• 한국인터넷방송통신학회논문지
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• 제18권6호
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• pp.121-126
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• 2018

IEEE 802.1 TSN(Time Sensitive Network) TG(Task Group)는 이더넷을 기반으로 지연시간 보장 및 패킷 무손실 서비스를 제공하는 기술의 표준화를 진행 중이다. 본 연구는 다양한 TSN 기술 중 패킷 포워딩 기술에 주목한다. TSN의 포워딩 기술은 크게 동기형과 비동기형으로 구분할 수 있다. 동기형은 시간 동기화 기술을 바탕으로 정해진 시간 구간을 정해진 class에 할당하는 기술이지만 대규모 네트워크에서 사용하기 어렵다. 비동기 기술은 트래픽 regulation과 class 별 스케줄링을 바탕으로 지연시간 보장을 약속하지만 필요 이상으로 복잡한 구조를 가진다. 본 논문에서는 비동기형 TSN 네트워크 구조를 보다 간단히 만들면서도 지연시간을 보장하는 방안을 제시하였다. 이를 통해 플로우의 상태를 저장하여 regulation 결정에 사용해야 하는 복잡성을 배제할 수 있었다. 이러한 간단한 구조에도 불구하고 높은 우선순위 트래픽의 최대 패킷길이를 일정 수준 이하로 제한하면 TSN의 요구사항을 만족시킴을 보였다.

• 한국산업보건학회지
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• 제29권2호
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• pp.217-225
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• 2019

Objectives: The aim of this study is to evaluate the quality management systems of domestic asbestos survey and monitoring service providers and the relationships with the number of licenses or designations and sales performances. Methods: Data on quality management systems were collected by assessors who were assigned by the Korea Occupational Safety and Health Agency(KOSHA) during a pilot evaluation program for designated asbestos survey and monitoring service providers in 2016 using evaluation criteria developed by KOSHA. Basic characteristics, evaluated scores, and sales performance were gathered and statistically analyzed. Results: The median and arithmetic mean of the total scores were 0.64 and 0.66. Evaluation fields that scored highly with the highest percentages were sales performance, installation and availability of equipment, compliance with the mandatory minimum number of airborne samples, laboratory independence, and results of proficiency analytical testing, in that order. Evaluation fields that received low marks with the highest percentages were the training of personnel, blank field samples, calibration of flow rates, preliminary check and visual inspection of the work area prior to the clearance test, and review and approval of final reports, in that order. Comparison of normalized scores between service providers registered for asbestos and other tasks and those designated for only asbestos showed significant differences in their evaluated scores. Sales performance did not show a positive correlation with evaluated scores. Conclusions: The quality management systems of domestic asbestos survey and monitoring service providers were poor. High scores were recorded mostly in evaluation fields related to regulatory requirements. Low scores were recorded mostly in evaluation fields related to documentation and recordkeeping. Considering the low influence of quality on sales performance, the government needs to evaluate the quality management of asbestos survey and monitoring service providers and provide the results to public in order to address their low levels of quality management.

• Nuclear Engineering and Technology
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• 제51권6호
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• pp.1540-1553
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• 2019

A nuclear power plant (NPP) is a highly complex system-of-systems as manifested through its internal systems interdependence. The negative impact of such interdependence was demonstrated through the 2011 Fukushima Daiichi nuclear disaster. As such, there is a critical need for new strategies to overcome the limitations of current risk assessment techniques (e.g. the use of static event and fault tree schemes), particularly through simulation of the nonlinear dynamic feedback mechanisms between the different NPP systems/components. As the first and key step towards developing an integrated NPP dynamic probabilistic risk assessment platform that can account for such feedback mechanisms, the current study adopts a system dynamics simulation approach to model the thermal dynamic processes in: the reactor core; the secondary coolant system; and the pressurized water reactor. The reactor core and secondary coolant system parameters used to develop system dynamics models are based on those of the Palo Verde Nuclear Generating Station. These three system dynamics models are subsequently validated, using results from published work, under different system perturbations including the change in reactivity, the steam valve coefficient, the primary coolant flow, and others. Moving forward, the developed system dynamics models can be integrated with other interacting processes within a NPP to form the basis of a dynamic system-level (systemic) risk assessment tool.

• 대한치과보철학회지
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• 제57권1호
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• pp.57-65
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• 2019

Computer guided implant surgery와 computer-aided design/computer-aided manufacturing, computer guided implant surgery (CAD/CAM) 기술의 발전은 수복 기반 임플란트 치료의 완성도를 한층 더 높였으며, 3D printing을 통한 국소의치의 제작도 빈도가 늘고 있다. 본 증례는 디지털 치의학의 작업 흐름을 따라서 콘빔컴퓨터단층촬영을 통한 치료 계획 수립 및 수술용 스텐트의 제작과 그를 바탕으로 한 임플란트 식립을 하였으며, 맞춤 지대주와 보철물을 제작하였다. 그 후 전자 서베잉과 3D printing을 통한 국소의치 금속 구조물 및 최종적으로 지르코니아 온레이의 제작을 통해 전악 수복을 완성하여 기능과 심미적으로 만족스러운 결과를 얻을 수 있었다.

• 인터넷정보학회논문지
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• 제19권6호
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• pp.83-89
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• 2018

워크플로우 프로세스 인텔리전스와 시스템에서 워크플로우 프로세스 마이닝 및 분석 문제가 중요해지고 있다. 워크플로우 프로세스 인텔리전스의 품질을 향상시키기 위해서는 워크플로우 프로세스 마이닝 및 분석을 수행할 때, 워크플로우 실행 이벤트 로그를 저장하는 효율적이고 효과적인 데이터 센터가 필수적이다. 본 논문에서는 워크플로우 이벤트 로그 데이터 센터를 효율적으로 구성하고 XES 형식으로 워크플로우 프로세스 실행 이벤트 로그를 효과적으로 저장하기 위한 3차원 프로세스 기반 데이터 큐브를 제안한다. 이의 검증 단계로서, 프로세스 기반 데이터 큐브가 워크플로우 프로세스 패턴과 해당 워크플로우 프로세스 실행 이벤트 내역에서 실행 비율 및 업무전달관계와 같은 분석적 지식을 발견하는데 얼마나 적합한지를 보여주기 위해 프로세스 마이닝 실행 예제를 제시한다. 결과적으로, 프로세스 기반 데이터 큐브와 이를 활용한 프로세스 마이닝 시스템의 구현을 통해, 워크플로우 프로세스의 기본적 제어흐름 패턴을 성공적으로 발견할 수 있음을 확인했다.

• 한국컴퓨터정보학회논문지
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• 제26권6호
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• pp.167-172
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• 2021

이 연구의 목적은 언론에서 바라보는 객관적이고 거시적인 시선인 빅데이터 분석을 통해 청원경찰제도의 발전적 방향과 학문적 시사점을 제시하는데 목적을 두고 있다. 연구방법은 '청원경찰'에 대한 분석 및 키워드 트렌드와 연관성이 높은 키워드를 시각해 보여주는 연관어 분석을 실시하였다. 또한 1990년대, 2000년대, 2010년대로 구분하고 해당하는 기간의 매년 관련 기사 건수를 도출하여 흐름을 파악하였다. 연구결과에 따른 청원경찰의 언론보도 인식은 청원경찰의 채용, 관련 사건·사고에 대한 것으로 긍정적인 청원경찰의 채용에 대한 관심과 부정적인 청원경찰 관련 사건·사고에 대한 이미지가 공존한다는 것을 볼 수 있다. 하지만 결과적으로 청원경찰에 대한 필요성과 수요는 증가하고 있으며, 이를 통해 청원경찰을 국가의 안전을 책임지고 사회질서유지를 위한 한 축으로써의 윤리적 책임과 안전을 책임지는 역할에 대한 고민하고 청원경찰의 업무에 임해야 할 것이다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권5호
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• pp.9-19
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• 2021

This study evaluated the feasibility of combined use of physical separation and soil washing to remediate heavy metals (Pb and Cu) contaminated soil in a military shooting range. The soils were classified into two types based on the level of heavy metal concentrations: a higher contaminated soil (HCS) with Pb and Cu concentrations of 6,243 mg/kg and 407 mg/kg, respectively, and a lower contaminated soil (LCS) with their concentrations of 1,658 mg/kg and 232 mg/kg. Pb level in both soils exceeded the regulatory limit (700 mg/kg), and its concentration generally increased with decreasing soil particle size. However, in some cases, Pb concentrations increased with increasing soil particle size, presumably due to the presence of residues of bullets in the soil matrix. As a pretreatment step, a shaking table was used for physical separation of soil to remove bullet residues while fractionating the contaminated soils into different sizes. The most effective separation and fractionation were achieved at vibration velocity of 296 rpm/min, the table slope of 7.0°, and the separating water flow rate of 23 L/min. The efficiency of ensuing soil washing process for LCS was maximized by using 0.5% HCl with the soil:washing solution mixing ratio of 1:3 for 1 hr treatment. On the contrary, HCS was most effectively remediated by using 1.0% HCl with the same soil:solution mixing ratio for 3 hr. This work demonstrated that the combined use of physical separation and soil washing could be a viable option to remediate soils highly contaminated with heavy metals.

• KEPCO Journal on Electric Power and Energy
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• 제5권3호
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• pp.189-195
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• 2019

논문에서는 상용급 가스터빈을 대상으로 해서 셰일가스를 연료로 공급할 때 유동 및 연소특성을 3-D 수치해석적 방법으로 구하였다. 이 때, Standard k-e 난류모델, 2단 메탄산화반응, Finite rate/Eddy dissipation 반응모델, DTRM 복사모델이 사용되었고, 기준조건(도시가스, PR 0.07)에서 출구 측에서 형성되는 온도는 이전 문헌 값과 비슷한 값을 보였다. 위 모델을 바탕으로 해서 연료조건으로 기존의 도시가스 외에 세 가지 셰일가스 조건(도시가스 대비 열량기준 80%, 90%, 105%)을 선정하였고, 각 연료조건에 대하여 세 가지 연료분사조건(PR=0.7, 0.9, 0.11)에 대한 해석을 수행하였다. 해석결과, 모든 셰일가스 연료공급 조건에 대하여 도시가스 대비 온도 혹은 NOx 측면에서 연소안정화를 만족하였다. 또한 모든 조건에 대해서 PR이 증가할수록 출구측 평균온도는 일정했지만 NOx량은 증가하였다. 이는 파일럿비가 증가할수록 상대적으로 확산연소가 증가했기 때문이다.

• 대한건축학회논문집:계획계
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• 제34권1호
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• pp.83-94
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• 2018

UNESCO has continued to work in Africa, especially in the six southern sub-Saharan countries, and Asia, where international cooperation is needed. The CLC (Rwanda Community Learning Center) covered in this study aims to create a regional learning center in Rwanda and to recover local communities and provide learning environment. During the course of this study, we conducted field trips for actual planning and reviewed the current state of educational and cultural facilities that recently opened and are operated, and found implications. In consultation with the Rwandan Educational Commission, the site for CLC was decided, the building was designed, and the construction is about to start. The results of this study are as follows. First, in addition to the efforts of the activists in the village, which can be considered the smallest unit of a local community, the approach for establishing an architectural space and active education and community environment can be evaluated as a result of experimental efforts. Second, we can pay attention to the attempts to realize local communities. The bridge business is based on the multi-purposes such as early childhood education, technical education for adults, and community restoration of local residents and it reflects space and program plans for this purposes. It also reflects detailed plans such as differentiating the flow planning depending on users' time of use. Third, we can explain the characteristics of architectural planning considering local characteristics such as active use of local materials. Due to the characteristics of a developing country, there were significant considerations on maintenance, and to this end, the plan included plans for the environment and use of materials that are easily maintained. In addition, the participation of local residents in the process of establishment was suggested as a possibility to serve an educational role.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권6호
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• pp.2168-2187
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• 2021

The smart grid replaces the traditional power structure with information inventiveness that contributes to a new physical structure. In such a field, malicious information injection can potentially lead to extreme results. Incorrect, FDI attacks will never be identified by typical residual techniques for false data identification. Most of the work on the detection of FDI attacks is based on the linearized power system model DC and does not detect attacks from the AC model. Also, the overwhelming majority of current FDIA recognition approaches focus on FDIA, whilst significant injection location data cannot be achieved. Building on the continuous developments in deep learning, we propose a Deep Learning based Locational Detection technique to continuously recognize the specific areas of FDIA. In the development area solver gap happiness is a False Data Detector (FDD) that incorporates a Convolutional Neural Network (CNN). The FDD is established enough to catch the fake information. As a multi-label classifier, the following CNN is utilized to evaluate the irregularity and cooccurrence dependency of power flow calculations due to the possible attacks. There are no earlier statistical assumptions in the architecture proposed, as they are "model-free." It is also "cost-accommodating" since it does not alter the current FDD framework and it is only several microseconds on a household computer during the identification procedure. We have shown that ANN-MLP, SVM-RBF, and CNN can conduct locational detection under different noise and attack circumstances through broad experience in IEEE 14, 30, 57, and 118 bus systems. Moreover, the multi-name classification method used successfully improves the precision of the present identification.