Keeping in mind that there are only limited social, economic and administrative resources for reducing marine casualties, the result of statistical survey showed the loopholes of safe maritime transport system, and rendered that most casualties occurred in coastal waters by human errors. When the IMO Marine Casualty Investigation Code was utilized to reveal any structural vulnerability of the international measures, IMO was required to expand its roles to enhance the interface between Liveware and Environment of SHEL model. So, several risk assessment models were studied and found that Maritime Safety Audit System of the Republic of Korea could be a good example of enhancing safe interface between navigators (Liveware) and the navigational circumstances (Environment). It could be dealt with at IMO level as a tool for applying at human error enforcing waters. International cooperative research for upgrading risk assessment modes should also be future terms of reference.

It is clearly understood that e-navigation is beneficial to prevent collision and grounding of ships. The purpose of this study is to define and present a future ship operation system under the e-navigation environment in order to provide clear direction for the design of Korean e-navigation system. The future ship operation system consists of shipboard navigational system, shore supporting system and maritime communication system. To achieve the objectives of this study, the ship operation system was discussed separately into SOLAS ships and non-SOLAS ships in this study. In SOLAS ships, mariners become a system manager, choosing system presets, interpreting system output, and monitoring vessel response. In small ships and fishing vessels, mariners may enjoy their navigation by using the automatic tracking of ship’s position on the portable electronic chart display. The improved bridge design, integrated and harmonized navigational system and single window reporting will reduce significantly the administrative and physical workload of mariners. Mariners can concentrate their attention more on navigational duty under the e-navigation environment. To build an effective Korean e-navigation system, the essential navigational functions and e-navigation services for small ships and fishing vessels must be identified and developed taking into account user needs.

Odor problems in urban areas have become a common cause of public complaints. In order to gain a better understanding of odor problems, we investigated the emission characteristics of odorants originating from manholes (n=22) and stormwater catch basins (n=48) (SCBs) around Wangsimni station in Seoul. To this end, concentrations of H2S and NH3 were measured after arbitrarily dividing the whole study area into five different districts. Our measurements were made to allow comparisons between three different criteria: (1) manholes vs. SCBs, (2) temporal variation between morning vs. afternoon, and (3) water content in the sewer system. The average concentration of H2S in manholes and SCB were 2.39 ppm and 0.81 ppm, respectively. In contrast, their NH3 counterparts were 1.86 ppm and 1.02 ppm, respectively. According to the contouring method made to identify spatial distribution characteristics, of odorants a relatively lowland site D was expected to work as a significant emission source in light of the transportation patterns of a sewer system. Moreover, higher concentrations of odorants were prevalent in the afternoon (as the prime time for commercial activities) relative to before noon. If concentration data are converted into odor intensity, H2S was the predominant component exerting controls on the odor pollution in these underground environments.

순환식 수막시스템의 적정 수온을 결정하는데 필요한 기초자료를 제공하기 위하여 딸기를 토경재배하고 있는 실험온실에서 외부온도, 수막용수의 수온 및 야간시간대에 따른 처리방식별 온실 내부 환경변화를 비교 분석하였다. 대조구는 무수막 온실이고, 처리구는 수온이 10oC, 15oC로 각각 설정된 순환식 수막온실로서 모두 무가온 및 추가적인 보온자재의 투입이 없는 상태를 말한다. 수막이 직접 살수되는 2중 비닐하우스는 폭 5.5m, 길이 55m이고, 분당 살수되는 평균 수막유량은 38.5~44.5L로 나타났다. 3가지 처리조건 모두에서 외부온도와 내부온도는 양의 선형관련성이 매우 높게 나타났으며 처리구 (10, 15oC)의 외부온도에 대한 상관성은 유사한 수준으로 분석되었다. 보온효과는 수온 15oC 처리구가 수온 10oC 처리구보다 1.3oC 정도 우수한 것으로 나타났다. 외부온도가 약 -8.1~8.6oC 범위에서 변화할 때, 처리조건 별 최저온도는 무처리구, 수온 10oC 처리구, 수온 15oC 처리구가 외부에 비해 각각 6.4, 11.0, 12.3oC 정도 높게 유지되는 것으로 나타났다. 평균 온도는 무처리구, 수온 10oC 처리구, 수온 15oC 처리구의 순으로 높아지고 온도변화폭은 오히려 작아지는 경향을 보였다. 외부 최저 온도가 -1.3oC, 평균온도가 1.5oC인 날은 수막시스템의 수온을 10oC로, 외부 최저온도가 -4.7oC, 평균온도가 -0.2oC 인 날은 수온을 15oC로 설정해도 온실의 목표온도(5oC) 유지가 가능한 것으로 나타났다. 처리조건별 야간시간대( 일몰 후, 자정, 일출 전, 일출 후)에 따른 온실 내부와 외부의 온도는 전반적으로 일몰직후가 가장 높고, 이후 서서히 감소하여 일출직전이 가장 낮아지는 경향을 보였다. 따라서 온실의 목표온도 유지를 위해서는 일출직전 시간대에 특히 집중적인 관리가 필요하며, 순환식 수막 시스템의 수온을 획일적으로 15oC 이상으로 결정하기 보다는 외부온도 변화, 야간시간대, 재배작물에 따라 다르게 결정하는 것이 타당한 것으로 판단된다.

To prevent safety hazards in dangerous working area, we have proposed an intelligent image analysis system. Six common patterns of safety violations of workers’ are defined and its motion detection algorithms are developed for alarm to CCTV　monitoring system. Developed algorithms are implemented at 195 dangerous areas such as chemical and gas treated room. The results of violated motion detection ratio by developed system shows 94.95% of true positive cases, and 0.21% of false positive cases from all 587,645 event cases in one month implementation period. In the period, it is observed that the number of safety rule violations and the following accidents are decreased.

Abalone (Haliotis discus hannai) is a shellfish that feeds on kelp and, as a product, it can often achieve a high market value. However, the dissolved oxygen (DO) levels in coastal waters in Korea have been negatively impacted by pollution from many anthropogenic sources. Herein, a computational fluid dynamics (CFD) software package was used to analyze the distribution of the DO concentration within an abalone containment structure. A finite volume approach was used to solve the Reynolds-averaged Navier–Stokes equations combined with a k–ε turbulence model to describe the flow. The distribution of DO was determined within the control volume domain, and the transport equations of the pollutants were interpreted using a CFD model. The CFD analysis revealed that more than 60% and 30% of the relative oxygen concentration in one and two containers, respectively, was maintained when the flow acts along the six sheets of polyethylene plates. Therefore, it is clear that the abalone plate shelters should be placed parallel to the flow.

This paper develops a LED fishing lamp mounting system which slides in and out a LED fishing lamp mounting rack according to fishing situation of a fishing boat. Sliding mechanism of the LED fishing lamp mounting system is realized with a rack and pinion. Components of the LED fishing lamp mounting system are modeled with finite elements. In addition, the LED fishing lamp mounting system is modeled with rigid bodies. A rigid body model of the LED fishing lamp mounting system is interfaced with finite element component models to develop a computational model of the LED fishing lamp mounting system. A simulation is performed with the developed computational model for dynamic stress analysis of the LED fishing lamp mounting system. A bouncing, rolling, and pitching motion which describe a very rough sea are used as input conditions for the simulation. Six cases are considered for the simulation based on the number of fishing lamp and the location of sliding rack.

To evaluate system reliability of a composite structure consisting of more than two structural members, it is necessary to identify that the members are connected to each others in parallel or in serial. Especially for parallel composite system, it is also necessary to confirm that mechanical properties of materials for the members are brittle or ductile. For parallel system of brittle materials, if one part fails, that part cannot resist load anymore and the whole load transfers to the other part. However, for parallel system of perfectly plastic materials, if one part fails, that part can maintain the amount of its maximum load capacity and the remaining load transfers to the other part. In this study, a methodology to determine reliability index for composite structures consisting of quasi-brittle materials. By assuming quasi-brittle materials as brittle or perfectly plastic materials, the upper and lower bounds of the reliability index can be determined. The reliability index for parallel system of quasi-brittle materials is then determined by interpolating the upper and lower bounds indices using ductility number extracted from stress-strain curves of quasi-brittle materials.

This study is aimed comparative analysis for business performance of land-based ezo abalone (Haliotis discus hannai) seed farms by standardizing cost structures by region and farming size. The result of survey on average farming incomes by region showed that farming incomes in Haenam and Jindo regions were much higher than those in other regions. Followed by Wando region, incomes in other regions were analyzed to be relatively lower. It is shown that farming incomes became higher as farm size increased. Farming incomes per unit size which were modified from farming incomes by region were highest in Jindo region, followed by East sea region, Wando and Haenam regions. Incomes in Jeju and Yeosu regions were analyzed to be relatively lower. Results on farming incomes per unit size (m2) showed that both farming incomes and profits became higher as size increased. It implies that a scale effectiveness might exist in case of land-based abalone culture system. Impacts of major factors on farming profits and returns on investment in abalone seed aquaculture are summarized as follow. First, only if the survival rate increased by 10% with improvement of component ratio, variable effects became largest. In variable effects of other factors, a variation in Jindo region was largest and on the other hand, a variation in Yeosu region was shown to be smallest.

Process capability indices (PCIs) have been widely used in manufacturing industries to provide a quantitative measure of process potential and performance to meet the specification limits on quality characteristics. The most of existing PCIs are concerned with a single variable. But, in many cases, people want to express a integrated PCI which includes a couple of sequential processes. In this paper, we analyzed the characteristics of system PCIs such as Cp(f), SCpk, SCpsk, Ctpsk(m) and SCpm(m).

A steady-state controllable M/G/1 queueing model operating under the {T:Min(T,N)} policy is considered where the {T:Min(T,N)} policy is defined as the next busy period will be initiated either after T time units elapsed from the end of the previous busy period if at least one customer arrives at the system during that time period, or after T time units elapsed without a customer’ arrival, the time instant when Nth customer arrives at the system or T time units elapsed with at least one customer arrives at the system whichever comes first. After deriving the necessary system characteristics including the expected number of customers in the system, the expected length of busy period and so on, the total expected cost function per unit time for the system operation is constructed to determine the optimal operating policy. To do so, the cost elements associated with such system characteristics including the customers’ waiting cost in the system and the server’s removal and activating cost are defined. Then, procedures to determine the optimal values of the decision variables included in the operating policy are provided based on minimizing the total expected cost function per unit time to operate the queueing system under considerations.

A CCTV inspection method has been widely used to assess sewer condition and performance, but Korea lacks a proper decision support system for prioritizing sewer repair and rehabilitation (R&R). The objective of this paper is to introduce the results that we have developed in the Sewer Condition Assessment and Rehabilitation Decision-making (SCARD) Program using MS-EXCEL. The SCARD-Program is based on a standardized defect score for sewer structural and hydraulic assessment. Priorities are ranked based on risk scores, which are calculated by multiplying the sewer severity scores by the environmental impacts. This program is composed of three parts, which are decision-making for sewer condition and performance assessment, decision-making for sewer R&R priority assessment, and decision-making for optimal budget allocation. The SCARD-Program is useful for decision-makers, as it enables them to assess the sewer condition and to prioritize sewer R&R within the limited annual budget. In the future, this program logic will applied to the GIS-based sewer asset management system in local governments.

When designing Water Distribution System (WDS), determination of life cycle for WDS needs to be preceded. And designer should conduct comprehensive design including maintenance and management strategies based on the determined life cycle. However, there are only a few studies carried out until now, and criteria to determine life cycle of WDS are insufficient. Therefore, methodology to determine life cycle of WDS is introduced in this study by using Life Cycle Energy Analysis (LCEA). LCEA adapts energy as an environmental impact criterion and calculates all required energy through the whole life cycle. The model is build up based on the LCEA methodology and model itself can simulate the aging and breakage of pipes through the target life cycle. In addition the hydraulic analysis program EPANET2.0 is linked to developed model to analyze hydraulic factors. Developed model is applied to two WDSs which are A WDS and B WDS. Model runs for 1yr to maximum 100yr target life cycle for both WDSs to check the energy tendency as well as to determine optimal life cycle. Results show that 40yr and 54yr as optimal life cycle for each WDS, and tendency shows the effective energy is keep changing according to the target life cycle. Introduced methodology is expected to use as an alternative option for determining life cycle of WDS.

This study was carried out to analyze water suspension in the water supply system through fault tree analysis. And quantitative factors was evaluated to minimize water suspension. Consequently the aim of this study is to build optimal planning by analyzing scenarios for water suspension.Accordingly the fault tree model makes it possible to estimate risks for water suspension, current risks is 92.23 m3/day. The result of scenario analysis by pipe replacement, risks for water suspension was reduced 7.02 m3/day when replacing WD4 pipe. As a result of scenario analysis by water district connections, the amount of risk reduction is maximized when it is connecting to network pipe of D Zone. Therefore, connecting to network pipe for D Zone would be optimal to reduce risk for water suspension.

본 논문에서는 액화천연가스 운송을 위해 사용되는 맴브레인형 Mark Ⅲ 화물창 시스템의 주요 구조물인, 방열 판 구조물의 파손 강도 평가를 수행한 내용을 다루고 있다. Mark Ⅲ 방열 판 구조물을 복합적층 구조물로 고려하였으며 상용화된 범용 유한요소 프로그램인 MSC사의 PATRAN과 MARC를 사용하여 Mark Ⅲ 방열 판 구조물의 유한요소 모델을 개발하였다. 특히, 액화천연가스 화물의 특성으로 인해 Mark Ⅲ 방열 판 구조물이 접하는 상온에서 극저온에 이르는 광범위한 온도분포에 따른 재료 물성치 변화를 유한요소 모델에 포함하였다. 이 유한요소 모델을 기반으로 파손 강도 평가 절차가 확립되었으며, 이 때 Mark Ⅲ 방열 판 구조물의 파손 발생 여부를 판단하기 위해 Hashin, Hill, Hoffman, maximum stress, 그리고 Tsai-Wu와 같은 이방성 파손 기준들을 사용하였다. Mark Ⅲ 방열 판 구조물의 전반적인 구조적 거동을 이해하였으며 이후 초기 파손 영역에서 강도 평가를 수행하여 파손이 발생되었을 때의 위치와 하중 등을 알 수 있었다.

Vehicle crash analysis a lot of time and manpower in preprocessing for analysis rather than analysis in analytical studies of the situation that is being committed. In this studies involving conflict with an existing automation system of the body is mainly optimized for a particular field, and researchers think that is an inconvenience that can be used in stone until a comprehensive analysis of the bodywork of each study. Therefore, it is very important to development of automotive system for vehicle crash analysis, the research related studies were carried out. In this study, vehicle crash analysis is performed against that can be used for multiple and effectively utilized by system based meshing in an aim to reduce the time and resource that by developing an automotive system. The results of the study, it was possible to construct an automated system the more time consuming mesh generation for vehicle crash analysis.

이 연구는 파각란 선별기 도입을 비용 편익분석 목적으로 수행되었다. 계란 파각란 선별기를 도입할 때의 총수입과 총비용 평가액의 추정결과는 다음과 같다. 총비용의 경우 구입가격, 고정비용 및 유동비용의 합계로 나타내었고, 할인율에 따라 5%, 10%일 때 각각 232,904천원과 242,904천원으로 산정되었다. 계란 파각란 선별기 평가액은 할인율에 따라 228,543천원(할인율 5%인 경우)과 218,543천원(할인율 10%인 경우)으로 추정되었다(Table 6). 파각란 선별기 기술가치에 대한 평가는 B/C비율, 순현재가치(NPV), 내부수익율(IRR)의 값으로 판단되었고, 내부수익율 IRR의 값은 가정했던 할인율보다 훨씬 높게 나타났고, 순현재가치도 0보다 큰 값으로 나타났으며, B/C비율도 1.0 이상으로 나타나 경제적 타당성을 가지는 것으로 판단되었다(Table 7).

In this study, Intersecting Tensegrity System that is integrated solid compression members with tension members was presented. This system is set up by connecting upper and lower compression members of pyramid shape with exterior tension members. In this system, the solid compression members are intersected each other and connected by a tension member in the center. This system is a variation of Tensegrity system, has a improved feature that the system is able to induce prestresses in all of tension members easily by adjusting the distance of a tension member in the center. The proposed system was studied by modeling, and the structural behavior of the system was investigated by mechanical analysis of the model. Furthermore, the features of the structural behavior variations was investigated when the composition elements(total height, size of surface, intersection length, etc.) are changed variously. It was also showed that the system is able to be used as a temporary space structure system with a membrane roof of inverse conical shape.

기존의 기술 진화 경로 연구는 주로 거시적 동향 분석 수준에서 이루어져 왔으 며 포괄적인 기술정책 방향 수립에는 시사점이 있었으나, 기업 기술 및 특허전략에는 활용 가치가 낮았다. 2000년대부터 논문 및 특허 등의 데이터를 활용해 미시적인 기술의 진화 경 로를 분석하고, 기업 기술전략에 적용하려는 연구가 증가하고 있다. 그러나 대부분 과거 진 화 경로의 서술에 그치고 있으며 기술의 진화 또는 파생-융합 등의 변화에 대한 분석은 전문 가의 정성적 판단에 상당부분 의존하고 있다. 본 연구에서는 특허 인용 네트워크를 구축해 미시적 기술의 진화 경로를 도출하고, 기술의 진화와 파생을 동적 기술트리를 통해 분석하는 방법론을 제시한다. 동적 기술트리 분석은 기술의 핵심요소를 체계화하고, 신기술 요소의 신 규성과 확장성을 평가해 차세대 기술진화와 파생에 대한 정량적 판단을 가능하게 한다. 이를 통해 차세대 신기술과 파생기술에 대하여 파악, 평가, 비교하고 나아가 예측의 토대를 구축 한 것이 본 연구의 의의이다. 본 연구의 결과는 기술 및 특허전략과 포트폴리오 구축의 신뢰성을 높일 수 있는 좋은 도구가 될 것이다. 본 연구에서 제안한 방법론을 이용하여 최근 전력 산업에서 기존 교류 송전의 대안으로 주목을 받고 있는 초고압 직류송전 시스템 기술을 대상 으로 실증분석을 수행하였다.