• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.137-142
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• 2016

A two-step open system(TOS) was proposed to relay between a healing platform and a repository of personal health documents. TOS was designed by taking into consideration the pubsub service based on large scale connections to monitor a provider's access/request process for health documents in real time. TOS, however, uses WebSocket as a communication protocol in case of pubsub. Given the operational environment of low quality wireless networks for mobile devices that are user terminals in a healing platform, there is a need to add a messaging protocol to support QoS as well as a transmission protocol. As a light messaging protocol optimized for mobile devices, MQTT defines reliable messaging QoS to consider a wireless network situation of low speed/low quality. This study designed an MQTT protocol-based message broker to support QoS in case of large scale connections and pubsub by taking into consideration mobile devices that are user terminals in a healing platform. After designing a model between TOS and MQTT message broker, the study implemented a prototype based on the proposed design and compared it with its counterparts from previous studies based on the performance indicators in a load-test with the MQTT client tool.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.987-994
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• 2010

In this paper, a simple and effective active load-pull method is proposed, and the method to improve the efficiency of X-band power amplifier using harmonic control circuit is presented. The proposed active load-pull system mainly consists of directional coupler, phase shifter, short circuit, and power amplifier, and allows a user to access reflection coefficients near the edge of the Smith chart($\Gamma$=1) easily. The device used in this paper is Mitsubishi's GaAs FET MGF1801, and the operating frequency of the power amplifier is 9 GHz, The amplifier had output power of 21.65 dBm and drain efficiency of 24.9 % at class-A, and had output power of 21.46 dBm and drain efficiency of 53.3 % at class-AB. Harmonic control circuit is designed only second and third harmonic components because of the bandwidth limitation of the microwave components. The drain efficiency is improved as much as 6.4 % compared with class-AB power amplifier.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.4
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• pp.414-420
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• 2018

The digital convergence looking for new ways to engage visitors by superimposing virtual content on projection over the real world captured media contents. This paper propose the Light ID based interactive 3D immersive exhibition things view using HMD AR technology. This approach does not required to add any additional infrastructure to be built-in to enable service and uses the installed Lighting or displays devices in the exhibit area. In this approach, the Light ID can be used as a Location Identifier and communication medium to access the content unlike the QR Tag which supports provide the download information through web interface. This utilize the advantages of camera based optical wireless communication (OWC) to receive the media content on smart device to deliver immersive 3D content visualization using AR. The proposed exhibition method is emulated on GALAXY S8 smart phone and the visual performance is evaluated for Jeonju Hanok Village. The experimental results shows that the proposed method can give immersive 3D view for exhibit things in real-time.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.65-71
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• 2016

Although high mammographic density is one of the strongest predictors of breast cancer risk, X-ray based mammography cannot be performed before the recommended screening age, especially not in adolescents and young women. Therefore, new techniques for breast density measurement are of interest. In this pilot study in Guam and Hawaii, we evaluated a radiation-free, bioimpedance device called Electrical Breast Densitometer$^{TM}$ (EBD; senoSENSE Medical Systems, Inc., Ontario, Canada) for measuring breast density in 95 women aged 31-82 years and 41 girls aged 8-18 years. Percent density (PD) was estimated in the women's most recent mammogram using a computer-assisted method. Correlation coefficients and linear regression were applied for statistical analysis. In adult women, mean EBD and PD values of the left and right breasts were $230{\pm}52$ and $226{\pm}50{\Omega}$ and $23.7{\pm}15.1$ and $24.2{\pm}15.2%$, respectively. The EBD measurements were inversely correlated with PD ($r_{Spearman}=-0.52$, p<0.0001); the correlation was stronger in Caucasians ($r_{Spearman}=-0.70$, p<0.0001) than Asians ($r_{Spearman}=-0.54$, p<0.01) and Native Hawaiian/Chamorro/Pacific Islanders ($r_{Spearman}=-0.34$, p=0.06). Using 4 categories of PD (<10, 10-25, 26-50, 51-75%), the respective mean EBD values were $256{\pm}32$, $249{\pm}41$, $202{\pm}46$, and $178{\pm}43{\Omega}$ (p<0.0001). In girls, the mean EBD values in the left and right breast were $148{\pm}40$ and $155{\pm}54{\Omega}$; EBD values decreased from Tanner stages 1 to 4 ($204{\pm}14$, $154{\pm}79$, $136{\pm}43$, and $119{\pm}16{\Omega}$ for stages 1-4, respectively) but were higher at Tanner stage 5 ($165{\pm}30{\Omega}$). With further development, this bioimpedance method may allow for investigations of breast development among adolescent, as well as assessment of breast cancer risk early in life and in populations without access to mammography.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.46-54
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• 2018

The Internet of Things (IoT) is an environment in which various devices provide services to users through communications. Because of the nature of the IoT, data are stored and distributed in heterogeneous information systems. In this situation, IoT end applications should be able to access data without having information on where the data are or what the type of storage is. This mechanism is called Service Discovery (SD). However, some problems arise, since the current SD architectures search for data in physical devices. First, turnaround time increases from searching for services based on physical location. Second, there is a need for a data structure to manage devices and services separately. These increase the administrator's service configuration complexity. As a result, the device-oriented SD structure is not suitable to the IoT. Therefore, we propose an SD structure called Name-based Service-centric Service Discovery (NSSD). NSSD provides name-based centralized SD and uses the IoT edge gateway as a cache server to speed up service discovery. Simulation results show that NSSD provides about twice the improvement in average turnaround time, compared to existing domain name system and distributed hash table SD architectures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.292-295
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• 2003

This paper presents the architecture and its function of Tool server. MPEG-21 will enable all-electronic creation, delivery and trade of digital multimedia content and transparent usage of various content types on network device. Therefore, we can provide access to information and services from almost anywhere at anytime with various terminals and networks. In order to support multimedia delivery chain that contains content creation, production, delivery and consumption, we need some elements to identify, describe, manage and protect the contents. Thus, we define Digital Item Processing(DIP), Digital Item Adaptation(DIA) server and Tool server as primary objects of MPEG-21 multimedia framework. DIP provides a function which creates and consumes Digital Item(DI) as a kind of a digital object by user. DIA server adapts the original DI to the usage environment description sent from the terminal and transmits the adapted DI to the terminal. Tool sewer searches for a tool requested from DIP or DIA and downloads the best tool to DIP or DIA server. In this paper, we present how Tool server is organized and is used among 2 primary objects. The paper is structured as following: Section 1 briefly describes why MPEG-21 is needed and what MPEG-21 wants. We see the basic architecture of tool server and its functionality by each module in section 2. Section 3 explains a scenario that tool server transmits tool to DIP or DIA. The paper concludes in section 4.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04b
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• pp.731-734
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• 2001

우편물을 집배원이 배달하는 순서로 자동구분 처리하기 위한 요소기술 줌에서 4-state 바코드 시스템이 개발되고 있으며 우편번호, 배달순서코드, 고객정보 등이 적용될 예정이다. 기존의 고객 바코드 판독 시스템은 우편물상의 바코드 심볼로지가 존재하는 판독대상 영역의 기울기가 ${\pm}4.47^{\circ}$ 이하이고, 심볼의 훼손과 잡영이 없을 경우에 $79{\sim}100msec(35,000{\sim}45,000$통/시간)의 속도로 자동 구분 정보가 판독된다. 본 논문에서는 판독범위 및 판독성능을 개선을 위하여 CCD(Charge Coupled Device) 센서로부터 획득된 이미지상에서 존재하는 심볼로지 정보의 고속판독 방법을 제시한 것이다. 이 판독방법은 그레이(gray) 이미지 바탕면의 경계값(threshold) 기울기 분포를 기준으로 2개의 경계값을 설정하여 판독대상 정보를 획득하였다. 또한, 4-state 바코드 심볼로지의 존재 가능성 영역만을 탐색하고, 판독대상 영역에서 트래커(tracker)를 탐색하여 심볼로지의 기울기값, 심볼로지 경계값, 심볼위치 좌표값을 생성한 후 심볼값이 판독한 것이다. 판독시험 결과는 판독대상 영역의 심볼로지가 ${\pm}45^{\circ}$ 기울어지고, 잡영이 존재할 경우에도 $30{\sim}60msec(58,000{\sim}l16,000$통/시간) 이내에 판독되었다. 우편물 자동구분용 바코드 판독기로써 적용될 경우에 판독속도가 평균 57.25% 이상 개선되고, 판독범위의 확장으로 0.2%의 기계적인 오류(이송과정예서의 Jam 발생 비율)를 제외할 경우에 거의 99.8% 우편물을 판독하여 자동구분 처리할 수 있게 될 것으로 기대된다.onebook 엑세스 모들(Server Phonebook Access Module)로 구성되어 있다.외 보다 높았다(I/O ratio 2.5). BTEX의 상대적 함량도 실내가 실외보다 높아 실내에도 발생원이 있음을 암시하고 있다. 자료 분석결과 유치원 실내의 벤젠은 실외로부터 유입되고 있었고, 톨루엔, 에틸벤젠, 크실렌은 실외뿐 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유의성이 움직임 보정 전에 비하여 낮음을 알 수 있었다. 결론: 뇌활성화 과제 수행시에 동반되는 피험자의 머리 움직임에 의하여 도파민 유리가 과대평가되었으며 이는 이 연구에서 제안한 영상정합을 이용한 움직임 보정기법에 의해서 개선되었다. 답이 없는 문제, 문제 만

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.331-342
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• 2017

Objectives: This study aimed at helping oral health prevention of the blind and related management plan, which is defined as the influence factors between missing and filled permanent teeth index and general feature and oral health behavior of the blind in Korea (estimates 229,678 persons) using data of the 6th Korea National Health and Nutrition Examination Survey from 2014 Korea Centers For Disease Control and Prevention. Methods: The blind over the age of 30 were selected as study subjects who have conducted health survey and dental inspections in KNHANES VI-2. Estimates of the subjects were 229,67 persons. For analyzing data, general linear models: GLM and covariance analysis were conducted to identify the relation between general feature and oral health behavior and missing and filled permanent teeth index. SPSS 21 statistical program was used, which is possible to conduct complex sampling design, and the significance level was 0.05. Results: The missing and filled permanent teeth index was 8.58 points. Regarding the results of the analysis, R-squared of the missing and filled permanent teeth index depending on general features of the blind was 0.839 points, which shows gender, age, residence, education level, individual income, disability rating, kinds of health insurance, marital status and recipient of basic living had an effect on the missing and filled permanent teeth index. R2 of the missing and filled permanent teeth index depending on oral health form of the blind was 0.728 points, which shows oral examination, dental treatment, smoking and toothbrushing after lunch had an effect on the missing and filled permanent teeth index. Conclusions: With the result of this study, we found the oral health actual condition of the blind in Korea. Therefore, it is considered that the government needs to introduce the personalized oral health education program to maintain oral health of the blind and to develop a program that uses braille and voice device which enables to access and utilize to improve oral health behavior that the government could use it as a reference to establish the policy plan.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.120-120
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• 2011

Graphene is a carbon based material and it has great potential of being utilized in various fields such as electronics, optics, and mechanics. In order to develop graphene-based logic systems, graphene field-effect transistor (GFET) has been extensively explored. GFET requires supporting devices, such as volatile memory, to function in an embedded logic system. As far as we understand, graphene has not been studied for volatile memory application, although several graphene non-volatile memories (GNVMs) have been reported. However, we think that these GNVM are unable to serve the logic system properly due to the very slow program/read speed. In this study, a GVM based on the GFET structure and using an engineered graphene channel is proposed. By manipulating the deposition condition, charge traps are introduced to graphene channel, which store charges temporarily, so as to enable volatile data storage for GFET. The proposed GVM shows satisfying performance in fast program/erase (P/E) and read speed. Moreover, this GVM has good compatibility with GFET in device fabrication process. This GVM can be designed to be dynamic random access memory (DRAM) in serving the logic systems application. We demonstrated GVM with the structure of FET. By manipulating the graphene synthesis process, we could engineer the charge trap density of graphene layer. In the range that our measurement system can support, we achieved a high performance of GVM in refresh (>10 ${\mu}s$) and retention time (~100 s). Because of high speed, when compared with other graphene based memory devices, GVM proposed in this study can be a strong contender for future electrical system applications.

• Journal of Broadcast Engineering
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• v.5 no.1
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• pp.94-101
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• 2000

User adaptive reception of broadcast programs includes the functionality such as the user adaptive filtering and browsing functionality. The user adaptive filtering means that the user can limit the list of programs to include only his/her favorite programs among hundreds of available programs. The user adaptive browsing means that the user can view a short summary of his/her selection in the way that he/she prefers. When the receiving system include the random access storage device, the automatic recording functionality of users favorite programs can be included. The user adaptive reception requires support from various meta-data such as user preference data and content description data. TV Anytime forum is a standardization effort to enable user adaptive TV reception, which means that the user can watch what s/he wants when s/he want in the way s/he wants. MPEG-7 includes not only the content description for broadcast applications but also other content descriptions such as structure information. This paper addresses the relationship between MPEG-7 and TV Anytime and investigates how MPEG-7 should be designed and be used to satisfy the requirements of the user adaptive reception of broadcast program.