• Journal of Digital Contents Society
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• v.18 no.4
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• pp.739-745
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• 2017

This paper presents and discusses an implementation of the GPU shifted sorting method to find approximate k nearest neighbors which executes within "warp", the minimum execution unit in GPU parallel architecture. Also, this paper presents the comparison results with other two common nearest neighbor searching methods, GPU-based kd-tree and ANN (Approximate Nearest Neighbor) library. The proposed implementation focuses on the cases when k is small, i.e. 2, 4, 8, and 16, which are handled efficiently within warp to consider it is very common for applications to handle small k's. Also, this paper discusses optimization ways to implementation by improving memory management in a loop for the CUB open library and adopting CUDA commands which are supported by GPU hardware. The proposed implementation shows more than 16-fold speed-up against GPU-based other methods in the tests, implying that the improvement would become higher for more larger input data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.255-266
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• 2011

In order to evaluate the environmental load occurring from the whole life cycle of a facility, LCA (Life Cycle Assessment) adopted by ISO is not only applied as an individual product but rather a complicated system involving buildings and/or infrastructure in a wide range of scope. The introducing of LCA to a wastewater reuse facility will assist to understand not only the treatment of water contaminants but also the overall system related to the interaction of involved, potential issues. This research implemented LCA for the establishment of the wastewater reuse facility. The results show that a fresh water aquatic Eco-toxicological Impact (88.3%) is the largest environment concern and the maintenance & operation phase has the most impact on the environment utilizing life cycle for the wastewater reuse facility. The civil works and chemical treatments in the maintenance & operation phase led to the biggest environmental impact. The results of this research can provide pertinent data of investigating opportunities for environmental improvement not limited to public officers regulating environmental policies, and could be used to make decisions for an environmentally sound and sustainable design in the initial phase of construction.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.396-402
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• 2014

The measurement of air-borne noise in a naval ship is a crucial element. Because the noise in a naval ship interferes with a communication between crews and finally it causes to reduce the combat power. Thus, most of newly built ships have to satisfy the criteria of air-borne noise in the stage of delivery of a naval ship. In order to evaluate success or failure of criteria, uncertainty of the measurement should be considered. This study introduces the test method for the measurement of the air-borne noise in a naval ship and is concerned with the evaluation of uncertainty. The uncertainty results which was from the measurement of air-borne noise in 7 naval ships newly built satisfy the error tolerance(2dB). Therefore, it is need to reduce the error tolerance for the reliable measurement result.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.181-190
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• 2017

Recently, safety accidents of daily necessities such as humidifier disinfectant, mobile phones, and infant diapers, have occurred frequently. To protect consumers from these accidents, product safety management is required, and a product risk assessment tool is needed to evaluate the degree of safety of the product. In this paper, we have constructed RAS, which is a system that can evaluate product risk based on injury information of product accident in Korea Consumer Agency. RAS consists of an injury information analysis system for analyzing accident-related information and a risk assessment system for assessing risk using information derived from the system. The Bayesian network - based probabilistic method is applied to reflect the causal relationships that affect product risk in the risk assessment process. We used RAS to evaluate 33 children's products and compared them with the results of EU RAPEX RAG. Subsequent tasks include reducing the subjectivity of the input of the accident impact scale, and linking the above two systems.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.325-325
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• 2011

자연과 함께하는 하천복원 기술개발(Ecoriver21) 연구단에서 진행 중인 홍수터 수목관리 기술 개발 과제에서는 국내하천 흐름저항 산정기법을 개발하기 위해 2006년부터 2009년까지 총 27개 시험하천의 실측자료를 이용한 조도계수를 산정하였다. 2010년에는 18개 시험하천을 추가로 운영하여 최종적으로 총 45개 하천의 조도계수를 산정하고자 한다. 조도계수 계산에 필요한 자료는 모두 현장에서 직접 측정하였으며 이를 위해 넓은 범위의 수위자료를 획득할 수 있는 홍수기 이전에 수위계를 설치하였고, 유량 측정, 하천 단면 측량, 하상재료 입경분석 등을 통하여 유량 변화에 따른 조도계수 분석, 하상재료 크기별 조도계수 변화 분석, 조도계수 경년변화 분석 등의 연구를 진행하였다. 분석 결과 대부분의 하천은 유량이 증가함에 따라 조도계수가 감소하는 경향을 보였고 특정한 유량 범위에서 수렴하였다. 유량에 따른 조도계수 변화 폭은 하상재료의 입경 크기가 클수록 심하였다. 산지 거석하천인 내린천 왕성동 지점의 경우 0이 287.8 mm로 조사 지점 중 하상재료의 크기와 유량에 따른 조도계수 변화 폭, 수렴되는 조도계수 값이 가장 컸다. 하상재료 입경 크기 $D_{50}$을 기준으로 2 mm이하인 모래하천의 경우에는 유량이 증가함에 따라 조도계수가 감소하다가 고유량에서 다시 증가하는 경향을 보였다. 조도계수 경년변화를 분석한 평창강 방림 지점과 만경강 고산 지점의 결과는 비교적 큰 차이를 나타내지 않았고, 한강 본류의 배수영향을 받는 옥동천 옥동, 법천천 법천 지점의 경우 배수 상황 발생 시 다른 지점과 달리 상당히 복잡한 양상을 나타내었다. 본 연구에서는 지금까지 진행된 국내하천의 조도계수 분석 자료를 종합하여 조도계수 자료집을 발간할 계획이며, 조도계수 자료집에는 각 지점의 수위 및 유량 실측자료, 하상재료 입경 크기, 지점 특성, 사진 자료 등이 포함될 예정이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.12
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• pp.2287-2297
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• 2007

The proposed ANIDS(Advanced Network Intrusion Detection System) which is network-based IDS using Association Rule Mining, collects the packets on the network, analyze the associations of the packets, generates the pattern graph by using the highly associated packets using Association Rule Mining, and detects the intrusion by using the generated pattern graph. ANIDS consists of PMM(Packet Management Module) collecting and managing packets, PGGM(Pattern Graph Generate Module) generating pattern graphs, and IDM(Intrusion Detection Module) detecting intrusions. Specially, PGGM finds the candidate packets of Association Rule large than $Sup_{min}$ using Apriori algorithm, measures the Confidence of Association Rule, and generates pattern graph of association rules large than $Conf_{min}$. ANIDS reduces the false positive by using pattern graph even before finalizing the new pattern graph, the pattern graph which is being generated is compared with the existing one stored in DB. If they are the same, we can estimate it is an intrusion. Therefore, this paper can reduce the speed of intrusion detection and the false positive and increase the detection ratio of intrusion.

• Korean Security Journal
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• no.56
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• pp.55-81
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• 2018

The purpose of this study is to find significant activities in human resource management (HRM) to solve growing-pains caused by the rapid external growth in private security business. To this end, we applied the HRM factors suggested by the National Job Capability Standard (NCS) to the private security and investigated the relative importance using the Analytic Hierarchy Process (AHP). The results were as follows. First, the importance of 4 HRM criteria in the private security was ranked in order of recruitment, operation, benefit, and retirement. Particularly, the relative importance of recruitment reached 63.8%. Second, the composite importance was calculated by dividing the 4 HRM criteria into 14 capability sub-criteria and 46 capability alternatives. As a result, personnel planning and hiring at the recruitment turned out as the areas that needed the most improvement. In addition, the operating and planning of education involved in the highest rank, 8th and 10th respectively. Based on these results, we suggested critical HRM factors for developing the private security business as well as proposed research directions and methods for further studies.

• Journal of Korea Water Resources Association
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• v.52 no.11
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• pp.941-946
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• 2019

A wildfire could significantly alter the local hydrological regime, depending on the area and severity, and thus it is critical to understand its effect and feedback using data and simulation. For the wildfire in Gangwon-do on April 4-5, 2019, South Korea, we retrieved the Normalized-Burned Ratio (NBR) index using remote-sensing data (500-m 8-day MODIS surface reflectance data), and detect the damaged-area based on the difference in the NBR (dNBR) before and after the fire. The damaged area was $29.50km^2$ in total, taking up 1.00-6.19% of five catchments. We then used remote-sensing data (500-m 8-day MODIS evapotranspiration data) and estimated that annual evapotranspiration (AET) would decrease as 0.05-1.56% over the five catchments, as compared to the pre-fire AET (2004-2018). This study highlights the importance of improving our understanding about the impact of wildfire on the local hydrological cycle.

• Journal of Society of Occupational Therapy for the Aged and Dementia
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• v.12 no.2
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• pp.13-18
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• 2018

Objective : The purpose of this study is to confirm the basis for the effectiveness of sleep intervention for dementia progression. Method : PsycINFO, CINAHL, MEDLINE, PubMed, Science Direct, PEDro, Cochrane library was used to search for published papers from 2000 to 2017 using dementia, sleep, and randomized controlled trials (RCTs). Based on the results, author analyzed the papers that met the selection criteria. Result : Finally, five papers were selected. Among them, there were four papers showing that the effectiveness of the sleep intervention was not proven to be one. Conclusion : The results of this study can provide a basis for the sleep intervention effect of dementia patients. A program to actively intervene to prevent patients' behavior control and disease progression through solving sleep problems of dementia patients is needed.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1123-1130
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• 2020

This study aims to classify the severity in car crashes using five classification learning models. The dataset used in this study contains 21,013 vehicle crashes, obtained from Korea Expressway Corporation, between the year of 2015-2017 and the LightGBM(Light Gradient Boosting Model) performed well with the highest accuracy. LightGBM, the number of involved vehicles, type of accident, incident location, incident lane type, types of accidents, types of vehicles involved in accidents were shown as priority factors. Based on the results of this model, the establishment of a management strategy for response of highway traffic accident should be presented through a consistent prediction process of accident severity level. This study identifies applicability of Machine Learning Models for Predicting of the Severity of Car Traffic Accidents on a Highway and suggests that various machine learning techniques based on big data that can be used in the future.