• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.740-743
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• 2012

초기의 운영체제 역할은 컴퓨터와 사용자간의 매개체 역할을 수행하는 것으로 하드웨어 및 프로세스를 관리하고, 사용자가 컴퓨터 시스템을 편리하게 이용하도록 하는 것이다. 이러한 운영체제가 서버나 개인용 컴퓨터뿐만 아니라, 스마트폰 및 태블릿 같은 모바일 기기에 탑재되어 모바일 운영체제를 탄생시켰다. 모바일 운영체제는 다양한 기기의 등장, 클라우드 서비스와 결합, 사용자들의 높은 욕구 등으로 인하여 단순한 임베디드 운영체제가 내장되어 작동하던 TV나 자동차까지 영역을 확대해 가고 있다. 본 논문에서는 모바일 운영체제, N-스크린, 스마트 TV에 대해 알아보고, 주요 스마트 TV 분석을 통하여 앞으로 모바일 운영체제의 동향에 대해 알아본다.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제4권4호
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• pp.141-146
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• 2015

최근 스마트 기기 및 소셜 네트워크 서비스, 스트리밍 서비스 등 IT 기술의 발달로 인해 데이터가 급증하였다. 이러한 환경에 맞춰 대용량 데이터를 처리할 수 있는 기술도 함께 주목받고 있는데, 가장 대표적인 기술이 하둡이다. 하둡은 오픈 소스 기반으로 리눅스 기반의 범용 컴퓨터에서 실행할 수 있도록 설계되었다. 초기 하둡은 보안이 거의 도입되지 않았으나, 사용자가 늘어남에 따라 보안이 필요한 데이터가 증가하면서 2009년 커버로스와 토큰 시스템을 도입한 새로운 버전이 나왔다. 그러나 이 방식은 하나의 비밀키만을 사용하고, 사용자마다 블록에 대한 접근허가를 지정할 수 없다는 문제점과 재전송 공격 및 위장 공격 등이 가능하다는 취약점을 가지고 있다. 따라서 본 논문에서는 이러한 취약점을 보안하면서 성능을 유지하기 위해 사용자들을 논리적인 그룹으로 묶어서 인증하고, 이를 토큰에 반영하는 그룹키 기반의 프로토콜을 제안하였다. 성능평가 결과 키 생성에 따른 오버헤드가 없고, 비밀키 유출에 대한 취약점을 해결하였음을 확인하였다.

• 한국IT서비스학회지
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• 제16권3호
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• pp.167-183
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• 2017

The rapid growth of information technology and mobile service platforms, i.e., internet, google, and facebook, etc. has led the abundance of data. Due to this environment, the world is now facing a revolution in the process that data is searched, collected, stored, and shared. Abundance of data gives us several opportunities to knowledge discovery and data mining techniques. In recent years, data mining methods as a solution to discovery and extraction of available knowledge in database has been more popular in e-commerce service fields such as, in particular, movie recommendation. However, most of the classification approaches for predicting the movie popularity have used only several types of information of the movie such as actor, director, rating score, language and countries etc. In this study, we propose a classification-based support vector machine (SVM) model for predicting the movie popularity based on movie's genre data and social network data. Social network analysis (SNA) is used for improving the classification accuracy. This study builds the movies' network (one mode network) based on initial data which is a two mode network as user-to-movie network. For the proposed method we computed degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality as centrality measures in movie's network. Those four centrality values and movies' genre data were used to classify the movie popularity in this study. The logistic regression, neural network, $na{\ddot{i}}ve$ Bayes classifier, and decision tree as benchmarking models for movie popularity classification were also used for comparison with the performance of our proposed model. To assess the classifier's performance accuracy this study used MovieLens data as an open database. Our empirical results indicate that our proposed model with movie's genre and centrality data has by approximately 0% higher accuracy than other classification models with only movie's genre data. The implications of our results show that our proposed model can be used for improving movie popularity classification accuracy.

• 한국컴퓨터정보학회논문지
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• 제21권8호
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• pp.57-64
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• 2016

Initial prevention activities and rapid propagation conditions is the most important to prevent diffusion of water pollution. If water pollutants flow into streams river or main stresm located in environmental conservation area or water intake facilities, we must predict immediately arrival time and the diffusion concentration to the proactive. National Institute of Environmental Research developed water pollution incident response prediction system linking dam and movable weir. the system is mathematical model which is updated daily. Therefore it can quickly predict the arrival time and the diffusion concentration when there are accident of oil spills and hazardous chemicals. Also we equipped with mathematical model and toxicity model of EFDC(Environmental Fluid Dynamics Code) to calculate the arrival time and the diffusion concentration. However these systems offer the services of an offline manner than real-time control services. we have ensured the reliability of data collection and have developed a real-time water quality measurement data transmission device by using the data linkage utilizing a mode bus communication and a commercial SCADA system, in particular, we implemented to be able to do real-time water quality prediction through information infrastructure of the water quality integrated management business created by utilizing the construction of the real-time prediction system that utilizes the data collected, the Open map, the visual representation using charts API and development of integrated management system development based on web maps.

• 한국응급구조학회지
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• 제18권2호
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• pp.125-136
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• 2014

Purpose: We aimed to improve the survival rates of out-of-hospital cardiac arrest patients. Methods: We analyzed data regarding cardiopulmonary resuscitation (CPR) outcomes and clinical characteristics of out-of-hospital cardiac arrest patients. The data included prehospital emergency medical service reports of 207 patients, 135 patients of Heart Saver, who survived over 72 hours after return of spontaneous circulation (ROSC) in Gyeonggi-do from January, 2012 to December, 2013. Data were analyzed using SPSS 18.0 descriptive statistics. Results: Among patients who achieved ROSC, 87.6% were men and 73.6% were aged 41-70 years; 86.7% were cases of witnessed cardiac arrest, and cardiopulmonary resuscitation was performed by bystanders in 65.9% of cases. The initial electrocardiogram showed ventricular fibrillation or pulseless ventricular tachycardia in 96.3% of patients. The call time was 1.0 minutes, arrival time was 6.3 minutes, time spent at the scene was 8.0 minutes, hospital arrival time was 10.0 minutes, and total CPR duration was 9.6 minutes. The certificate of them was paramedics in 89.6%. Conclusion: To improve the survival rates of out-of-hospital cardiac arrest patients, standard prehospital care for these patients and educational programs regarding CPR for lay rescues should be developed.

• 대한영양사협회학술지
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• 제24권2호
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• pp.117-140
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• 2018

The number of patients is increasing and their mean age is also increasing. Proper dietary adjustments are necessary to prevent protein-calorie malnutrition or complications but it is difficult for dialysis patients to adapt to diet therapy due to stress or anorexia. Education does not consider the individual characteristics, knowledge, dietary inhabit education demands, and initial education. The purpose of this study was to identify dialysis patient's nutrition knowledge and, dietary practice and compare those with nutrition education or counseling demands for providing basic data of desirable nutrition management. The data were collected by a survey consisting of the general characteristics, disease related characteristics, nutrition education and counsel characteristics, level of nutrition knowledge, diet therapy, and nutrition education and counsel demands from the 28th March to 22th July 2017. The total number of subjects were 33 patients among dialysis patients at two tertiary medical institutions and an artificial kidney room at a private hospital in Incheon Gyeonggi. The data collected were analyzed statistically using the SPSS program 23.0, followed by further analyses using frequency analysis, one-way ANOVA, cross analysis, and correlation analysis. The results of the dialysis patients showed that younger (P<0.05), female (P<0.05), abnormal high school diploma (P<0.001) groups had high nutrition scores. In addition, dietary practice and nutrition education and counsel demands showed a positive correlation (P<0.05, P<0.01). In particular, females were higher than males in nutrition knowledge, dietary practice, nutrition education, and counseling demand scores.

• 한국건축시공학회지
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• 제17권1호
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• pp.83-90
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• 2017

최근 건설 산업은 BIM 도입을 의무화 하는 정책과 클라우딩 시스템, 각종 센서기술, 3D 스캐닝 및 프린팅 기술 등의 ICT기술들과 융합으로 BIM이 더욱 활성화 되고 있다. 하지만 그에 따른 표현 수준이 다양해지면서 하나의 BIM 프로젝트 내에서 계획, 설계, 엔지니어링, 시공 등 각 분야마다 서로 다르게 적용되어 일관성을 갖기 어렵다. 따라서 BIM 적용에 대한 효율성이 떨어지고 발주처의 입장에서 사업초기 단계에 적절한 BIM의 수준을 결정하기 힘들다. 본 연구에서는 이를 해결하기 위해 IT 분야에서 사용하는 SLA을 활용하여 발주단계에서 사업에 적합한 BIM의 목표수준을 정하고 평가할 수 있는 방안을 모색하고자 한다.

• 설비공학논문집
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• 제18권11호
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• pp.915-922
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• 2006

Considering heat pipe design principles in fabrication and operational performances, water is one of the most recommended working fluids to make mid to low tempera lure heat pipes. But the conventional water heat pipes might encounter the failure in a cold start-up operation when socked at a chilling temperature lower than the freezing point. If they are subjected to a heat supply for start-up at a temperature around $-20^{\circ}C$, the rate of the vapor flow and the corresponding heat transfer from the evaporator to the condenser is so small that the vapor keeps to stick on the surface of the chilling condenser wall, forming an ice layer, resulting in a liquid deficiency in the evaporator. This kind of problems was resolved by Kang et al. in 2004 by adopting a gas loading heat pipe technology to the conventional water heat pipes. This study was conducted to examine a chilling start-up procedure of gas loading heat pipes by investigating the behaviors of heat pipe wall temperatures. And the thermal resistance of the gas loaded heat pipe that depends on the operating temperatures and heat loads was measured and examined. Two water heat pipes were designed and fabricated for the comparison of performances, one conventional and the other loaded with $N_2$ gas. They were put on start-up test at a heat supply of 30 W after having been socked at an initial temperature around $-20^{\circ}C$. It was observed that the gas loaded one had succeeded in chilling start-up operation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권6호
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• pp.3074-3091
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• 2019

With the widespread use of the Internet, services for providing large-capacity multimedia data such as video-on-demand (VOD) services and video uploading sites have greatly increased. VOD service providers want to be able to provide users with high-quality keyframes of high quality videos within a few minutes after the broadcast ends. However, existing keyframe extraction tends to select keyframes whose quality as a keyframe is insufficiently considered, and it takes a long computation time because it does not consider an HD class image. In this paper, we propose a keyframe selection method that flexibly applies multiple keyframe quality metrics and improves the computation time. The main procedure is as follows. After shot boundary detection is performed, the first frames are extracted as initial keyframes. The user sets evaluation metrics and priorities by considering the genre and attributes of the video. According to the evaluation metrics and the priority, the low-quality keyframe is selected as a replacement target. The replacement target keyframe is replaced with a high-quality frame in the shot. The proposed method was subjectively evaluated by 23 votes. Approximately 45% of the replaced keyframes were improved and about 18% of the replaced keyframes were adversely affected. Also, it took about 10 minutes to complete the summary of one hour video, which resulted in a reduction of more than 44.5% of the execution time.

• 한국정보통신학회논문지
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• 제26권7호
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• pp.1047-1059
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• 2022

클라우드 컴퓨팅 기술의 발전으로 가상 환경을 기반으로 서비스를 제공하는 컨테이너 기술 또한 발전하고 있다. 컨테이너 오케스트레이션 기술은 클라우드 서비스를 위한 핵심적인 요소이며, 대규모로 구성된 컨테이너를 빌드, 배포, 테스트하는데 자동화로 관리하기 위한 중요한 핵심 기술이 되었다. 최초 구글에 의해 설계되었고, 현재 리눅스 재단에 의해 관리되고 있는 쿠버네티스는 컨테이너 오케스트레이션 중에 하나이며 사실상 표준으로 자리 매김을 하고 있다. 하지만 컨테이너 오케스트레이션 중 쿠버네티스의 사용이 증가하고 있음에도 불구하고, 보안 취약점에 의한 사고사례도 또한 증가하고 있다. 이에 본 논문에서는 쿠버네티스의 취약점을 연구하고, 위협 분석을 통해 개발 초기 또는 설계 단계에서부터 보안을 고려할 수 있는 보안 정책을 제안한다. 특히, STRIDE 위협 모델링을 적용하여 보안 위협을 분류함으로써 구체적인 보안 가이드를 제시하고자 한다.