• Journal of the Institute of Convergence Signal Processing
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• v.15 no.2
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• pp.30-36
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• 2014

Quality and resolution of camera in mobile device is improved significantly. In this paper, we propose block-based information hide techniques without image distortion for mobile device to solve image degradation in conventional watermarking methods. Information of image is composed with text such as camera maker, model, date, time, etc. Each text is converted to $8{\times}8$ pixel blocks and is added to the bottom of image. Generally image including block based information for image authentication are compressed using JPEG in mobile device. The vertical line value in JPEG header is modified by original size of image sensor. This technique can hide the block based authentication information using general decoder. In the experimental results, JPEG file size is slightly increased within 0.1% for the proposed block based authentication information encoding. Finally proposed methods can be adopted for various embedded systems using medical image, smart phone and DSLR camera.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.619-622
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• 2005

When Digital Contents goes through production${\cdot}$delivery${\cdot}$consumption, MPEG(Moving Picture Expers Group)-21 IPMP(Intellectual Property Management and Protection) defines standard which have defined by FCD(Final Committee Draft) level to keep the Digital Contents in safety. And development of system which applied to latest standard to protect and manage the broadcasting contents is required. Currently, the system to protect and manage the broadcast contents consists of fourth organizations which means production server, tool server, license server, consumption server. In this paper, we made production server to parse REL(Right Expression Language) document that has right information for content from license server, and create metadata based on MPEG-21 IPMP about the content that applied to watermark. then, after it do remuxing, transmit the protected data to consumption server.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2777-2781
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• 2001

This paper presents an algorithm of the watermark insertion and extraction on the vector image. Most parts of the vector image consist of the array of the coordinate values. The vector watermarking method by Sakamoto et al [1] uses the mask within which all the coordinate values of all the vertices are changed depending on the value of the watermark. The proposed algorithm is the change of the vector image file instead of the change of the coordinate values on the vector image. We use the Drawing Exchange Format (DXF) files since the DXF file is one of the general files in the field of the vector image.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.1
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• pp.23-34
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• 2010

As the number of user increases according to the improvement of the network, the multi-thread schemes are used to process the service requests of several users who are connected simultaneously. The static thread pool scheme has the problem of occupying a static amount of system resources. On the other hand, the dynamic thread pool scheme can control the number of threads according to the users' requests. However, it has disadvantage that this scheme cannot react to the requests which are larger than the maximum value assigned. In this paper, a web server using a learning-based dynamic thread pool scheme is suggested, which will be running on a server programming of a multi-thread environment. The suggested scheme adds the creation of the threads through the prediction of the next number of periodic requests using Auto Regressive scheme with the web server apache worker MPM (Multi-processing Module). Unlike previous schemes, in order to set the exact number of the necessary threads during the unchanged number of work requests in a certain period, K-Nearest Neighbor algorithm is used to learn the number of threads in advance according to the number of requests. The required number of threads is set by comparing with the previously learned objects. Then, the similar objects are selected to decide the number of the threads according to the request, and they create the threads. In this paper, the response time has decreased by modifying the number of threads dynamically, and the system resources can be used more efficiently by managing the number of threads according to the requests.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.95-98
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• 2003

전 세계에 위성이동통신 서비스를 제공하고 있는 인마새트 시스템은 해사통신 및 선박의 안전운항을 목적으로 UN산하 국제해사위성기구(INMARSAT: International Maritime Satellite Organization)로 설립되었다. 그 후 기존에 제공하던 해상 위주의 서비스 외에 항공 및 육상 이동통신서비스가 추가되면서 국제이동위성기구(INMARSAT: International Mobile Satellite Organization)라는 이름과 병행하여 사용하여 오다가 최근 민영화되었다. 이에 따라 인마새트는 육상, 해상, 항공서비스를 제공하면서 86개의 회원국으로 운영되어오다가 민영화되면서 이들 회원국은 모두 투자사로 전환되었다. 하지만 기존에 제공하여온 해상조난안전통신 등 공익성을 갖는 기능에 대해서는 향후에도 지속적인 서비스가 제공되도록 별도로 IMSO(International Maritime Satellite Organization)라는 감독기관을 두어 관장하고 있다. 인마새트는 전세계적으로 글로벌 위성이동통신 서비스를 최초로 제공한 이래 아직까지도 해상, 육상, 항공 등 전 분야에 통신서비스를 제공하는 유일한 사업자이다. 더구나 최근 저궤도 위성을 이용한 GMPCS의 성장추세가 예상보다 크게 둔화되면서 상대적으로 비용이 저렴한 정지궤도 위성 시스템인 인마새트 서비스가 더욱 활성화되는 추세이다. 이에 인마새트 서비스를 위한 신형 장비도 추가 개발되고 있으며 서비스 영역이 확장되는 등 그 중요성이 부각됨에 따라 향후 상당기간동안 인마새트 시스템에 부가기능을 추가하면서 재난시 비상연락수단은 물론이고 일상적인 통신수단의 영역까지 확대될 것으로 전망된다.인 방법이다. 활성물질의 생성시간과 가공시간은 불과 수십 $\mu\textrm{s}$ 및 수 sec 에 불과하므로, 1 kton/h 용량의 수산기활성제 제조장치의 환산소비동력은 약 200 kW이고, 장치의 체적은 10~30 ㎥의 공간으로 충분하므로, 소형선박으로 상당면적의 적조피해를 효과적으로 해결할 수 있다.의 특성을 이용하여 워터마크를 삽입한다.송 시스템을 구현될 수 있음을 검증하였다.출량을 비교한 결과 토사 유출 억제효과는 한지형과 나지형잔디들의 혼합형(MixtureIII)과 자생처리구(MixtureV), Italian ryegrass와 자생식물의 혼합형(MixtureIV)등에서 비교적 낮은 수치를 토사유출량을 기록하였다. 이러한 결과는 자생식물들이 비록 초기생육속도는 외래도입초종에 떨어지지만 토사유출의 억제효과면에서는 이들 외래초종에 필적할 수 있음을 나타낸다고 할 수 있겠다.중량이 약 115kg/$m^2$정도로 나타났다.소 들(환경의 의미, 사람의 목적과 지식)보다 미학적 경험에 주는 영향이 큰 것으로 나타났으며, 모든 사람들에게 비슷한 미학적 경험을 발생시키는 것 이 밝혀졌다. 다시 말하면 모든 사람들은 그들의 문화적인 국적과 사회적 인 직업의 차이, 목적의 차이, 또한 환경의 의미의 차이에 상관없이 아름다 운 경관(High-beauty landscape)을 주거지나 나들이 장소로서 선호했으며, 아름답다고 평가했다. 반면에, 사람들이 갖고 있는 문화의 차이, 직업의 차 이, 목적의 차이, 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을

• Journal of Internet Computing and Services
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• v.16 no.2
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• pp.67-75
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• 2015

According to the changes of the mobile environments, the usage and interest of the Android apps have been increased. But the usage of illegally-copied apps has been also increased. And the transparency and dependability of the app markets has been decreased. Therefore there are many cases for the copyright infringement of app developers. Although several methods for preventing illegally-copied apps have been studied, there may exist possible ways to bypass the methods. Since it is difficult to find out the first distributors of the illegally-copied apps, it is not easy to punish them legally. This paper proposes the method of detecting illegally-copied apps. The proposed detector can detect the illegally-copied apps using odex file, which is created when the app is installed. The detector can also find out the information of the first distributors based on forensic watermark technique. Since the illegally-copied app detector is running as a service on the system server, it is granted that the detector hides from the users. As an experiment result, the illegally-copied app detector takes on average within 0.2 seconds to detect and delete an illegally-copied app.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.577-580
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• 2006

The rapidly growth of Internet is main factor that activates the Digital Contents market. However imprudent Digital Contents market could be shrunk by imprudent illegal copy and delivery. MPEG(Moving Picture Experts Group) proposed MPEG-21 Multimedia frameworks in order to solve these problem. IPMP is parts of MPEG-21 Multimedia Frameworks, when Digital Contents goes through production delivery consumption, which defines standard to keep the Digital Contents in safety. Currently IPMP defined by FCD(Final Committee Draft) level. Therefore development of system which applied to latest standard to protect and manage the Digital Contents is required. and the system consists of fourth organizations which means Metadata Production server, Tool server, License server, Consumption server. In this Paper, we made production server to parse REL(Rights Expression Language) document that has right information for content from license server, and create metadata based on MPEG-21 IPMP about the content that applied to watermark. then, after it do remuxing, transmit the protected data to consumption server.