본 연구는 다시마 양식을 위한 통합 자동화 시스템을 개발하고, 이를 통해 생산성, 비용 효율성, 환경적 지속 가능성을 모두 개선하는 데 중점을 두고 있다. 기존의 노동 집약적 수확 방식과 넓은 공간을 필요로 하는 수평 건조 방식은 비효율적이며, 환경적 부작 용을 초래했다. 이에 본 연구는 자동화된 수확 시스템, 해상-육상 연계 운송 시스템, 그리고 수직 건조 시스템을 통합적으로 개발하여 양 식업의 생산성을 극대화하고 자원 사용을 최적화하였다. 자동화된 수확 시스템은 작업 속도를 약 35% 향상시켰으며, 작업의 일관성을 유지하여 품질 오차율을 2% 이하로 줄이는 성과를 보였다. 해상-육상 연계 운송 시스템은 모듈형 컨테이너를 활용하여 운송 중 손상률 을 기존 15%에서 5%로 감소시켰고, 운송 시간을 평균 6시간에서 4시간으로 단축하였다. 또한, 수직 건조시스템은 고밀도 적재와 자연 대류 방식을 도입하여 건조 시간을 기존 48시간에서 28시간으로 40% 단축하였으며, 에너지 소비를 25% 감소시켰다. 이러한 시스템은 데이터 기반으로 설계 및 검증되었으며, 통합적으로 양식업의 경제성 향상과 환경적 부담 감소를 동시에 실현하였다. 본 연구의 결과는 다른 해조류 양식에도 적용 가능하며 지속 가능한 해양 자원 관리에 기여할 것으로 기대된다.
본 연구는 구조주의 비평을 활용하여 구약성서의 ‘소돔과 고모라’ 이야기( 창 세기 19:1-38)를 한국 전통 설화인 <장자못> 설화와 비교함으로써, 고대 이스 라엘과 한국 전통 설화에 내재한 ‘금기’와 ‘위반’이라는 원형적 상상력과 사유 체계를 지배하는 심층구조를 고찰한다. 두 이야기는 서로 다른 문화적 배경에도 불구하고, 금기와 위반이라는 주제를 중심으로 여성의 석화(石化)라는 공통된 구조적 모티프를 공유한다. <장자못> 설화에서는 하나님의 천사 대신 스님이 등 장하고, 롯의 아내 대신 착한 며느리가 등장하는 등 문화적 요소의 차이가 존재 하지만, ‘뒤돌아보지 말라’는 금기 위반으로 인한 변신이라는 서사 구조는 유사 하다. 롯의 아내가 정화, 보전, 불멸, 계약을 상징하는 ‘소금’ 기둥으로 변하고, <장자못> 설화의 며느리 역시 금기 위반으로 ‘돌’이 되는 변신은 성스러움과 속 됨의 경계에 위치한 인간의 존재와 통과 의례의 어려움을 상징하며, 인간의 연 약함과 경계 넘기의 한계를 드러낸다.
Various road traffic signs are placed on the shoulder to inform drivers of the work situation ahead, speed limits, and lane changes in highway work zones. In this study, we analyze the effectiveness of a portable lane-change assistance system (PLCS) that can replace existing traffic signs from the perspectives of driver visibility and lane-change behavior. The existing highway work zone traffic management guidelines were regarded as a scenario without PLCS, and the case of replacing the existing traffic signs proposed by the manual with PLCS was set as a scenario with PLCS. For each analysis scenario, we analyzed the change in subjective awareness of traffic signs, perception accuracy of PLCS, advance lane-change rate, and lane-change location. The subjective perception analysis showed that the subjective perception change rate increased by 13.85% for two-lane highways and 5.29% for three-lane highways when PLCS was applied compared to that without PLCS. Regarding PLCS perception accuracy, all drivers correctly recognized the lane closure information for the two-lane case. Two PLCS are used in the three-lane case to provide lane-closure information. Regarding the first PLCS, all drivers correctly recognized lane closure information for the first lane sign, and 31 drivers correctly recognized lane closure information for the second and third lane signs. Regarding the second PLCS, all drivers correctly recognized lane closure information for the first and third lane signs, and 30 drivers correctly recognized lane closure information for the second lane sign in the second PLCS. Analysis of lane-change behavior showed that the proportion of advance lane changes increased by 31.25% in the two-lane case and 59.38% in the three-lane case with PLCS compared to that without PLCS. Additionally, lane-change locations where drivers performed lane changes from the starting point of the work zone area were analyzed. Drivers changed lanes at 653.68 m without PLCS and at 919.66 m with PLCS resulting in a 265.98 m increase in lane change location for the two-lane case. The drivers changed lanes twice in the three-lane scenario. Drivers changed lanes at 1014.41 m and 743.64 m without PLCS and at 1137.05 m and 868.24 m with PLCS, resulting in a 122.64 m and 124.60 m increase in the lane change location for the three-lane case. The proposed PLCS demonstrated a greater recognition capability than existing traffic signs and was effectively encouraged. This can be useful for replacing existing traffic signs in highway work zones.
This study evaluates the long-term performance of a multi-layer cover system (MLCS) for near-surface disposal facilities using numerical modeling to estimate infiltration rates under various rainfall scenarios. An effective cover system is essential to prevent radionuclide migration and protect groundwater inflow within disposal facility. The analysis incorporated different bedrock characteristics (homogeneous and discrete fracture networks) and rainfall patterns throughout a 300-year post-closure period, assuming constant initial hydraulic properties. A comprehensive modeling approach incorporating both saturated and unsaturated flow dynamics was employed to assess system performance. Results showed that the cover system effectively limited infiltration rates to 15.94%−21.25% of the design criterion (32 mm∙year−1) across all scenarios. Although infiltration patterns showed minimal sensitivity to bedrock heterogeneity, preferential flow along fractures was observed in the unsaturated zone, necessitating further investigation. These findings emphasize the importance of considering fracture-dominated flow in cover system design and highlight the need for detailed analysis of chemical degradation effects, experimental validation, and uncertainty quantification. The study provides valuable insights for optimizing disposal facility designs and improving long-term performance assessment methodologies.
This study aims to identify crisis signs in small and medium enterprise (SME)-concentrated regions and establish measures to prevent economic recession and normalize regional economies through proactive responses. To achieve this, we investigated and analyzed the crisis status and outlook of companies located in Jeonbuk, their detailed management conditions, management issues by industry, difficulties in business operations, and policy demands. Out of 4,144 SMEs in Jeonbuk's concentrated areas, 270 companies responded to the survey. The results showed that 60% of the responding companies perceived their current management situation as being in a state of crisis. However, the outlook for the next quarter and the following year is expected to improve. Notably, compared to manufacturing companies, non-manufacturing firms responded that their crisis situation in the next quarter would not improve and expected the crisis to persist. In terms of detailed business conditions, regardless of the distinction between manufacturing and non-manufacturing sectors, all aspects of the survey, including domestic sales, export sales, operating profit, financial status, and the number of employees, indicated better prospects for the next quarter and the following year compared to the current quarter. The study's findings suggest that companies in SME-concentrated areas of Jeonbuk are relatively accurate in recognizing the crisis situation of their own businesses and operating markets. Additionally, the companies responded that crisis monitoring is necessary. Differences in difficulties faced by the manufacturing and non-manufacturing sectors imply the need for industry-specific financial support programs. Based on the survey results, we propose financial support projects tailored to the manufacturing and non-manufacturing sectors, considering the degree of market competition. For more precise research, future studies will involve extracting larger samples and conducting a detailed analysis by subdividing manufacturing sectors (e.g., food, metal) and non-manufacturing sectors (e.g., agriculture, design).
Background: Interest in cardiac rehabilitation therapy has been increasing in Korea after the addition of cardiac rehabilitation as a benefit item in the National Health Insurance Service in 2017. However, few epidemiological studies have characterized cardiac rehabilitation in Korea. Objects: To assess the national epidemiological data on cardiac rehabilitation therapy in Korea from 2017 to 2023. Methods: This study analyzed MM453, a prescription code for cardiac rehabilitation therapy in the Health Insurance Review and Assessment database. The data reviewed included the total number of cases per year and the number of cardiac rehabilitation therapy prescriptions per 100,000 people, along with sex and age distribution of patients undergoing cardiac rehabilitation therapy. Results: The number of cardiac rehabilitation therapy prescriptions in Korea increased from 4,443 in 2017 to 15,646 in 2023 (252.1% increase in 7 years). The incidence per 100,000 person-years rose from 8.64 in 2017 to 30.22 in 2023. The number of males undergoing therapy increased from 3,183 (incidence: 12.35) in 2017 to 11,276 (incidence: 43.53) in 2023. The number of females undergoing therapy increased from 1,260 (incidence: 4.91) in 2017 to 4,370 (incidence: 16.89) in 2023. The highest number of patients undergoing therapy from 2017 to 2023 was observed in the 60s age group (patients: 4,747, incidence: 9.17), followed by the 70s, 50s, and > 80s age groups. Conclusion: From 2017 to 2023, the number of patients undergoing cardiac rehabilitation therapy in Korea increased consistently. The therapy is approximately 2.6 times more common in males than that in females and is predominantly administered to individuals in their 60s, followed by those in their 70s, 50s, and 80s and above.
Sequential zone picking is an order picking method designed to enhance warehouse efficiency by dividing the storage area into multiple zones and picking items in a sequential order across these zones. Picked items are often placed in dedicated totes and transported between zones using a conveyor system, which manages the picking flow but can occasionally result in inefficiencies during the process. This study presents a variant of the sequential zone picking system, called a dual-lane zone picking system (DZP), which consists of two parallel conveyor lanes without buffers between consecutive zones. This conveyor configuration allows the picker in each zone to alternate processing between the two lanes, thereby lessening the constraints of tote transitions between zones and improving both system throughput and picker utilization. We design and conduct a series of experiments using a discrete-event simulation model to evaluate the performance of DZPs. The experiment results indicate that DZP surpasses the original single-lane zone picking system by shortening the system’s mean flow time in low flow intensity scenarios and achieving a higher maximum throughput and worker utilization in high flow intensity scenarios. Additionally, we investigate the effects of the number of zones and order batching size on the performance of DZP to gain further insights into the system’s operational control.
Bearing-shaft systems are essential components in various automated manufacturing processes, primarily designed for the efficient rotation of a main shaft by a motor. Accurate fault detection is critical for operating manufacturing processes, yet challenges remain in sensor selection and optimization regarding types, locations, and positioning. Sound signals present a viable solution for fault detection, as microphones can capture mechanical sounds from remote locations and have been traditionally employed for monitoring machine health. However, recordings in real industrial environments always contain non-negligible ambient noise, which hampers effective fault detection. Utilizing a high-performance microphone for noise cancellation can be cost-prohibitive and impractical in actual manufacturing sites, therefore to address these challenges, we proposed a convolution neural network-based methodology for fault detection that analyzes the mechanical sounds generated from the bearing-shaft system in the form of Log-mel spectrograms. To mitigate the impact of environmental noise in recordings made with commercial microphones, we also developed a denoising autoencoder that operates without requiring any expert knowledge of the system. The proposed DAE-CNN model demonstrates high performance in fault detection regardless of whether environmental noise is included(98.1%) or not(100%). It indicates that the proposed methodology effectively preserves significant signal features while overcoming the negative influence of ambient noise present in the collected datasets in both fault detection and fault type classification.
본 연구는 금속성 물질로 인해 발생하는 자화율 인공물(susceptibility artifact)의 정확한 길이 측정을 위해 자체 제작한 팬텀을 이용하여 분석하였다. 치과용 임플란트 고정체를 자체 제작한 아크릴 팬텀에 위치시키고, T2 강조 영상을 통해 자화율 인공물을 검사하였다. 자화율 인공물의 길이를 팬텀 기반 측정법과 선 프로파일 기반 측정법을 사용하여 분석하였고 팬텀 기반 측정법을 기준값으로 선 프로파일 기반 측정법으로 도출된 결과와 비교하였다. 결과 적으로 선 프로파일 기반 측정법에서 배경 신호 기준 25% 허용 범위를 설정했을 때 팬텀 기반 측정법과 가장 유사한 데이터를 얻을 수 있었다. 이를 통해 선 프로파일 기반 측정법이 자화율 인공물 길이의 정량적 측정에 적합할 수 있는 가능성을 확인하였다. 추후 미흡한 부분을 보완한 추가 연구를 통해 자화율 인공물 연구에서 객관적인 데이터 제공이 가능할 수 있게 되기를 기대한다.
In this study, fire extinguisher system to which form fire extinguisher agents were adopted was applied to the combat vehicle crew room to apply fire extinguishing performance and acid gas safety that meet the national defense standards. As a result of evaluation and verification, the following conclusions were drawn. For standard fire sizes in the combat vehicle crew's standard model, we ignited using a mixture of Novec 1230 and Halon 1301 form extinguisher agent and released form extinguisher agent after 30 seconds to determine the fire extinguishing time. The amount of acid gas generated met the criteria in all cases. When the fire size was increased to 0.12m2 and a 2.0mm nozzle was used, all of the extinguishing time, the amount of acid gas generated, and the concentration of Novec 1230 met the criteria. Despite the more difficult conditions to extinguish the fire by making the fire larger, it was possible to confirm the extinguishing performance of the Novec 1230 form extinguisher agent and its safety against acid gas.
현재 기후변화 문제 해결을 위한 국제적 목표 및 국내 에너지 정책에 부합하는 LNG 발전의 효율성을 극대화하는 방안이 요구 되고 있다. 2050년 탄소중립 목표 달성을 위해 각국은 2030년까지 온실가스 감축 목표를 설정하였고, 국내에서도 석탄 발전 시설을 단계 적으로 폐쇄하고 LNG 발전 시설을 확대하려는 노력이 진행되고 있다. 이 연구에서는 LNG의 재기화 과정에서 발생하는 냉열을 회수하여 Carbon Capture and Storage, Ammonia-water Rankine Cycle / Kalina Cycle, Data Center Cooling, Direct Expansion 공정에 활용할 수 있는 시스템을 제안하였다. 연구 결과 제안된 시스템의 3E 분석 결과 Energy 효율 51.52%, Exergy 효율 42.74%, 환경적 측면에서 2,145.8 gCO2 / kgLNG의 탄 소 배출량을 보여 가장 우수한 성능을 확인하였다. 이를통해 본 연구에서 새롭게 제시한 시스템은 Energy, Exergy, 환경성 측면에서 강점을 가지며, 향후 기후변화 대응에 크게 기여할 것으로 판단된다.
With technological and social development, high-rise atypical buildings have emerged. In order to take into account the structural vulnerability due to their high-rise atypical shape, systems such as vibration control system and seismic isolation can be applied. In this study, dynamic behavior characteristics analysis was conducted based on the location of the seismic isolation system installation of the atypical facade shape Tapered and reverse shell structure models. With the installation of Lead Rubber Bearing(LRB), the maximum story drift ratio showed a decrease, but the maximum absolute acceleration showed a phenomenon in which the response was amplified in the middle and low story. LRB1(base isolation system) is the most effective for simultaneous control of the two dynamic responses, but the 46th floor of ‘Nor’ and’ RS’ and the 41st floor of ‘TA’ are considered the most effective installation location of the seismic isolation system in consideration of the burden of the seismic isolation system and the structure stability.
The dome structure is suitable as a roof for large spatial structures because it can maintain the shape without installing columns in the internal space. However, the structure characteristics of the lower and upper structures of the dome structure are different, and damage may occur when an earthquake occurs. Therefore, in this study, mid-story isolation system was applied to the ribbed dome and geodesic dome structures to analyze the seismic response of the lower and upper structures according to the dome shape. As a result of the analysis, the displacement of the ribbed dome increased, but the deformation of the ribbed dome and the response of the lower structure decreased, and the seismic response of the geodesic dome decreased overall. From this result, the effect of the isolator according to the shape of the dome structure was confirmed, and the mid-story isolation is considered effective in reducing the seismic response of the upper and lower structures.
우리나라 헌법 제107조 제3항은 재판의 전심절차로서 행정심판을 할 수 있 으며 절차는 법률로 정하되, 사법절차가 준용되어야 한다고 규정한다. 그리고 행정심판법 제4조 제1항에서는 사안의 전문성과 특수성이 인정되면 필요에 따 라 개별법이 정한 특례절차에 따라 심판을 할 수 있도록 규정하고 있다. 이러 한 특례절차에 따른 행정심판을 특별행정심판이라 하는데, 해양안전심판, 특허 심판 및 조세심판 등이 있다. 특별행정심판 중에서도 해양안전심판은 해양사고의 원인규명재결뿐만 아니 라 해기사 등에 대한 징계재결까지도 심판의 결과로 도출하는 특별한 형태의 행정심판으로서 구술변론주의, 대심주의 및 조사관의 청구독점주의 등을 채택 하고 있다. 그러나 조사관은 해양사고관련자를 조사하는 권한을 가지고 있어 해양사고관련자와 대등한 입장이라 보기 어렵다. 그러므로 상대적 약자인 해양 사고관련자의 정당한 권리구제와 방어권을 보장하기 위해서는 심판변론인 제 도의 적극적 활용이 무엇보다 중요하다. 이 연구에서는 해양사고심판의 심판변론인제도를 다양한 측면에서 살펴보 고, 다른 특별행정심판인 특허심판과 조세심판 제도와 비교·분석하여 해양안전 심판의 심판변론인제도에 대한 문제점을 도출하고 개선방안을 제안하고자 한다.
This study is about the evaluation for shock-proof performance of the system, elastically support the low accumulator of the naval artillery against underwater explosion, using DDAM. For the evaluation, the shock analysis procedure using DDAM, supported by MSC/NASTRAN, was briefly described. In addition, in order to perform the shock analysis, the elastic support system was modeled as a finite element. The shock analysis of the elastic support system was performed by selecting the analysis frequency range so that reliable results can be obtained. Finally, the shock-proof performance of the system was evaluated by comparing the shock analysis results with the properties of the elastic support system.