• Journal of the Korea Society for Simulation
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• v.19 no.1
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• pp.161-171
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• 2010

Sensor Networks are often deployed in unattended environments, thus leaving these networks vulnerable to false data injection attacks in which an adversary injects forged reports into the network through compromised nodes. Such attacks by compromised sensors can cause not only false alarms but also the depletion of the finite amount of energy in a battery powered network. Ye et al. proposed the Statistical En-route Filtering scheme to overcome this threat. In statistical en-route filtering scheme, all the intermediate nodes perform verification as event reports created by center of stimulus node are forwarded to the base station. This paper applies a probabilistic verification method to the Static Statistical En-route Filtering for energy efficiency. It is expected that the farther from the base station an event source is, the higher energy efficiency is achieved.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.6
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• pp.149-153
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• 2007

One common type of web-application vulnerabilities is injection flaw, where an attacker exploits faulty application code instead of normal input. In order to be free from injection flaw, an application program should be written in such a way that every potentially bad input character is filtered out. This paper proposes a precise analysis that statically checks whether or not an input string variable may have the given set of characters at hotspot. The precision is accomplished by taking the semantics of condition into account in the analysis.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.13-16
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• 2007

본 논문에서는 동적 추천 기능이 있는 자바 기반 음악 추천 서버를 소개한다. 본 논문에서 소개하는 추천 서버는 각 음악 사이의 유사도를 그래프로 저장하는 그래프 기반 협동적 여과 방식을 사용하며, 독립된 서버로 구성되어 클라이언트와 정해진 프로토콜에 따라 통신하도록 구현되었다. 또한 이 추천 서버는 특정 사용자나 특정 음악의 정적인(static) 성향뿐 아니라 시간에 따라 달라지는 동적인(dynamic) 성향에 맞는 추천도 가능하도록 설계되었다. 정적 성향이란 어떤 사용자가 가지고 있는 음악에 대한 기본적인 취향을 나타내고, 동적 성향이란 특정한 상황이나 분위기에 따라 유동적으로 변하는 성향을 의미한다. 본 논문에서 소개하는 추천 서버는 정적 성향과 동적 성향에 대하여 각각 추천할 수 있는 기능을 가지고 있으며, 이러한 기능을 바탕으로 실제 사용자들의 음악 다운로드 데이터를 이용하여 추천 데모 사이트를 구축하였다.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.521-529
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• 2007

In this paper, we introduce a music recommendation system that automatically recommends music according to users' musical tastes. The recommendation system uses a graph-based collaborating filtering in which similarities between musics are saved as a graph, and so it can perform fast recommendation based on the implicit preference information. It also has capability of recommending music according to users' dynamically changing preferences as well as users' static preferences. The recommendation server is implemented as an independent server using Java, and communicates with clients according to a specified protocol. A demo web site has been built by using the server and music download data from actual users, and the accuracy of recommendation has been measured through experiments.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.110-116
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• 2002

Here are shown on stress and vibration evaluations and application of piping system in petrochemical plant with and actual example. While stress evaluation by thermal growth has no argument on the calculated results, vibrational evaluations have some different results in accordance with the evaluation methods. In case of the static stress evaluation the ASME B3l.3 code defines 7000 cycles of fatigue lift: in operating the piping system with a design condition. However, the method of vibrational evaluation on piping systems in petrochemical plants has not been established clearly, yet. In this stuffy, it is purposed to present the requirement of a vibrational evaluation method for petrochemical plant piping system, with an actual application.

• Journal of Korean Medical classics
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• v.18 no.2 s.29
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• pp.20-44
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• 2005

통과한의학화서양의학적원리연구심신적상호관계(通過韓醫學和西洋醫學的原理硏究心腎的相互關係), 득도료여하결론(得到了如下結論) 경연구심신지간재한의학상구유(經硏究心腎之間在韓醫學上具有): 심양여신음유'심신상교'적'수화기제'관계(心陽與腎陰有'心腎相交'的'水火旣濟'關係). 차외환유신양(명문화)여심양(심화)적상호의존관계(此外還有腎陽(命門火)與心陽(心火)的相互依存關係). 우유심장신여신장정적상호의존관계이지유신정충족시(又有心藏神與腎藏精的相互依存關係而只有腎精充足時), 재가이사심주신지적공능유지정상(才可以使心主神志的功能維持正常). 경연구심신지간재서양의학상구유(經硏究心腎之間在西洋醫學上具有): 제일(第一), 심장여신장재해부학상밀절연계(心臟與腎臟在解剖學上密切聯係), 즉종심장좌심실분지출신동맥(卽從心臟左心室分枝出腎動脈), 진이형성신소구등신장적혈관구화모세혈관강(進而形成腎小球等腎臟的血管球和毛細血管綱). 제이(第二), 심장향신장공응혈액(心臟向腎臟供應血液), 신장시인체중접수혈공최다적장기(腎臟是人體中接受血供最多的臟器). 제삼(第三), 심장통과심납소(ANP)적분비(的分泌), 증가신혈류양급신소체여과율(增加腎血流量及腎小體濾過率). 제사(第四), 신장통과신소(腎臟通過腎素)(renin)적분비조절혈압(的分泌調節血壓). 제오(第五), 신공능부전대심장구성부면영향(腎功能不全對心臟構成負面影響). 제육(第六), 심장여신장지간종서양의학적각도고려(心臟與腎臟之間從西洋醫學的角度考慮), 야존재착상생화상극관계(也存在着相生和相克關係). 경연구심신적상호관계재수행중적작용(經硏究心腎的相互關係在修行中的作用), 득출여하결론(得出如下結論): 제일(第一), 수행영인안정심지(修行令人安定心志), 사심화하강(使心火下降). 제이(第二), 수행시적호흡조절조폐금생신수(修行時的呼吸調節助肺金生腎水), 저시소유적수행법도재중시호흡조절적근본이유(這是所有的修行法都在重視呼吸調節的根本理由). 제삼(第三), 수행시발생수승화강(修行時發生水昇火降). 저실제상시의뢰심화중적일음효여신수중적일양효적발동내완성(這實際上是依賴心火中的一陰爻與腎水中的一陽爻的發動來完成). 제사(第四), 통과수행(通過修行), 가이달도보정적목적(可以達到保精的目的), 유차보장생명적지보(由此保藏生命的至寶). 제오(第五), 통과수행(通過修行), 가이달도연정화기(可以達到煉精化氣), 약능주도연정화기(若能做到煉精化氣), 가사인체불누설정액(可使人體不漏泄精液), 반이화기이증강인체기능(反而化氣以增强人體機能), 시보정적유효수단(是保精的有效手段). 수행적관건시'남자수성불누정(修行的關鍵是'男子修成不漏精), 여자수성온불누경(女子修成不漏經)'.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.745-756
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• 2009

An autonomous virtual character can conduct itself like a human after recognizing and interpreting the virtual environment. Artificial vision is mainly used in the recognition of the environment for a virtual character. The present artificial vision that has been developed takes all the information at once from everything that comes into view. However, this can reduce the efficiency and reality of the system by saving too much information at once, and it also causes problems because the speed slows down in the dynamic environment of the game. Therefore, to construct a vision system similar to that of humans, a visual observation system which saves only the required information is needed. For that reason, this research focuses on the descriptive artificial intelligence engine which detects the most important information visually recognized by the character in the virtual world and saves it into the memory by degrees. In addition, a visual system is constructed in accordance with an image transaction theory to make it sense and recognize human feelings. This system finds the attention area of moving objects quickly and effectively through the experiment of the virtual environment with three dynamic dimensions. Also the experiment enhanced processing speed more than 1.6 times.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.3-9
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• 2013

Purpose: Currently commercially available phantom can reproduce and evaluate only a static situation, the study is incomplete research on phantom and system which is can confirmed functional situation in the kidney by time through dynamic phantom and blood flow velocity, various difference according to the amount of radioactive. Therefore, through this study, it has produced the dynamic kidney phantom to reproduce images through the dynamic flow of the kidney, it desire to evaluate the usefulness of nuclear medicine imaging. Materials and Methods: The production of the kidney phantom was fabricated based on the normal adult kidney, in order to reproduce the dynamic situation based on the fabricated kidney phantom, in this study it was applied the volume pump that can adjust the speed of blood flow, so it can be integrated continuously radioactive isotopes in the kidney by using $^{99m}Tc-pertechnate$. Used the radioactive isotope was supplied through the two pump. It was confirmed the changes according to the infusion rate, radioactive isotopes and the different injection speeds on the left and right, analysis of the acquired images was done by drawn ten times ROI in order to check the reproducibility of each on the front and rear of the kidney and bladder. Results: Under the same conditions infusion rate 40 mL/min fixed to adjust the pressure of the pump when the radiopharmaceuticals between 2-3 minutes in the most integrated in the kidney phantom was excreted inthe bladder. Glomerular filtration rate (GFR), respectively, by each device SYMBIA 1,091 mL/min, FORTE 1,232 mL/min, ARGUS 1,264 mL/min, INFINIA 1,302 mL/min in that there isno statistically significant difference was found, Tmax values and T1/2 values stars from all equipment with no statistically significant difference was found. CV values of the coefficient of variation less than 5% was found to be repeatable, and to 2.67% of the lowest SYMBIA appeared, INFINIA was the highest in the 4.86%. Conclusion: Through this study, the results showed that the dynamic kidney phantom system is able to similarly reproduce renogram in the actual clinical. Especially, the depicted over time for the flow to be excreted through the kidney into the bladder was adequately reproduce, it is expected to be utilized as basic data to check the quality of the dynamic images. In addition, it is considered to help in the field of functional imaging and quality control.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.1
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• pp.76-82
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• 2017

Purpose Whole body bone scan is one of the most frequently performed in nuclear medicine. Basically, both the anterior and posterior views are acquired simultaneously. Occasionally, it is difficult to distinguish the lesion by only the anterior view and the posterior view. In this case, accurate location of the lesion through SPECT / CT or additional static scan images are important. Therefore, in this study, various improvement activities have been carried out in order to enhance the work capacity of technologists. In this study, we investigate the effect of technologist training and standardized work process processes on bone scan error reduction. Materials and Methods Several systems have been introduced in sequence for the application of new processes. The first is the implementation of education and testing with physicians, the second is the classification of patients who are expected to undergo further scanning, introducing a pre-filtration system that allows technologists to check in advance, and finally, The communication system called NMQA is applied. From January, 2014 to December, 2016, we examined the whole body bone scan patients who visited the Department of Nuclear Medicine, Asan Medical Center, Seoul, Korea Results We investigated errors based on the Bone Scan NMQA sent from January 2014 to December 2016. The number of tests in which NMQA was transmitted over the entire bone scan during the survey period was calculated as a percentage. The annual output is 141 cases in 2014, 88 cases in 2015, and 86 cases in 2016. The rate of NMQA has decreased to 0.88% in 2014, 0.53% in 2015 and 0.45% in 2016. Conclusion The incidence of NMQA has decreased since 2014 when the new process was applied. However, we believe that it will be necessary to accumulate data continuously in the future because of insufficient data until statistically confirming its usefulness. This study confirmed the necessity of standardized work and education to improve the quality of Bone Scan image, and it is thought that update is needed for continuous research and interest in the future.