• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집
• /
• pp.831-839
• /
• 2009

An interlocking equipment of railway signalling systems is manufactured with electrical devices and electrical interlocking equipment has been substituted for existing interlock equipment(relay sequential logic type). But interlock conditions are still generated from rail diagram and used to make Interlock Table manually. In order to make EIS(Electrical Interlock System) operate, we should write interlock data which is made from interlock table. But, as the station is larger and more complicated, handwork may becomes a very tediou work and makes more mistakes. Therefore the development of CAD system for Interlocking System is very significant, if CAD can reduce the mistakes from handwork and help the configuring the interlocking system. In this paper, we first arrange some rules which can be used to extract route information automatically from rail diagram and interlocking rules. And then we propose "Search-And-Rollback" algorithm to extract route information and individual interlocking rules. The proposed algorithm is implemented and tested through the signal design process of the Hyundai-Steel private railway to carry melted pig iron from the blast furnace to the steel-making workshop. some cases. It shows that CAD for Interlocking system is very helpful in time saving aspect and system reliability.

• 조명전기설비학회논문지
• /
• 제26권10호
• /
• pp.81-88
• /
• 2012

Surge protective devices(SPDs) are widely used as a most effective means protecting the electrical and electronic equipment against overvoltages such as lightning and switching surges. When installing SPDs, it is essential that the voltage protection level provided by SPDs should be lower than the withstand voltage of the equipment being protected. But even the proper selection of SPDs are achieved, the voltage at the equipment terminal may be higher than the residual voltage of SPD due to the reflection and oscillation phenomena. This paper was focused on the investigations of the conditions for which the equipment is protected by an SPD taking into account the influences of the protective distance and type of load. The protective effects of SPD with voltage-limiting component were analyzed as functions of types of load and protective distance between the SPD and load. As a result, in the cases of long protective distances, capacitive loads and loads with high resistance, the voltage at the load terminal was significantly higher than the residual voltage of SPD. It was found that the proper installation of SPDs should be carried out by taking into account the protective distance and type of load to achieve reliable protection of electronic equipments against surges.

• 한국BIM학회 논문집
• /
• 제11권2호
• /
• pp.24-32
• /
• 2021

Recently, starting with smart construction research, interest in technology that automates construction site management using artificial intelligence technology is increasing. In order to automate construction site management, it is necessary to recognize objects such as construction equipment or workers, and automatically analyze the relationship between them. For example, if the relationship between workers and construction equipment at a construction site can be known, various use cases of site management such as work productivity, equipment operation status monitoring, and safety management can be implemented. This study derives a real-time object detection platform architecture that is required when performing construction site management using deep learning technology, which has recently been increasingly used. To this end, deep learning models that support real-time object detection are investigated and analyzed. Based on this, a deep learning model development process required for real-time construction site object detection is defined. Based on the defined process, a prototype that learns and detects construction site objects is developed, and then platform development considerations and architecture are derived from the results.

• Structural Engineering and Mechanics
• /
• 제43권3호
• /
• pp.395-410
• /
• 2012

The visualizing energy flow and control in vibrating stiffened plates with a cutout are studied using finite element method. The vibration intensity, vibration energy and strain energy distribution of stiffened plates with cutout at different excitation frequencies are calculated respectively and visualized for the various cases. The cases of different size and boundaries conditions of cutouts are also investigated. It is found that the cutout or opening completely changes the paths and distributions of the energy flow in stiffened plate. The magnitude of energy flow is significantly larger at the edges near the cutout boundary. The position of maximum strain energy distribution is not corresponding to the position of maximum vibrational energy. Furthermore, the energy-based control using constrained damping layer (CDL) for vibration suppression is also analyzed. According to the energy distribution maps, the CDL patches are applied to the locations that have higher energy distribution at the targeted mode of vibration. The energy-based CDL treatments have produced significant attenuation of the vibration energy and strain energy. The present energy visualization technique and energy-based CDL treatments can be extended to the vibration control of vehicles structures.

• 설비공학논문집
• /
• 제25권11호
• /
• pp.578-584
• /
• 2013

Vertical open display cases are widely used in shopping malls, supermarkets, or retail stores to sell frozen and refrigerated products. Open display cases use air curtains to maintain a reasonable temperature within the storage space, prevent insects from breaking in, and reduce energy usage. In this research, computational fluid dynamics was used to find the optimal condition for reducing energy by considering various conditions such as discharge speed or temperature of air curtains. Results of the study showed that the amount of energy consumed in the display cabinet is influenced by the discharge speed and temperature of the slots installed on the upper area and the amount of air supplied to the storage area inside the shelf. This shows that the amount of discharged air supplied from the storage area influences the formation of air curtain and also the amount of energy consumption. As a result of this study, we learned that the amount of energy used can be reduced by increasing the amount of discharged air within the storage area and enhancing back pressure.

• Nuclear Engineering and Technology
• /
• 제55권2호
• /
• pp.421-431
• /
• 2023

Nuclear power plants (NPPs) have technical specifications (Tech Specs) to ensure that the equipment and key operating parameters necessary for the safe operation of the power plant are maintained within limiting conditions for operation (LCO) determined by a safety analysis. The LCO of Tech Specs that identify the lowest functional capability of equipment required for safe operation for a facility must be complied for the safe operation of NPP. There have been previous studies to aid in compliance with LCO relevant to rule-based expert systems; however, there is an obvious limit to expert systems for implementing the rules for many situations related to LCO. Therefore, in this study, we present a retrieval methodology for similar LCO cases in determining whether LCO is met or not met. To reflect the natural language processing of NPP features, a domain dictionary was built, and the optimal term frequency-inverse document frequency variant was selected. The retrieval performance was improved by adding a Boolean retrieval model based on terms related to the LCO in addition to the vector space model. The developed domain dictionary and retrieval methodology are expected to be exceedingly useful in determining whether LCO is met.

• 한국콘텐츠학회논문지
• /
• 제17권6호
• /
• pp.1-8
• /
• 2017

본 논문에서는 스마트 시대에 맞게 기존 수준측량 장비를 개선한 스마트 수준측량 장비를 개발하였다. 하드웨어부분과 소프트웨어 부분으로 나누어 개발하였으며, 다양한 수준측량 장비를 이용하여 수준점 결과 값에 대한 검측을 실시해 보았다. 수준측량의 검측방법은 국가기준점(UO992)-A, 수준점(15-00-06-24)-B, 수준점(15-00-06-23)-C로 선정하여 왕복수준측량을 실시하였다. 그 결과 오토레벨과 디지털레벨의 경우 오차범위 내의 안정된 결과 값을 얻을 수 있었고, 스마트 레벨의 경우 A-B구간에서 약 24mm, B-C구간에서 약 26mm가 발생되었다. 이는 하드웨어의 완성도가 부족한 부분이 있었고, 상대적으로 많은 설치횟수 등에 따른 오차가 발생된 것으로 판단된다. 또한 거리구간별 스마트레벨 수준측량을 실시해 본 결과 평균 RMSE가 약 46mm정도 발생되었다. 이 역시 짧은 구간에서는 적은 오차가 발생되었지만 거리가 멀어짐에 따라 오차가 누적됨을 알 수 있었다. 향후, 정밀도의 향상부분에 대하여 보다 심도 있는 연구를 추진하여 실생활에 사용가능하도록 향상할 수 있다면 다양한 산업분야에서 응용할 수 있을 것으로 판단된다.

• 한국지역사회생활과학회지
• /
• 제26권4호
• /
• pp.647-659
• /
• 2015

This study analyzes current technologies in personal protective equipment (PPE) and mechanisms that can be used in the agricultural field to provide data for research and development on PPE for farmers. There is growing awareness of the importance of PPE as part of efforts to reduce agricultural accidents, but data remain rare for developing PPE tailored to the farm work environment. In this regard, patent data on PPE can provide useful insights for facilitating relevant technologies and research. This study examines patents and utility models classified under the IPC code in Korea and other countries to analyze patented technologies and recent trends for the period from January 2003 to October 2014. Here Korea, the U.S., Japan, and Europe were considered. The results show that the number of patent applications for PPE remained steady without any sharp fluctuations. KIPO applications accounted for 43.5% of all cases, reflecting the highest proportion among the countries considered. Domestic applicants accounted for 94% of all cases. In Korea, patent applications were concentrated in safety gear for the face and eyes, indicating a high level of technology. The highest level of competition was observed for safety goggles in all countries. Some PPE technologies were dominated by a particular manufacturer. The analysis results for farming-related technologies show the current state of technologies and areas lacking technological development. This study analyzes patented technologies for PPE in Korea and other countries and recent research trends as part of the effort to develop PPE for workers in the farming and livestock industry. This study represents an early-stage effort to develop PPE for workers in the farming and livestock industry, and the results are expected to be useful for tailoring PPE to Korea's farming and livestock environment.

• 한국산학기술학회논문지
• /
• 제14권9호
• /
• pp.4447-4454
• /
• 2013

2011년 10월 국내 최초로 다목적댐 저수지에 100kW급 수상태양광발전 상용화 실증 플랜트가 합천댐에 설치되었다. 수상태양광발전 설비는 육상에 설치하는 태양광발전 설비와는 달리 수상부유체, 계류장치, 수중케이블 등 설치에 많은 어려움이 있다. 특히 수상이라는 환경적 제약으로 인해 육상 태양광 시공 방법으로 공정 관리를 할 수 없는 많은 변수가 속출한다. 수상태양광발전의 구조체는 수상태양광 모듈 및 기타 전기설비를 수상에 부상시키기 위한 설비로서 바람이나 태풍 등 기상환경에 견뎌야 하고 수질에 악영향을 미치지 말아야하며 시공성, 경제성 등 종합적인 고려가 필요하다. 본 논문에서는 100kW 수상태양광 시공사례를 바탕으로 수상태양광의 구조체, 계류장치, 수중케이블, 전력설비 및 원격감시제어시스템의 시공기술에 대한 기초자료를 제공하였다. 본 연구에서 시공된 100kW 수상태양광은 현재 평균 설비이용률 15%로 운영중에 있다.

• Journal of Preventive Medicine and Public Health
• /
• 제21권1호
• /
• pp.113-120
• /
• 1988

A total of 181 cases of industrial ocular injuries hospitalized and treated at the St. Mary's Hospital, Seoul during the 5-year period was studied on their epidemiological characteristics. Of these patients 96.7% were males, and 43.6% were in twenties, 49.7% of the cases were injured on left eyes. There were no statistically significant differences in frequencies of study subjects by day of the week and month of the year. Most common injury hour were between 10- <12 AM(13.6%) and between 2- <4 PM(20%). Of the total 101 cases, 37.6% were working less than 6 months, and 73.7%, less than 2 years. Of the total, 42.3% were involved in machinary work and 13.9%, in construction work. According to the American National Standard Method of recording basic facts relating to the nature and occurrence of work injuries, 62%, among all source of injuries was metal item and the most common accident type was struck by flying objects(76.2%). Among 181 cases, only 2 cases were wearing protective equipment when the accidents occurred.