic transmission system to a manual one. I seek a highly skilled and reliable professional who guarantees a smooth and efficient transition. This conversion should result in an optimized performance and enhanced driving experience. Please detail your experience with similar proje...

Please Sign Up or Login to see details.

I'm on the lookout for a competent, experienced individual to build my website on the Kajabi education platform. The project includes the following key aspects: Key Components: - Designing and developing a Home Page - Creating Course Pages - Setting up a Members Area Desired User Interaction: - Ability for users to leave comments on courses The ideal candidate should have proven experience in developing Kajabi websites, online educational platforms, and incorporating user interaction features. Understanding of user experience principles and attention to detail is pivotal.

...proficient Java coder who can design and implement a code that will graphically visualize the Critical Path Method (CPM) and Program Evaluation and Review Technique (PERT) networks in project management. Requested to implement a program in Java programming language and graphically visualize the network/graph generated as a result of executing the Critical Path Method (CPM) and Program Evaluation and Review Technique (PERT) in Project Management. Key functionalities include: - Generating CPM network - Generating PERT network - Graphically visualizing CPM network - Graphically visualizing PERT network The code should be designed to take input of project tasks, duration and their dependencies, creating a detailed and clear diagrammatic networ...

...UI/UX designer to create a professional landing page for my product/service. The primary goal of this landing page is to attract leads, and ultimately, convert them into customers. The design should be visually appealing, modern, and user-friendly, to encourage visitors to engage with the page. Key Requirements: - Design of a landing page in Figma that effectively advertises my product/service - Inclusion of high-quality product images, to showcase the offering - Integration of a user-friendly, easily accessible contact form The ideal candidate for this project will have a strong background in UI/UX design, with a keen eye for detail and a proven track record in creating successful landing pages. Experience with Figma is a must, as well as a ...

We would like you to create an 8.5x11 inch (portrait orientation) print advertising page according to the following details. Elements required in image: • The Origins Logo in black. • Either or both dice images (one large) (remove white background). • The Text list below. • A predominantly orange background (you can embellish as you like), with purple accents. • Our tower logo. • Our text logo. • Optional: Line art dice as background embellishments, or additional design elements. Text required: • The official Collector’s Edition Dice of Origins 2024! (near the top) • Only at Booth #1201 (Large) • Plus, find our coupon in the coupon book! (near the bottom) • Made in our Aether Dice style, these 4-color dice featu...

I'm in need of a freelancer who can help me parse my VCF file and convert it to a different format. The main goal of this task is to extract the genotype information from the file. input will be VCF file (from ONT whole genome run) and csv file with columns containing rsID, chromosome number, position. output will be same as input csv file, with extra column showing genotype from VCF at the given position can run on Mac shell so either perl or python would be fine. Ideal Skills & Experience: - Proficient in parsing VCF files and understanding genotype data - Experience in converting files to various formats like CSV, TXT, and XLS - Attention to detail to ensure accurate extraction of the data - Knowledge of any data validation methods wou...

Hi Wilmer C., I noticed your profile and would like to offer you my project. We can discuss any details over chat.

...management needs. Here’s a high-level outline of how you can set up each of these functions: 1. IT Assessment Portal This portal can be designed to allow technicians to enter and view data regarding client servers, PCs, and other equipment when on-site. Features to Include: • Client Details: Ability to enter and retrieve information about the client, like name, location, contact details. • Equipment Checklist: A dynamic checklist for different types of equipment (servers, PCs, etc.) that technicians can fill out. • Assessment Forms: Forms for entering the condition and performance of each piece of equipment. • Photo Uploads: Capability to upload photos directly from the site. • Reporting: Generate reports based o...

Project Description: We're developing "Climate Companion," an innovative mobile app designed to empower individuals and communities to take meaningful action on climate change. The initial focus will be on building the Android version of the app, with future expansion to iOS. This app will leverage Google's Gemini AI to provide personalized climate insights, actionable recommendations, and foster community engagement. We're looking for an Android developer with expertise in: Android SDK: Proficiency in building Android apps using Java/Kotlin and the Android SDK. API Integration: Experience integrating with RESTful APIs, specifically the Gemini API, and handling JSON data.

...a sales expert that can generate leads and sell an online course on money-making strategies. The course is designed for 18-35 year olds aspiring to achieve financial independence. Key Responsibilities: - Develop a comprehensive sales strategy to effectively market the online course - Utilize your expertise to reach and engage with the target audience - Maximize sales Ideal Skills: - Proven track record in sales, preferably in the online course industry - Familiarity with the target audience and their online behavior - Strong communication and persuasion skills - Understanding of online marketing tools and techniques - Ability to work independently You will be provided with personal discount codes, so that you can persua...

I am excited about the opportunity to assist you in planning an engaging 1-2 week leisure travel experience. With my extensive background in travel planning and a deep passion for exploring diverse destinations, I am confident in my ability to create a well-rounded itinerary that blends relaxation and exploration. Key Proposal Elements: 1. Customized Itinerary: • A detailed, day-by-day itinerary designed to maximize your travel experience. This will include a mix of relaxation and adventure, tailored to your preferences. 2. Destination Research and Analysis: • Comprehensive research on potential destinations, evaluating factors such as cost, tourist density, safety, and unique attractions. My goal is to recommend places that offer a perfec...

I'm seeking a Webflow expert who can help me convert a Figma design into a fully functional website. Key Requirements: - Implementing Contact Forms and Subscriptions: The website should have user-friendly contact forms and a subscription feature that allows users to sign up for newsletters or updates. - User Account Management: The website will also require a user account management system. Registered users should be able to access certain features and content that non-registered users cannot. - Social Media Integration: The website needs to be integrated with social media platforms. This includes features like sharing content, following the brand on social media, and potentially even logging in with social media credentials. Your Experience: - Proficien...

...web development team specialising in ReactJS? We are looking for a skilled team to bring our online marketplace to life. Our Figma designs and backend are ready to go; we need your expertise to convert these designs into a fully functional, high-performance website. Project Scope: Frontend Development: Build the frontend of our online marketplace using ReactJS, ensuring seamless integration of our Figma designs. API Integration: Implement APIs to connect the frontend with our backend, enabling all functionalities of the website. Chat Feature: Integrate Sendbird SDK/API to provide robust chat functionalities within the marketplace. Clean Code Practices: Adhere to industry-standard clean code practi...

I need to find someone to fix a wordpress website error containing 5000 articles and 404 products, suspected of being infected with malicious code due to containing many strange files. The admin page can still access the article product pages, but there is a 404 error

Looking to collaborate with Antenna experts for design/build of RFID UHF 860-960 MHz Active Digital always on antenna. It will support any RFID tags of the stated frequency range and the protocol. We have identified some possible technologies below but will rely on your expertise to pick one or combination of these or another suitable one from your experience. If you know of a pre-built solution that will be ideal. This antenna will be connected to our MCU via a comm port and be fully software defined. Our objective is to accomplish a 0.3 meters x,y,z 3D planer precision location of RFID UHF passive tags at about 25 meter cone at about 8 meters height from floor. Must be RFID UHF Frequency range (roughly 860-960 MHz, supporting US, Europe, Asia spectrums) App...

...Dafny developer to support me in the completion of existing code. I need him to pass verification of the code by the instructions exactly. it requires knowledge in proofs, using lemmas. Key Responsibilities: - Complete existing code in Dafny - Conduct code verification and ensure it passes successfully - Ensure the code is coherent and properly structured Requirements: - Proficient in Dafny - Extensive experience with complex algorithms and data structures - Able to work with well-documented code and project requirements - Strong problem-solving skills - Excellent communication skills, as we will need to discuss certain parts of the code Prior experience with similar projects and a good track record of succ...

I'm in need of a savvy digital marketer who can help me generate more leads for my business. - The goal is to significantly increase the number of leads my business receives. - You should be able to leverage social media and other digital marketing techniques to fulfill this objective. - The target audience is a mix of B2B and B2C, so experience in both sectors would be beneficial. - Proficiency in Facebook, Instagram, and LinkedIn is preferred. - The ideal candidate will have a strong track record in lead generation and a good understanding of digital marketing strategies that convert. If you're confident in your lead generation skills and can deliver tangible results, please place your bid.

I'm in need of a Spring application that offers a multi-authentication system to allow users to log in using Oauth2, DB username/password, and LDAP, all integrated into a single application. Ideal Skills: - Proficiency in Java and Spring Framework - Experience with Oauth2, LDAP, and database management - Strong understanding of security practices and multi-authentication configurations I would require the following features: - Seamless integration of Oauth2, DB username/password, and LDAP for user authentication