In this article, to solve the problems about obsolescence of parts and unable to driving turret when internal components are failure, the DC-DC boost converter in the gun/turret drive system of mobile weapon was improved. The power converting circuit in converter is changed by applying the latest components, and the control circuit is changed from analog to digital. Also, the power converting circuits were modularized in three parallel so that it could be driven even when some components failed. The improved DC-DC boost converter secured stability such as converting to voltage in a linear manner in the entire section from the start of boosting to the end. Also, through the modular configuration, turret driving system can operates when some components failed.
해양 조난사고가 발생하면 해양경찰은 수색계획을 수립하기 위하여 조난자의 수와 신원을 파악하는 등 사고 현황을 조사한다. 선장은 출항 시 선원과 승객의 신분을 포함한 명부를 첨부하여 관할기관에 신고서를 제출하도록 명시되어 있지만 승선자들이 수기로 승 선자명부를 작성하면서 대기 시간이 길어지고 조난사고 발생 시 이러한 내용을 즉시 파악하기 어렵다. 승선 신청을 편리하게 할 수 있도 록 해양수산부에서 앱을 개발하였지만, 활성화되고 있지 않아 본 연구에서 이를 개선하는 방안을 제안하였다. 모바일 승선신고 제도를 활 성화하여 조난사고 시 조난자의 초기 위치와 조난시각을 신속히 확보하고 조난신고 접수 사실을 문자로 통보하여 조난자에게 심적 안도 감을 제공할 수 있다. 더불어 이 정보 이용을 통해 해양경찰을 포함하여 주변에 있는 민간 선박과 함께하는 민관협력 형태로 신속히 구조 할 수 있는 효과를 기대할 수 있다.
Path planning is necessary for mobile robots to perform precise and rapid tasks. A collision avoidance function must be included so that the robot can move safely during work, and it must be able to create an optimal path to reduce work execution time and save energy. In this paper, we propose a smart route generation algorithm that searches for global route with an algorithm that can speed up route search and integrates the TEB algorithm that can search for regional optimum routes in real time according to the situation. The performance of the proposed algorithm was verified through actual driving experiments of mobile robots.
최근 10년간 국내에서 발생한 해양사고현황에 따르면, 총톤수 10톤 미만의 소형어선이 차지하는 비중은 전체 해양사고 중 47.51%로 높게 확인되었다. 또한 해양사고의 증가추세 역시 다른 선종/크기(총톤수)에 비해 매우 가파르게 증가하고 있어 이에 대한 대책마련이 시급한 실정이다. 한국해양교통안전공단에서는 소형어선의 선박검사제도 개선방안으로 자체검사제도의 도입을 제안한 바 있으며, 해양수산부에서는 최근 비대면 검사방법의 도입을 위해 ‘원격방식에 의한 선박검사 지침’을 마련하여 시행하였다. 본 연구에 서는 소형어선의 해양사고 감소 방안으로서 자체검사승인제도를 제시하고, 원격방식의 선박검사제도의 정형화 방안마련을 위해 모바 일 애플리케이션을 개발하여 실효성을 분석하였다. 그 결과 어선소유자의 자발적인 안전관리를 유도하기 위한 자체검사승인제도의 도 입과 함께 모바일 애플리케이션 기반 선박검사제도 도입의 필요성이 확인되었으며, 자체검사승인제도는 선박소유자의 안전의식을 고 취시켜 해양사고 감소에 대한 실효성이 있음을 확인하였다.
The purpose of this study is to analyze the adequacy of production capacity of the assembly process system of mobile bath vehicle’s top box panel and process design through a simulation analysis. Towards this end, the layout of the facility designed with pre-verification job using a simulation modeling and an experiment, and facility, logistics process, and personnel input method were made into a simulation model, and the design system’s adequacy was evaluated through an experiment. To produce 120 mobile bath vehicles annually, it was analyzed that 14 general workers and seven skilled workers were adequate through the experiment. It was also identified that three painting process lines carried out through outsourcing were adequate. Production lead time was 201.7 hours on average and it was 230 hours maximum. To meet customer delivery service level of 95% within the deadline when establishing a customer order and vehicle delivery plan, it was analyzed that more than 215 hours of lead time is needed minimum. If the process cycle time is reduced to 85% upon system stabilization and skillfulness improvement, it was analyzed that annual output of 147 vehicles can be achieved without additional production line expansion.
The object of this study is to analyse the intention to use mobile payment in transportation system through four dimensions which is cashless Characteristics, Individual Differences, Adoption Readiness and Perceived Credibility Risk. 1080 respondent data gathered by the survey method and analysed by SEM-PLS. The study shows that the main reason for the society to use mobile payment in transportation systems are the facilitating conditions and perceived usefulness. While the perceived usefulness is significantly affected by the compatibility and convenience. It brings a big impact toward the increasing use of mobile payment if the company focused on that variables for markets their products. Furthermore, the facilitating conditions can be increased by adding more infrastructure and more effective, integrated, and efficient system to also increase the convenience and compatibility of using the mobile payment. Perceived Usefulness also can be increased by adding more promotion, discount, and partnering merchants that can be used through mobile payment. This study can assist the business owner what to focus their business model to efficiently exert appropriate investment and effort in the transportation system.
Fast service access involves keeping track of the location of mobile users, while they are moving around the mobile network for a satisfactory level of QoS (Quality of Service) in a cost-effective manner. The location databases are used to keep track of Mobile Terminals (MT) so that incoming calls can be directed to requested mobile terminals at all times. MT reporting cell system used in location management is to designate each cell in the network as a reporting cell or a non-reporting cell. Determination of an optimal number of reporting cells (or reporting cell configuration) for a given network is reporting cell planning (RCP) problem. This is a difficult combinatorial optimization problem which has an exponential complexity. We can see that a cell in a network is either a reporting cell or a non-reporting cell. Hence, for a given network with N cells, the number of possible solutions is . We propose a biogeography based optimization (BBO) for design of mobile station location management system in wireless communication network. The number and locations of reporting cells should be determined to balance the registration for location update and paging operations for search the mobile stations to minimize the cost of system. Experimental results show that our proposed BBO is a fairly effective and competitive approach with respect to solution quality for optimally designing location management system because BBO is suitable for combinatorial optimization and multi-functional problems.
In this study, real-time monitoring of air quality using a real-time mobile monitoring system was conducted to identify the emission characteristics and current status of air pollutants and odorous substances that are mainly generated in domestic dyeing industrial areas and to trace the pollutant sources. The concentration of toluene in the industrial area was detected up to 926.4 ppb, which was 3 to 4 times higher than that of other industrial areas. The concentration of methylethylketone was 124.7 ppb and the concentration of dichloromethane was 129.5 ppb. Acrolein concentration was highest at E point at 521.6 ppb, methanol concentration was highest at D point at 208.8 ppb, and acetone concentration was highest at M and N points at 549.3 ppb. The most frequently detected concentration of pollutants in the air quality monitoring results in the industrial area was, in descending order, toluene > methanol > acrolein > dichloromethane > acetone, which was similar to the chemical emissions used in the industrial area by the Pollutant Release and Transfer Register data. The concentration of odorous substances measured in real time was compared with the concentration of minimum detection, and the concentration of hydrogen sulfide was about 10 times higher than the concentration of minimum detection at A point, which was judged to be the main odorous cause of A point. In the future, if the real-time mobile measurement system is constructed to automatically connect wind direction/wind speed, PRTR (Pollutant Release and Transfer Register) data and SEMS (Stack Emission Management System) data, etc., it was judged that more accurate monitoring could be performed.
Recommender systems based on Collaborative Filtering (CF) algorithms have established an extensive means for retailers to suggest personalized item lists that will maximize each consumer’s utility. Nevertheless, in the mobile game industry, which characterized by the intense competition from the avalanche of other game options and fast-changing demands of game users, there has been no marked success with recommender systems. Instead, app stores merely show summaries of general market trends without any individual-level information, fail to suggest personalized lists based on preferences of the future. For modeling dynamics of game usage, we assume that an individual’s preferences on games can be represented as the proportion of each game’s running time, which can be calculated in daily basis by the individual’s usage time for each game apps divided by the individual’s total capacity. Then, we construct a tensor filled with the induced preferences. For the next step, we apply Bayesian probabilistic tensor factorization (BPTF), an extension of Singular Value Decomposition (SVD) to consider dynamic pattern, to restore all the empty entries of the tensor. Each restored component becomes an estimate of each user’s preference on each game at certain period. For empirical analysis, we use mobile log data in app-level for total 1,000 panels over 2 years. Top 100 mobile games in cumulative usage time are treated as focal apps in this study, making the dimension of the tensor by 1000 (users) * 100 (focal games) * 730 (2 years). We compare the model performance by the root-mean-squared error (RMSE) with that of baseline model, the static counterpart in collaborative filtering algorithm (Salakhutdinov, and Mnih, 2008). The results showed that our model (BPTF) defeats the baseline throughout overall user-game pairs, especially outperforming under the conditions that there are severe fluctuations in daily usage pattern and when the life span of newly adopted apps are relatively short. Furthermore, we compose personalized suggestions, which consists of the top-10 highly likable lists according to the predicted usage patterns for each individual, and compare the performance with that of the established general recommender system in app stores. For that matter, our suggestion also outweighed the existing recommender system by the typical performance metrics that commonly used in the mobile game industry.
Using a theoretical framework of cultural capital, the present study analyzed a collecting system in AbyssRium, a mobile healing game. AbyssRium provides users with emotional satisfaction by allowing them to decorate a virtual aquarium using fishes and other sea creatures. We conducted a content analysis using contents generated in online communities and focus group interview with heavy users of AbyssRium. Results suggest that game players feel superiority by possessing rare fishes over others. These rare items were also utilized to distinguish users who collected the items from others not possessing such fishes. Also, the game operator of AbyssRium maintains the game balance by imposing greater costs for experienced users than for novice users in collecting fishes and decorate the aquarium. Such a strategy contributes to sustaining the social ecosystem of Abyssrium by encouraging new users to start to play the game. The current study suggests that a simple mobile game can afford a social interaction and a social system allowing users to constructs social meaning of artifacts presented in the virtual environments. Future research may broaden the generalizability of the cultural capital framework by replicating these findings in different video games.
It is necessary to develop a mobile water production system in order to provide stable water supply in case of disasters such as floods or earthquakes. In this study, we developed a modular mobile water production system capable of producing water for various uses such as domestic water and drinking water while improving applicability in various raw water sources. The water production system consists of three stages of filtration (sand filtration - activated carbon filtration - pressure filtration) to produce domestic water and an additional reverse osmosis process to produce drinking water. In laboratory and field experiments, the domestic water production system showed excellent treatment efficiency for particulate matter, but showed limitations in the treatment of dissolved substances such as dissolved organic matter. In addition, ultraviolet irradiation was considered as additional disinfection step, because it does not form precipitates of manganese oxides after disinfection. Reverse osmosis process was added to increase the removal efficiency of dissolved substances and the treated water satisfied drinking water quality standards. Fluorescence analysis of dissolved organic matter showed that the fulvic acid-like substances in raw water was successfully removed in the reverse osmosis process. The mobile water production system developed in this study is expected to be used not only in water supply in case of disaster, but also widely used in islands and rural area.
This paper presents how Digital Knowledge Ecosystem such as “Govi Nena” (translates as agriculture intelligence) can be used to provide a more effective and practical solution to eliminate the inefficiencies in agricultural markets and achieve higher productivity and price stability. In order to establish the framework to analyze the system, this paper uses a set of hypothetical scenarios faced by value chain actors based on a review of the literature, established knowledge and recent developing country experiences. The scenario analysis reveals that “Govi Nena” enables farmers to make effective production decisions, deepens the level of value chain integration, and enhances the level of welfare for the society as a whole.
본 연구는 한국 해군의 해난구조능력 향상을 위해 임무수행의 주요 수단이 되는 잠수체계를 개선하는 방안에 대한 연구이다. 특히 구조작전시 잠수체계별 임무 가능구역이 제한되는 문제를 해결하기 위하여 이동식 포화잠수 체계를 중심으로 연구를 진행하였다. 연구는 먼저 임무의 범위를 확인하였고, 기존 연구결과와 현용 잠수체계를 분석한 결과를 활용하여 이동식 포화잠수체계의 요구조건과 표준구성을 정리 및 제안하였으며, 이동식 포화잠수체계를 활용한 기존 잠수체계의 보완 및 개선 가능성에 대하여 군의 전략 선택 기법인적·가·용 판단에 따라 검토하였다. 또한, 도입방안에 대해서는 상용제품의 해외수입과 국내 개발로 구분하여 장·단점을 분석하고, 설치 및 운용방안에 대해서는 각 플랫폼별로 실효성을 분석하였다. 연구결과로 먼저, 200 m 이상에서 6명 이상의 잠수사가 약 17일 이상 포화잠수를 정상적으로 실시할 수 있도록 요구조건 및 표준구성안을 제안하였으며, 기존 잠수체계의 보완 및 개선 가능성에 대해서는 예비장비 공급 및 병행사용 등 다양한 보완이 기대되나 혼합기체잠수체계를 포화잠수체계로 개선하는 것은 경제성이 떨어졌다. 설치방안은 ATS-Ⅱ후속사업에서 이동식 포화잠수체계를 탑재가 가능하도록 제작하는 것을 제안하였으며 운용은 평시 교육 훈련 및 ARS 대체전력으로 사용하다 전시에 별도의 플랫폼에 탑재하여 추가적인 구조전력으로 활용해야 한다.
2013년 여름철 집중관측기간(장마기간: 2013년 6월 20일-7월 7일, 집중호우기간: 2013년 7월 8일-30일) 동안 이동식 기상관측시스템의 레윈존데 관측 자료를 전 지구 통합예측시스템 3차원 자료동화에 이용하여 그 효과를 살펴보았다. 효과 분석을 위한 2가지 모의실험 중 규준실험은 기존 기상청 관측 자료만 사용한 것이고 관측시스템실험은 기상청 관측 자료에 이동식 기상관측시스템의 레윈존데 자료를 추가한 것이다. 장마기간 동안 두 실험의 500 hPa 지위고도, 850 hPa 기온, 300 hPa 풍속의 관측 및 분석검증 비교 결과 큰 차이를 보이지 않았는데, 이는 고정관측소의 레윈존데 자료(0000 UTC 및 1200 UTC)만을 기준으로 검증이 이루어졌기 때문이다. 하지만, 종관기상관측시스템의 시간별 누적 강수량 자료를 이용한 강수검증에 있어서 관측시스템실험의 평균 공정임계지수가 규준실험에 비해 2% 수준으로 개선된 결과를 보였다. 특히 강수검증에서 긍정적인 효과가 나타난 사례만 비교한 경우, 관측시스템실험의 평균 공정임계지수가 규준실험에 비해 41%까지 개선된 결과를 보여 이동식 기상관측시스템 레윈존데 관측 자료가 수치모델의 예측정확도 향상에 유용함을 알 수 있었다.