• 한국항해항만학회지
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• 제41권5호
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• pp.259-268
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• 2017

Formal Safety Assessment (FSA) has been mostly implemented on the hardware aspects of vessels. Although there are guidelines regarding human error FSAs, there have not been many assessments in such areas. To this end, this study seeks to use precedent studies for the safe operation of DP vessels, conducting an FSA regarding human error of DP LOP (Loss of Position) incidents. For this, the study referred to precedent studies for the frequency of DP LOP incidents caused by human errors, adding the severity of LOP incidents, and then applying them to the Bayesian network. As a result, the study was able to confirm that among DP LOP incidents caused by human errors, the drive-off from skill-based errors was 74.3% and the drive-off from unsafe supervision was 50.5%. Based on such results, RCOs (Risk Control Options) were devised through a brainstorming session with experts coming up with proposals including providing mandatory DPO training, installing DP simulator on the vessels, drawing up measures to understanding the procedures for safe operation of DP vessels. Moreover, it was found that mandatory DPO training is reasonable in terms of cost benefits and that while installing a DP simulator is not suitable in terms of cost benefits, it can significantly reduce risks when operating DP vessels.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.345-346
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• 2008

Most pedestrian-vehicle crashes involve frontal impacts, and the vehicle front structures are responsible for most pedestrian injuries. The vehicle bumper contacts the lower legs at first. The leading edge of the hood (bonnet) strikes the proximal upper leg and finally, the head and upper torso hit the top surface of the hood or windscreen. In essence, the pedestrian wraps around the front of the vehicle until pedestrian and vehicle are traveling at the same speed. Since the hood surface is made from sheet metal, it is a relatively compliant structure and does not pose a major risk for severe head trauma. However, serious head injury can occur when the head hits a region of the hood with stiff underlying structures such as engine components. The solution is to provide sufficient clearance between the hood and underlying structures for controlled deceleration of a pedestrian's head. However, considerations of aerodynamic design and styling can make it extremely difficult to alter a vehicle's front end geometry to provide more under-hood space. In this study, the safe hood will be developed by designing new conceptual inner panel in order to decrease the pedestrian's head injuries without changing hood outer geometry.

• 농촌지도와개발
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• 제28권1호
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• pp.1-12
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• 2021

This study aims to analyze the effects of the Agricultural Ecological Environment Program, the first agri-environmental policy in Korea. To this end, as Janghyeon in Boryeong City and Hwaam in Cheongyang County were set up as experimental group. And similar to these villages nearby, Hwangryong in Boryeong and Gideok in Cheongyang have been set up as the control group. It compared and analyzed the farms' level and structure of awareness. The main results of the study can be summarized as follows. First, the Agricultural Ecological Environment Program improved the awareness of safe agricultural product cultivation and agricultural ecological environment stabilize. However, the contribution to the formation of rural community has not been statistically significant. Second, it was found that the farms clearly distinguish and recognize the safe agricultural products cultivation, the agricultural ecological environment stabilize, and the formation of rural community. On the other hand, it was found that the control group that did not participate in the agricultural ecological and environmental program was confused on the recognition of three things or did not recognize them. To summarized, the future agri-environmental policy can be grafted onto regional development policy. So, the areas of agri-environmental policy should include both agriculture and rural. In addition, the scientific discipline and movement approach should be all used also in the method of approach.

• Journal of Platform Technology
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• 제10권4호
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• pp.82-90
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• 2022

최근 메타버스에 대한 사회적 관심이 높아짐에 따라 다양한 메타버스 플랫폼 및 서비스가 등장하고 있으며, 가상 세계의 수많은 가능성과 엄청난 잠재력을 보여주고 있다. 이러한 메타버스는 하나의 유형에만 국한되는 것이 아니라 경계를 허물며 가상융복합경제 형태의 서비스로 진화하며 발전하고 있다. 이에 따라 메타버스에서의 다양한 보안에 대한 이슈가 대두되고 있다. 메타버스는 가상 공간에서 모든 활동이 이루어지므로 프라이버시 침해나 가상 자산 탈취 또는 사기 등의 다양한 문제가 발생할 수 있다. 본 논문에서는 메타버스에서 안전한 서비스를 제공하기 위한 서비스 보안 모델을 제안하였다. 이를 위해 메타버스 프레임워크에서의 보안 위협을 분석하고, 위협을 방지하기 위한 보안 서비스 모델을 제안하였다. 제안 모델의 보안성을 평가하여 효과적으로 메타버스에서 안전한 서비스가 가능함을 보였다.

• 대한기계학회논문집A
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• 제39권4호
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• pp.361-367
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• 2015

논문에서는 인간과의 안전한 접촉이 가능한 내부형 연속체로봇에 대한 설계개념과 로봇 말단장치의 운동특성실험을 제시한다. 인간의 근육과 유사한 상극구동방식으로 작동하는 공압인공근육을 연속체로봇의 백본 및 구동장치로 사용하기 때문에, 외부환경과의 부드러운 접촉과 강한 접촉을 선택적으로 제어할 수 있는 로봇 관절에서의 가변강성이 가능하다. 그러나 내부형 연속체로봇은 백본소재의 굽힘운동을 예측하기 어렵기 때문에 로봇 말단장치에서의 자세를 추정하기 어렵다. 이를 해결하기 위해 3 축 가속도계와 3 축 자이로스코프를 이용한 칼만필터 방법을 제안하고 개발된 내부형 연속체 로봇의 자세추정에 적용하여 실제 실험을 통해서 제안된 방법의 효율성을 검증하였다.

• 한국ITS학회 논문지
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• 제10권6호
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• pp.1-14
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• 2011

미국 FHWA에서 개발한 Surrogate Safety Assessment Model(SSAM)은 상충이론을 기반으로 미시교통시뮬레이션모형(microscopic traffic simulation models)에서 생산된 개별 차량 경로 데이터를 이용하여 상충(conflict)의 발생을 분석하는 소프트웨어이다. 본 연구에서는 SSAM을 이용해 교통신호 제어 유형별 안전도를 비교하였다. 이를 위해 현장 조사를 기반으로 미시교통시뮬레이션모형을 구축한 후, 신호 제어 유형 별로 세 가지 신호운영 시나리오에 대하여 TTC, PET, DR, MaxS, DeltaS 등의 대리척도(surrogate measures)를 산출한 후, 직각충돌형(Crossing), 추돌형(Rear-end), 그리고 차로변경형(Lane Change) 상충 횟수를 추정하였다. 분석 결과 감응식 신호운영이 정주기식 신호운영보다 상충횟수가 많았으며, 그 중 추돌형 상충횟수가 다른 상충 유형에 비해 많은 것으로 분석되었다. 향후 SSAM 활용을 통해 교차로 및 다양한 교통 대안에 대한 안전도 평가가 신속하고 안전하게 수행될 수 있어 SSAM이 도로교통의 안전성 향상에 기여할 것으로 기대된다.

• Journal of Gastric Cancer
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• 제23권4호
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• pp.523-534
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• 2023

Purpose: Intra-abdominal infection is a common postoperative complication of laparoscopic pylorus-preserving gastrectomies (PPGs). Many studies have reported that intra-abdominal infectious complications after gastrectomy adversely affect patient survival outcomes. To prevent gastric fluid leakage into the abdominal cavity, we developed a novel anastomosis method in which the stomach lumen is not opened (termed the non-opened clean end-to-end anastomosis method [NoCEAM]) and evaluated its feasibility. Materials and Methods: Subsequent to lymphadenectomy, the oral and anal resection lines were sutured using an intraoperative endoscope. After closing the stomach circumferentially with clips, the specimen was rolled outward like a "donut." We resected the specimen circumferentially using a linear stapler, and anastomosis was completed simultaneously. We examined the feasibility of this procedure ex vivo, using three porcine stomachs, and in vivo, using one pig. Subsequently, we applied the procedure to 13 consecutive patients with middle-third early gastric cancer utilizing laparotomic, laparoscopic, and robotic PPG. Results: NoCEAM was completed in all porcine models and human cases. In the human cases, the mean operation time (±standard deviation) was 279±51 minutes, and mean blood loss volume was 22±45 mL. The mean number of linear staples used was 5.06±0.76. None of the patients had complications, and all were discharged on the eighth postoperative. The serum total protein, serum albumin, and hemoglobin levels did not change significantly after surgery. Conclusions: NoCEAM is feasible and safe for performing totally laparoscopic or robotic PPG. It may reduce postoperative complications, such as intra-abdominal infections.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3502-3507
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• 2013

스카이브릿지가 연결되는 건물에 강접합될 경우에는 비정형성이 크게 되어 지진하중에 매우 불리하게 거동할 수 있다. 따라서, 마찰진자베어링(FPS)이나 납고무베어링(LRB)와 같은 연결시스템을 사용하여 스카이브릿지와 구조물을 연결하게 된다. 이러한 연결시스템은 큰 지진하중이 발생하였을 때 스카이브릿지가 연결된 건물에서 분리되어 낙교하지 않도록 신중하게 설계되어야 한다. 본 논문에서는 수직방향 인장력에대해서 저항성이 없는 마찰진자감쇠기를 이용한 연결시스템을 설계하는 과정에서 반드시 검토해야할 사항을 분석하였다. 이를 위하여 실제 시공된 누리꿈 스퀘어를 예제구조물로 선택하였고 예상되는 지진하중이 가해졌을 때 스카이브릿지 연결시스템에서 발생하는 응답을 분석하여 낙교를 방지할 수 있는 설계 프로세스를 정립하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.397-401
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• 2008

Knowledge of dynamic characteristics of structural elements often can make difference between success and failure in the design of structure due to resonance effect. In this paper an analytical model of a cantilever beam having midpoint load is considered for structural optimization. This involves creating the geometry which allows parametric study of all design variables. For that purpose optimization of cantilever beam is elaborated in order to find the optimum geometry which minimizes its volume eventually for minimum weight using ANSYS. But such geometry could be obtained by different combinations of width and height, so that it may have the same cross sectional area yet different dynamic behavior. So for optimum safe design, besides minimum volume it should have minimum vibration as well. In order to predict vibration different dynamic analyses are performed simultaneously to solve the eigenvalues problem assuming no damping initially through MATLAB simulations using state space form for modal analysis, which identifies the resonant frequencies and mode shapes belonging to the lowest three modes of vibration. And next by introducing damping effects tip displacement, bending stress and the vertical reaction force at the fixed end is evaluated under some dynamic load of varying frequency, and finally it is discussed how resonance can be avoided for particular design. Investigation of results clearly shows that only structural analysis is not enough to predict the optimum values of dimension for safe design. Potentially this technique will meet maintenance and cost goals of many organizations particularly for the application where dynamic loading is invertible and helps a lot ensuring that the proposed design will be safe for both static and dynamic conditions.

• Architectural research
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• 제24권2호
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• pp.21-27
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• 2022

For the past decade, South Korea had experienced catastrophic building fires, which resulted in consider-ably high number of casualties. This motivated research to develop fire-safe wall assemblies. In this study Fire Risk Analysis (FRA) is conducted as part of the project designing phase to ensure fire safety of the final product. Traditional approach was to consider fire performance at the end of the designing stage, when PASS/FAIL fire test results are required to be submitted to the Authority Having Jurisdiction (AHJ). By applying a fire risk analysis to guide the designing phase, overall fire safety of a wall assembly can be achieved more systematically as conducting FRA allows designers to clearly identify elements that are more vulnerable to fire and simply replace them with other practical options. Severity of fire risk is determined by considering the fire hazards of a wall assembly such as the exterior layer, insulation, vertical connectivity, and external ignition sources (e.g., photovoltaic panels). Frequency of fire risk is assessed based on the factors affecting fire likelihood, which are air cavity and fire-stopping applied in the design, and random design changes occurring during on-site construction. Fire risk matrix is proposed based on these fire risk factors and efforts to reduce the fire risk level associated with the wall assembly are given by systematically assessing the fire risk factors identified from fire risk analysis. Current study demonstrates how fire risk analysis can be applied to develop fire-safe walls by reducing the relevant fire risks- both severity and frequency.