• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.40-47
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• 2015

We propose a method to provide a selective VoD service during live streaming sessions. In the proposed method, each peer joined the live streaming session receives video stream packets with P2P manner and stores the packets to provide a VoD service. To mitigate the overhead of each peer node to store the video stream packets, the proposed scheme categorizes peers into three different groups based on their link types. To increase data gathering speed and reduce the network load, we also proposes the P2P transmission scheme within the same AP network for the peers with Wi-Fi link. To evaluate the performance of the proposed method, we implement computer simulator using NS-3. Simulation results show that the proposed method reduces the overhead about 66% and increases the P2P data gathering speed about 50% compared to the conventional schemes.

• Journal of the Korean housing association
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• v.3 no.2
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• pp.89-99
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• 1992

We discussed the change of housing environmental problems from the early 1900s to the present in Study(I). This study(II) which secendly research of study(I) analyzed the fixing precess of a lavatory centering around a excretion which was a serious housing environmental problem in 1920 to 1940. The documentary research method was used for this study. Articles of content analysis(N=185) were published in 1920 to 1990 which were The Deng-A daily news article about a excretion and a lavatory. The main content of this study was examined the change, such as the number of whole article, the column number of article by time series. and the content of article by subject. 1. The number of whole article by time series was collected mainly in1920s-1930s. In 1940s-1960s, one-two column of article was appeared generally and three-four, five column of article was appeared in 1970-1980. 2. Contents of article was divided into two classes, excretion and lavatory. Contents of excretion was 1) a use of fertilizer 2) the method of transportation 3) a cost of gathering 4) a place of disposal 5) the problem of cleaning. Contents of lavatory was 1) a public lavatory 2) a flush toilet 3) a sanitary conditions 3. 1) A use of fertilizer was concentrated in 1920s-1930s, and problems of it was solved more or less by change of management method. Transportation of excretion developed such as \ulcornerGue\ulcorner->a coach of tank style->underground transportation->a dung car of absorption style. Disposal place of excretion was a cause of dissatisfaction in 1920s and it is serious problem Today. A duty of excretion gathering was transfered to a private worker in 1978. The accunulation problem of excretion was continued until 1940s-1950s. The management law of waste matters was proclaimed in 1986. 2) A public lavatory was planned in 1924 for the first time, and it is insufficient in these days, A settlement of public lavatory in building which has upward of 20pyung became obligation in 1973. The problem of water contamination which by poor septic tank was happened in 1970s-1980s.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.6
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• pp.1143-1156
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• 2013

Power control system like SCADA(Supervisory Control And Data Acquisition) is gathering information using RS232C and low-speed analog communication network. In general, these methods are known as secure because of the secure characteristics from the analog based communication network and serial communication. In this study, first we build DNP communication environment using commercial power control simulator and find some vulnerabilities by testing from the viewpoint of confidentiality, integrity and availability. Consequently, we see the necessity of a valid method for authentication and data encryption when gathering information, even though that is known as secure so far. Discussion of needs of DNP authentication and data encryption is started about several years ago, but there is still nowhere applied that on real environment because the current methods can not fully meet the security requirements of the real environment. This paper suggests a solution to the vulnerabilities, and propose some considerations for enhancing power control system's security level by applying DNP authentication and data encryption.

• Journal of The Korean Association For Science Education
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• v.13 no.1
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• pp.56-65
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• 1993

The purpose of this study is to analyze the inquiry activities of SCIIS and Korea primary school science curricular meterials and to make suggestions for the improvement of inquiry learning based on the analysis The Scientific Inquiry Evaluation Inventory (SIEI: Myung Hur, 1984) was used to evaluate the inquiry activity content of the primary school "Science, Level-6" and "SCIIS, Level-6" textbooks. The results are as follows: 1) The inquiry activities of Korean science textbooks are stressing on gathering and organizing data, but rarely require students to formulate a hypothesis, to design an experiment. 2) The SCIIS textbooks relatively tended to put more weight on interpreting/ analysing data and hypothesizing/ designing experiments. 3)The Korean science textbooks had little concern about establishing hypothesis and designing experiments, interpreting / analysing data. 4) The SCIIS textbooks require students to perform a variety of inquiry skills when compare to Korean science textbooks. 5) Competition / Cooperation Scale checks the level of competition and cooperation among student teams inherent in science curricular materials. The result from each team is incorporated into the formation of a class result. The communication is required to formulate a synthesized class response, enhances cooperation among teams. The SCIIS(84%) is the higher than Korea(50%) in cooperation scale. 6) Korean science textbooks rarely require students to discuss about experiment when compare to SCIIS textbooks. 7) Korean science textbooks provide students with both inquiry problems and experimental procedure, or including answers SCIIS textbooks provide students with both inquiry problems and experimental procedure, or problems only. 8) The Korean textbooks emphasize demonstrating or verifying of the text while the SCIlS emphasize extending the content of the text in inquiry scope scsle. The inquiry pyramid which helps analysis the inquiry activity curriculum as a whole is one of type 1- the course is centered on gathering and organizing data. The SCIIS are better than the Korean science textbook in the light of proportion of interpreting / analysing data and hypothesizing / designing experiments.

• Journal of The Korean Association of Information Education
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• v.17 no.1
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• pp.73-81
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• 2013

Elementary students are living in the information environment at daily. Also, they are learning the school curriculum lessons are based on information. Computational thinking that based on information from everyday life and the school curriculum is important. Until now, many educational materials for the computational thinking have been developed. But, teaching and learning method for computational thinking have not been developed. In the study, the teaching and learning model for computational thinking for elementary school students will be developed. Computational thinking education model proposed in this study consists of three phases. The first phase is the information gathering stage. The second phase is to perform calculations. The last phase is the decision-making steps. Effective teaching and learning methods that are proposed model in this study for computational thinking education will be used.

• Journal of KIISE:Software and Applications
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• v.34 no.5
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• pp.419-430
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• 2007

It is very important to track whether software is properly developed according to requirements. This study suggests a method to track requirements by using a tracking table. In this study, the tracking table indicates why such requirements are included by detailing the content of requests for proposals and proposals. The table also facilitates verification of the consistency between outputs and the integrity by having ID codes of each requirement mapped to each output. Furthermore, as this study was conducted, it was found that some factors were required to be added or supplemented to the outputs at the requirement gathering stage of MaRMI-Ⅲ v.4.0 methodology. Thus, this study seeks to present this additional result along with the enhanced tracking table. By verifying outputs, the tracking table presented in this study will help to reduce all kinds of risks and problems that may occur in software development due to the lack of management of requirements. In addition, the output of the requirement-gathering stage of MaRMI-Ⅲ v.4.0 methodology will be improved/supplemented according to the creation of tracking tables; this will increment the applicability of the MaRMI-III methodology.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.107-127
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• 2010

This research is about the monitoring of people's consciousness on ecosystem change after coastal restoration project in Gangjin Bay. Tidal flat ecosystem of Ganjin Bay was major producing district of short-necked clam in Jeonnam Province. Owing to coastal restoration project (sand gathering and dredging) during 5 years, however, ecosystem was disturbed and harvesting of fish was decreased. Although a few of ark shell and oyster are harvested but drastically decreased. Even aging and depopulation is general situation like other rural regions, life pattern of villages and depopulation in Gangjin Bay was influenced by drastic decreasing of income. As the results of social monitoring, drastic decreasing of fish and shell in Gangjin Bay is significantly concerned with coastal restoration project (sand gathering and dredging) and also with difficulty of fresh-water inflow to coastal bay because of Jangheung Dam. In order to get the detail information on the cause and consequence of ecosystem change in tidal flat, it is necessary to apply the long-term socio-economic monitoring as well as biological and ecosystem monitoring.

• Corrosion Science and Technology
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• v.16 no.6
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• pp.285-293
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• 2017

The effects of sulfate reducing bacteria (SRB) on the corrosion and scaling of the Q235 carbon steel has been investigated in the simulated sewage water and oil field gathering pipelines production water, using scanning electron microscopy (SEM), energy dispersive x-ray spectrometry (EDS), and three-dimensional stereoscopic microscope. Results indicated that the concentration of SRB reached the maximum value on the ninth day in simulated sewage water with a large amount of scaling on the surface of specimen. In oil field gathering pipelines, a large amount of scaling and mineralization of mineral salts and thick deposition of extracellular polymeric substance (EPS) layers were also observed on the surface of specimen. The thickness of biofilm was about $245{\mu}m$ within 30 days. After adding microbicides, the thickness of corrosion products film was only up to $48-106{\mu}m$ within 30 days, suggesting that SRB could induce biomineralization. Under-deposit corrosion morphology was uniform in the absence of microbicides while local corrosion was observed in the presence of microbicides.

• Journal of Korean Academy of Nursing
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• v.7 no.1
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• pp.88-98
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• 1977

This study was designed to identify a more effective method of nursing interview in gathering informations by comparing the two, the structured and unstructured methods. May through October, 1976, 40patients on psychiatric wards of Korea University Hospital and National Mental Hospital, Seoul, were sampled and interviewed on their admission/within one week of admission. Both methods were used simultaneously by different interviewers ; 48 hour interval were kept between the two approaches of interview. Contents of informations gathered were grouped according to the criteria developed by the researcher, frequency, percentile score and the means were scored, and the two methods were compared; the amount of information gathered, number of questions used, time spent and the general response towards the methodologies. Results of the study are summarized as follows ; 1. 1. 5 times as many informations were gathered through the structured interview. (1366 ; 849) 2. 68.32% of informations gathered through the unstructured interview and 42.46% of the structured interview revealed to be overlapping; through structured interview, more unique informations (57.54%) were gathered. 3. The average of 33.25 minutes were consumed for the structured interview while 95, 50 minutes for the unstructured. Much higher time consumption is revealed in the unstructured. 4. Majority of patients showed positive response towards both approaches of interview (90% each), however, interviewers responded to experience of certain degree of tension (stress) in the unstructured method (35%) 5. The average of 0.88 question were used to gather one information in the structured while 1.87questions for the unstructctured were used. 6. The average of 0.97 minutes were consumed to gather one information in the structured while 4.50minutes for the unstructured. 7. The average of 1.11 minutes were consumed for one question for the structured while 2.41 minutes for the unstructured. The results of the study revealed that the structured interview were more effective in gathering informations; a larger quantity of informations were gathered in shorter time. Recommendations for further in investigations are as follows ; 1. Comparative analysis of informations gathered through the two methods by experienced professional nurse- interviewers is recommended. 2. Comparative analysis of the quality of informations is recommended. 3. Comparative analysis of the interviewing process (interactions) in relation to the characteristics of patients'health problems is recommended.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.244-244
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• 2017

Recently, A study is actively underway to apply to various industries, which are one of the major changes in the key drivers of the industry 4.0.. The data generated by the ship include various indicators such as the fuel volume, engine power, ground speed, speed, speed, main engine rpm, DFOC, SFOC, and FOC. This paper analyzes the sensitivity of the Gathering data and analyzes the impact energy efficiency of the vessel operation by analyzing the influence among each parameter, using the mathematical models, you create an surrogate model using the math model, comparative analysis of actual measurement data and predictive results were analyzed. Through the use of big data analysis technology, it is possible to identify the sensitivity between the energy efficiency related variables of the ship, The possibility of utilization of fuel efficiency indicators using of the surrogate model is identified.