Convert desktop application web net工作

筛选

我最近的搜索
筛选项:
预算
类型
技能
语言
    工作状态
    2,000 convert desktop application web net 份搜到的工作,货币单位为 USD
    分析数据 已经结束 left

    数据库优化,数据分析,.net相关系统的模块的开发。数据库的相关开发

    $244 (Avg Bid)
    $244 平均报价
    1 个竞标

    软件编程,系统开发,技术熟练,开发进度快。为您解决问题,细致认真。

    $794 (Avg Bid)
    $794 平均报价
    2 个竞标

    做一个静态网站。可以用。net,php或者dedecms框架写。

    $273 (Avg Bid)
    $273 平均报价
    4 个竞标

    我们需要写一个iOS的app,专门用于复习语文考试的第一题字音题。我们会提供3000个词和其汉语拼音(unicode txt文件)。 第一版只需要实现两个功能,第一个是字音的显示,第二个字音的输入(当然还包括数据的搜集)。 如果第一版合作成功,我们会继续合作。 合格的申请人应该要应该提交一份项目计划书,大致说明需要的时间。此外,请提交一份程序代码的样品。

    $2132 (Avg Bid)
    $2132 平均报价
    6 个竞标

    我们需要写一个iOS的app,专门用于复习语文考试的第一题字音题。我们会提供3000个词和其汉语拼音(unicode txt文件)。 第一版只需要实现两个功能,第一个是字音的显示,第二个字音的输入(当然还包括数据的搜集)。 如果第一版合作成功,我们会继续合作。 合格的申请人应该要应该提交一份项目计划书,大致说明需要的时间。此外,请提交一份程序代码的样品。

    $527 (Avg Bid)
    $527 平均报价
    4 个竞标

    Hhhhgghhhhhhhhhhddrtgfffgjfrghhfdvggb

    $10 - $30
    $10 - $30
    0 个竞标

    Hhhhgghhhhhhhhhhddrtgfffgjfrghhfdvggb

    $10 - $30
    $10 - $30
    0 个竞标

    家e通 好友街 家e通 好友街 家e通 好友街 家e通 好友街 家e通 好友街

    $700 (Avg Bid)
    $700 平均报价
    6 个竞标

    和誠企業.成立於1995年泉州市雙陽工業區,台商入資1200萬/美金,經過進歷年的茁壯成長及國際市場穩定的流動資金量及市場目前在職人員已超過1.8萬於人.MAIL:jia880126@

    $30 - $250
    $30 - $250
    0 个竞标

    SQL注入/代码审计/数据库权限/渗透测试技术 接渗透单子高手,联系电子邮箱:aqcp#(#改成@)语言要求:中文 熟练掌握各种内网渗透测试工具与相关知识,精通常见安全攻防技术:sql注入、xss、文件上传、文件包含、命令执行等漏洞 熟悉linux、unix、Windows、oracle、J2EE等各种环境下WEB的安全配置与安全检查及WEB漏洞防范; 熟悉各种脚本语言(asp,php,jsp,java,net、perl、python等)具备独立挖掘web安全漏洞与入侵手段 具备一定的网络安全知识,对网络安全结构、系统漏洞、入侵检测、病毒防护等有深入理论基础和实践经验; 熟悉渗透测试黑客攻防的步骤、方法、流程、熟练掌握各种渗透测试攻防工具有实际渗透经验者优先; 求大虾接单,脱裤,要求,电话,手机,姓名,邮箱,其他的一概不要。每笔单1000美金起步,根据站的难度而定价格,具体可以详谈,寻找长期合作. 态度认真、中介勿扰,请技术实力说话。

    $2249 (Avg Bid)
    $2249 平均报价
    4 个竞标

    我们想做一个app.大概的功能如下 1.这是一个好友间的3d交互程序.需要获取本地联系人列表/qq好友/微信好友/或是facebook好友 2.可以把不同好友的照片贴到3d人物模形的面部. 3.可以对此3d人物模拟进行一些动作(打击/摇动).从而产生一些数据. 4.可以将此数据发送给目标用户.目标用户可以查看对方对他做了什么动作 5.会有一个排行榜. 6.对3d人物模型打击的时候,可以使用道具 (需要接入道具商店) 7.道具商店接入app支付系统(ios/android) 8.可以对3d人物模型做一些简单的自定义(头发.帽子....) 服务端,好友数据.app数据,美术,后台由我们这边的程序负责

    $5971 (Avg Bid)
    $5971 平均报价
    2 个竞标
    a mobile application 已经结束 left

    我们想做一个app.大概的功能如下 1.这是一个好友间的3d交互程序.需要获取本地联系人列表/qq好友/微信好友/或是facebook好友 2.可以把不同好友的照片贴到3d人物模形的面部. 3.可以对此3d人物模拟进行一些动作(打击/摇动).从而产生一些数据. 4.可以将此数据发送给目标用户.目标用户可以查看对方对他做了什么动作 5.会有一个排行榜. 6.对3d人物模型打击的时候,可以使用道具 (需要接入道具商店) 7.道具商店接入app支付系统(ios/android) 8.可以对3d人物模型做一些简单的自定义(头发.帽子....) 服务端,好友数据.app数据,美术,后台由我们这边的程序负责

    $5000 - $5000
    $5000 - $5000
    0 个竞标

    我有一个持续工作,之前与之相关的项目为'Convert excel data to APK file(run under android)'

    $15 - $15 / hr
    $15 - $15 / hr
    0 个竞标

    你好, 我们是一家纽约IT人才输送公司。 我们的员工在项目上需要一些技术支持, 主要是在oracle 数据库, .net方向上。我们可以签订长期合作计划。 有兴趣, 请给我们提供你们的电话联系方式。 我们的邮箱是info@。 电话 +1 609-759-1559。 谢谢! 祝好! Frank

    $150 (Avg Bid)
    $150 平均报价
    1 个竞标

    1.从09年就开始IPHONE的越狱应用和插件开发,积累了mobilesubstrate的插件的详细开发流程。 2.从10年开始imobiledevice的应用套件开发,截图,管理iphone,不在话下 3.从未停留过APP的开发,android,bada,blackberry,and so on...

    $15 - $25 / hr
    $15 - $25 / hr
    0 个竞标

    注册或者登录后来查看详情。

    加封 保密协议

    I'm seeking a diligent professional who can convert a PDF into a Word document for content editing purposes. Given the nature of the task, keen attention to detail is critical - I'm relying on you to maintain the document's current structure and format. Main Responsibilities: - Transfer all text from the PDF to a Word document. - Endeavor to preserve the original formatting wherever possible. - Facilitate simple content editing after the conversion. About You: - Proficient with Microsoft Word and Adobe Acrobat or similar software - Able to recognize the original format and implement it in Word - Strong attention to detail for maintaining structure and format integrity. Please note, further guidelines or specifications may be provided at a later date. However, not ...

    $18 / hr (Avg Bid)
    $18 / hr 平均报价
    27 个竞标
    PDF to Editable Word Typing 6 天 left
    已验证

    I need a freelancer to convert a simple text PDF file into an editable Word document. Key Responsibilities: - Convert PDF to Word, maintaining text format - Ensure the final output is fully editable Ideal Skills: - Proficiency in PDF to Word conversion - Knowledge of basic text formatting - Attention to detail and accuracy in typing The project is straightforward, requiring no additional formatting beyond converting the text. I'm looking for someone who can complete the task efficiently and accurately.

    $18 / hr (Avg Bid)
    $18 / hr 平均报价
    54 个竞标

    I need a freelancer to convert a simple text PDF file into an editable Word document. Key Responsibilities: - Convert PDF to Word, maintaining text format - Ensure the final output is fully editable.

    $17 / hr (Avg Bid)
    $17 / hr 平均报价
    36 个竞标
    PDF to Word Conversion Expert 6 天 left
    已验证

    I'm seeking a diligent professional who can convert a PDF into a Word document for content editing purposes. Given the nature of the task, keen attention to detail is critical - I'm relying on you to maintain the document's current structure and format. Main Responsibilities: - Transfer all text from the PDF to a Word document. - Endeavor to preserve the original formatting wherever possible. - Facilitate simple content editing after the conversion. About You: - Proficient with Microsoft Word and Adobe Acrobat or similar software - Able to recognize the original format and implement it in Word - Strong attention to detail for maintaining structure and format integrity. Please note, further guidelines or specifications may be provided at a later date. H...

    $104 / hr (Avg Bid)
    $104 / hr 平均报价
    5 个竞标
    Php Mobile App to Android APK 6 天 left
    已验证

    I have a mobile application's source code, written in PHP, that I need converted into an APK file with necessary settings. Key Requirements: - Convert PHP source code to an Android-compatible APK file - Implement necessary settings for the app to function properly on Android devices Ideal Freelancer: - Proficient in PHP and Android app development - Experienced in converting PHP applications to Android APKs - Has a good understanding of Android-specific settings and configurations

    $33 (Avg Bid)
    $33 平均报价
    7 个竞标

    I need a freelancer to convert a PDF file into a Word document while preserving its basic text formatting. Additionally, I would like the freelancer to create a table of contents in the Word document. The ideal candidate should be proficient in: - PDF to Word conversion - Basic text formatting in Word - Creating tables of contents in Word It is important that the freelancer maintains the integrity of the document's formatting during the conversion process.

    $10 / hr (Avg Bid)
    $10 / hr 平均报价
    67 个竞标

    I'm seeking a dedicated and skilled female sales agent to support my business. In this remote role, you'll be focused on lead generation within the retail sector. Key Responsibilities: - Lead generation: Your primary task will be to identify and develop leads within the retail industry. You'll need to proactively seek out potential business opportunities and convert them into qualified leads. Ideal Candidate: - Sales Experience: Prior experience in sales or lead generation, particularly in the retail sector, will be highly beneficial. - Communication Skills: You should possess excellent communication skills, particularly over the phone, as this role will involve cold calling. - Self-Motivation: Given the remote nature of this position, you should be self-driven and ...

    $14 / hr (Avg Bid)
    $14 / hr 平均报价
    8 个竞标

    I'm looking for a talented coder proficient in C# to develop a custom Volume indicator on the NinjaTrader platform. Key requirements and details: - Proficient in C#: You should have...proficient in C# to develop a custom Volume indicator on the NinjaTrader platform. Key requirements and details: - Proficient in C#: You should have a strong understanding of C# language. - NinjaTrader platform: Prior experience working with NinjaTrader is highly preferred. - Indicator type: The focus will be on creating a Volume indicator for the platform. Your role in this project will be to convert the volume indicator to the NinjaTrader platform using C#. If you have prior experience in similar indicator development and are comfortable with C# and the NinjaTrader platform, I would love to...

    $251 (Avg Bid)
    $251 平均报价
    15 个竞标

    ...in need of an advanced word processing application for desktop use on Windows and macOS. The application should have: - Spell check functionality to ensure accurate spelling - Grammar check feature to improve the overall quality of the document - Auto-correct feature to fix common typing errors The project does not require cloud storage capabilities. The key focus is on the word processing features listed above. Ideal freelancers for this project should have experience in: - Word processing software development - Proficiency in developing applications for Windows and macOS - Strong understanding of spell check, grammar check, and auto-correct features - Prior experience in developing similar applications A comprehensive and user-friendly application is a ...

    $11 / hr (Avg Bid)
    $11 / hr 平均报价
    14 个竞标

    Skilled Developer Needed to Convert WordPress Site to React Introduction: We are looking to transform our existing WordPress site, developed with Elementor and JavaScript, into a React-based platform to enhance user experience and functionality. Here’s the prototype for reference: Project Objectives: Enhance User Experience: The new platform should leverage React’s capabilities to deliver a seamless, modern, and engaging user interface. Dynamic Content Loading: Implement features beyond WordPress’s native capabilities, requiring custom functionality tailored to our content strategy. Design Fidelity: While converting to React, it's crucial to maintain the integrity of the original design and layout. Required Skills and Experience: React Expertise: Demonstr...

    $190 (Avg Bid)
    加精 加保
    $190
    0 项参赛作品

    I'm in need of a software tool that can convert PDF files to QIF, a type of financial transaction format. The tool should have the following features: - **Batch Conversion Capability:** The tool should be able to handle multiple PDF files at once, converting them into QIF format with ease. - **Automatic Categorization of Transactions:** I'd like the tool to automatically categorize transactions within the converted QIF files. This feature will save time and enhance the usability of the tool. Furthermore, the tool should adhere to specific formatting requirements for the converted QIF files, including: - **Date Format:** The converted QIF files should have the date format specified. - **Account Number Format:** The converted QIF files should have the account number forma...

    $11 (Avg Bid)
    $11 平均报价
    6 个竞标
    24D306 Solidworks Drafting 6 天 left
    已验证

    take existing PDF drawing, convert them to models, load analyse x 2 and add material if not strong enough, do a drawing set.

    $288 (Avg Bid)
    $288 平均报价
    17 个竞标

    Most Interesting and Challenging Work ------------------------------------------------ We need to create a webpage as document template builder so that user of the web application can design a template of certificate by dragging and dropping components and altering the styles in every aspect like - changing text style, background color and images, page size, water mark. That template will be saved and used for generating certificate of multiple person by changing data only. User don't know coding - everything should be user friendly to design the template. To provide more clarity and to set detail expectation - live demo will be shown. Developer should be very strong technical to build with quality and user friendly.

    $107 (Avg Bid)
    $107 平均报价
    11 个竞标

    I need two property scans that I took to be converted to Revit (one interior, and one exterior scan of the same residential property). I will need the overall dimensions added for the interior and exterior of the home. In additional to the as-built floorplan layout I will need a proposed floorplan. We are converting the a storage to a laundry room, and the existing laundry room to a bathroom. property address: 1868 Pamela Ln, Escondido, CA 92026 Interior scan link: Exterior scan link: I have additional photos and details upon agreement to work together. If we work together successfully I have a couple of these type of projects each month on average to give to you. Thank you for your time and consideration of this project, let me know if you have any questions

    $370 (Avg Bid)
    $370 平均报价
    21 个竞标

    We're looking for a solo front-end designer (not agency) who we can work with for an extended period of time. The last front-end person was with us for 3 years. The person needs to be really good at: Meeting deadlines and timelines. Created webpages that look exactly like the Figma designs provided. Pixel-perfect. There will be many projects we work on. For each project, I will let you know our budget prior to working on it.

    $152 (Avg Bid)
    $152 平均报价
    52 个竞标

    I'm in need of a professional and experienced C++ developer to convert my existing Matlab code to C++, with an advanced level of optimization. The primary goal of this conversion is to ensure that the C++ code runs seamlessly on a different platform.

    $30 - $250
    加封 保密协议
    $30 - $250
    6 个竞标

    I need an expert to cross-compile Qt 6.6 for Orange Pi Z3, suitable for a Linux environment. Some requirements include: - Determine and solve compatibility issues - Provide assistance in setting up the cross-compiling environment I prefer the installation process to be done immediately via remote desktop. WiringOP libraries should also be included. You should also document your transactions. Ideal candidates will have proficient Linux usage, Qt framework familiarity, experience with cross-compile tools setup, and worked with Orange Pi or similar alternatives.

    $142 (Avg Bid)
    $142 平均报价
    7 个竞标

    ...capable .NET developer to create a WebAPI using the Visual Studio template "WebApi Net core (Minimal api)". It needs to have Authentication and Authorization in place, using the X-API-Key. Key Requirements: - Authentication and Authorization: You need to enable X-API-Key based authentication and authorization for this WebAPI. - Data Model: The WebAPI will manage a simple 'City' table, performing basic CRUD operations. Expectations: - The X-API-Key should be hardcoded in the application. - The WebAPI should be developed using .NET 8.0 and the Visual Studio template "WebApi Net core (Minimal api)". - Data access should be implemented using EFCore. - Authorization should be handled through middleware. Ideal Skills and ...

    $30 (Avg Bid)
    $30 平均报价
    8 个竞标

    I'm in need of a developer who can convert my existing landing page to a thank you page. This is crucial, as it will allow me to effectively track conversions through Google Ads and Google Analytics. The key tasks and features for the job include: - Replicating the text content and images from the original landing page. - Incorporating a specific, pre-defined thank you message. - Ensuring that the look and layout of the thank you page mirrors that of the original landing page. The ideal candidate for this project should have: - Proficiency in web development, with previous experience in duplicating and repurposing landing pages. - A solid understanding of Google Ads and Google Analytics, to ensure that the tracking features are implemented correctly. - A good eye for d...

    $400 (Avg Bid)
    $400 平均报价
    79 个竞标

    I'm in need of a skilled designer to convert my current JPEG logo into a vector format. The vectorized logo will be utilized across both print and digital platforms. Your primary task is to ensure that the logo retains its original colors, so no color adjustments are required. Ideal Skills and Experience: - Proficiency in vector graphics tools - Experience with logo vectorization - Knowledge of both print and digital design requirements Please note that I'm particularly interested in working with a freelancer from South America. So, if you're based in this region or have experience with clients from South America, I'd be particularly keen to hear from you.

    $3 / hr (Avg Bid)
    $3 / hr 平均报价
    20 个竞标

    I am seeking an experienced .NET developer to build a highly dynamic REST API using the .NET 8 framework. The API will be designed to manage interactions with a database using a single, generic controller capable of handling all database tables. This project will involve implementing advanced features such as column selection, filtering, sorting, pagination, and complex table relationships like aggregations and master-detail references. Core Requirements: 1. API Framework: The API should be developed using .NET 8. I am open to using either OData or GraphQL for the API architecture, depending on what the developer finds most suitable for the project requirements. Alternative suggestions are welcome for discussion. 2. Generic Controller: The API should feature a single...

    $532 (Avg Bid)
    $532 平均报价
    53 个竞标

    I am working on finishing my basement as a spaceship themed theatre and need to convert my ideas into a model in SketchUp Process will be - I will provide an existing sketchup drawing with the shell of the room - I will provide inspirational Ai generated art showing what we want to achieve (but we will simplify it) - I will create videos of the space with what goes where and measurements so you can adapt it - Daily you will send the latest model and I'll suggest changes Desired Skills - interior design - audio and video equipment positioning

    $17 / hr (Avg Bid)
    $17 / hr 平均报价
    53 个竞标

    I'm looking for a Facebook Ads expert who can help me generate leads. Key Requirements: - Experience with lead generation campaigns on Facebook - Proficient in targeting older demographic (65+) with high net worth - Ability to focus on a specific local area I'm in need of someone who can craft ads that speak directly to high net worth adults in a specific local area. The primary goal is to generate leads, so it's crucial that the ads are not only engaging but also have a clear call to action that encourages these individuals to express interest in my services. It's very important that the freelancer has a deep understanding of Facebook Ads, including the platform's ad targeting capabilities. Previous experience with similar campaigns targeting a s...

    $160 (Avg Bid)
    $160 平均报价
    22 个竞标

    I'm looking for a professional who can convert a text PDF into a Word document. The main purpose of the conversion is to enable easy editing of the content. The Word document should be simplified in a way that makes it more user-friendly for future editing. Key Requirements: - Conversion of a text PDF to a Word document - Simplification of the Word document for easier editing Specific elements: - The conversion should include footnotes and endnotes from the original PDF. These are crucial for the content and need to be retained in the Word document. Ideal Skills and Experience: - Proficiency in PDF to Word conversion - Prior experience in simplifying documents for editing - Attention to detail to ensure all footnotes and endnotes are accurately included.

    $362 (Avg Bid)
    $362 平均报价
    97 个竞标
    Sales Funnel Design Overhaul 6 天 left
    已验证

    ...be beneficial. Ideal Skills and Experience: - Proven experience in designing and refreshing sales funnels, particularly with a focus on increasing conversion rates. - A solid understanding of the principles of user experience and how they can be applied in a sales funnel context. - A creative eye for design, able to suggest and implement changes that will engage users and encourage them to convert. Feel free to suggest other design elements that you think could be improved to help me achieve my conversion goals. THE FUNNEL IS BUILT IN HIGHLEVEL SO YOU NEED TO BE PROFICENT IN THE PLATFORM EXAMPLE FUNNEL EXISTING FUNNEL https://alignment

    $426 (Avg Bid)
    $426 平均报价
    70 个竞标

    ...Layout**: Aesthetically pleasing design that is in line with the branding of 3sigmacrm.com. The landing page should be visually engaging and easy to navigate, with a clear call-to-action. - **Responsive**: The landing page should be responsive and optimized for various devices, including desktop, tablet, and mobile. Ideal Freelancer: I'm looking for a skilled web designer with a solid portfolio of creating effective lead generation landing pages. The ideal candidate should have: - Experience in UI/UX design and web development - Proficiency in HTML, CSS, and Javascript, along with knowledge of responsive design - Ability to deliver quality work within a tight timeframe - Good communication skills and a proactive approach towards project updates and feedback. ...

    $15 (Avg Bid)
    $15 平均报价
    9 个竞标

    The purpose of this project is to write Visual Basic .NET code that interacts with the PayPal API to generate payments What I need: that will: - Obtain the access_token using OAuth2. - Create a payment. - Execute the payment. will: - Retrieve the response triggered by PayPal and process it accordingly by determining if the payment was successful or not. - If the payment wasn't successful, display a message saying that no payment was made. - If the payment was successful, display the details of the operation returned by PayPal. If you want to participate to this project please copy/paste this sentence in your bid "I have been working with PayPal API and I have got proficiency in Visual Basic .NET"

    $32 (Avg Bid)
    $32 平均报价
    10 个竞标

    Convert your images into stunning illustrations.

    $50 (Avg Bid)
    $50 平均报价
    1 个竞标

    Design and Implementation of an Application and Website Responsive User Interface (UI) Design: Ensure that the design functions smoothly and responsively on various devices such as desktop computers, tablets, and smartphones. Content Management System (CMS): A scalable database that allows easy addition, editing, and deletion of content. An easy-to-use management interface that allows instructors to efficiently manage courses and content. Student Management and Registration System: Capability for students to register and log in to their personal accounts. Detailed information about course progress and outcomes. Secure Payment System: Integration with trusted payment service providers such as Apple Pay and Mada, among others. Ensure that payment transactions are conducted sec...

    $2844 (Avg Bid)
    $2844 平均报价
    142 个竞标

    Looking for a talented Java developer to build a to-do list application with a focus on Object-Oriented Programming (OOP). The application will be simple yet effective, featuring offline usage capability which is crucial for productivity in various environments. Key Requirements: • Application Compatibility: The app must be compatible with Windows, Mac and Android platforms. • Offline Functionality: The app should allow users to continue using without a constant internet connection. Skills and Experience: • Proficient in Java OOP. • Extensive experience developing applications for different platforms. • Good understanding of implementing offline capabilities in applications. Application Guidelines: • Freelancers are require...

    $22 / hr (Avg Bid)
    $22 / hr 平均报价
    30 个竞标

    We are looking for a talented frontend designer proficient in HTML, CSS, and JavaScript to join our team. The ideal candidate should have experience with modern design styles and a proven track record of developing...seamlessly to desktops, tablets, and mobile devices. Key Requirements: Proficiency in HTML, CSS, and JavaScript Ability to create modern design styles Experience in developing responsive websites for all devices Responsibilities: Designing and implementing frontend code for our project Ensuring the website is fully responsive and adaptive across all devices Refining the existing MVP design for desktop and making it responsive for all screens A strong portfolio showcasing previous work with similar requirements is highly beneficial. Some of Screenshot of our MVP are...

    $99 (Avg Bid)
    $99 平均报价
    26 个竞标

    I'm seeking a professional who can assist in generating leads and potentially converting them into clients for my window cleaning business. The leads should be specific to suburban neighborhoods and residential areas, with a primary aim of increasing sales. Key Responsibilities: - Identify and gather leads from the specified suburban neighborhoods. - Develop strategies to convert these leads into potential clients. - Prioritize on generating leads that have a higher likelihood of converting into sales. - Maintain a professional and engaging approach towards potential clients. Free Trial Opportunity: As part of our hiring process, we're offering a free trial period to assess your ability to generate leads effectively. During this trial period, you'll be tasked with ...

    $3 / hr (Avg Bid)
    $3 / hr 平均报价
    7 个竞标
    CAD Line Drawings of House 6 天 left
    已验证

    I have hand-drawn sketches of a house I'll be building. I need these converted to professional CAD line drawings. Key Requirements: - Convert hand-drawn sketches to professional CAD line drawings. - Attention to detail for accuracy and precision. Ideal Skills: - Proficient in CAD software. - Experience in architectural design/construction drawings.

    $20 (Avg Bid)
    $20 平均报价
    37 个竞标

    I'm looking for a skilled developer to create a business website, and I'm open to using either PHP or .NET. Key requirements for this project include: - Implementation of a robust and user-friendly payment gateway integration for seamless transactions. - Integration of a feature that allows businesses to list their business for sale listing on the site. Your experience with development and payment integration will be crucial. Please share relevant experience and approaches in your proposal.

    $480 (Avg Bid)
    $480 平均报价
    199 个竞标