• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 추계학술대회논문집B
• /
• pp.563-569
• /
• 2001

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and no stray currents, Hence, flow into the pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. But various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall and back-wall due to different clearances from back-wall to vertical in take pipe. Moreover, the locations and vorticities of the various types of vortices that were found in the examinations are discussed.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
• /
• pp.219-221
• /
• 1999

HVDC(High Voltage Direct Current) transmission system was constructed between Cheju island and mainland Haenam and has been operating commercially since 1998. But research activities in this area are not so much. That is caused by the facts that HVDC is large scale system and it is not so easy to implement and to test. Though such simulation tools as RTDS(Real Time Digital Simulator) and EMTDC can be useful, these have limitations for actual control and protective system design. Therefore scaled-down HVDC model was developed for the purpose of researches at operating technique, control and protection methods. The design of this model was based on real Cheju-Haenam HVDC system. And additionally faults simulator such as ground fault, short-circuit and change of impedance in transmission line is equipped for analysis of these faults. Control system of the model was implemented fully digitally. So it is very easy for the researchers to develope control and protection algorithm and to test the performance.

• 한국측량학회지
• /
• 제21권4호
• /
• pp.341-346
• /
• 2003

인터넷으로 3차원 지도 정보를 제공하기 위해서는 먼저 웹 서버가 고려되어져야 하지만, 일반적으로, 어플리케이션의 소스코드는 비공개적이며 소스 기술에 대한 접근이 어려우므로 기술개발에 많은 한계가 있었다. 본 연구에서는 이런 문제를 해결하기 위해, 공개된 소스 체제인 Linux운영체제를 도입하였고, 웹 브라우저에서 3차원 공간데이터 실행이 가능한 VRLR을 활용하여 인터넷 3차원 지도 서버를 구축였다. 그 결과, 하드웨어 구입이외의 비용은 들지 않아 경제적이었으며, 개방된 소스를 이용하므로 능동적인 유지관리가 이루어 질 수 있었다.

• 전기학회논문지
• /
• 제66권12호
• /
• pp.1792-1798
• /
• 2017

Event Data Recorder(Car Black-Box) with WiFi dongle have been released, and the platform of the majority is the Linux platform. This is because the platform development is possible in little investment cost by reducing the source licensing costs by taking advantage of the open source. But utilizing Linux platform has the limitations of boot-up time and consuming processing power due to the limitation of battery capacity, to be cost-competitive to minimize the use of memory. In this paper, the real-time operating system(RTOS) is utilized to optimize these portions. MP4 encoder and Muxer are developed to be about ten seconds boot up and minimized memory. It has the advantages of operating at lower power consumption than the Linux utilizing WiFi dongle. Utilizing a WiFi dongle is to provide a progressive download feature on smart phones to lower product prices. But RTOS has the weakness in WiFi. Porting TCP /IP, Web and DHCP server and combination with the USB OTG Host interface by implementing the protocol stack are developed for WiFi. And also SPI NOR flash memory is utilized for faster boot time and cost reductions, low processing power to be consume. As the results, the developed proved the 10 seconds booting time, 24 frame rate/sec. and 10% lower power consumption.

• 한국항공운항학회지
• /
• 제29권2호
• /
• pp.94-99
• /
• 2021

UTM is an air traffic management ecosystem under development for autonomously controlled operations of UAS by the FAA, NASA, other federal partner agencies, and industry. They are collaboratively exploring concepts of operation, data exchange requirements, and a supporting framework to enable multiple UAS operations beyond visual line-of-sight at altitudes under AGL 500ft in airspace where air traffic services are not provided. Minimum Safe Altitude is a generic expression, used in various cases to denote an altitude below which it is unsafe to fly owing to presence of terrain or obstacles. The European drone regulation mentions that the UAS is maintained within 120 metres from the closest point of the surface of the earth during flight, except when overflying an obstacle. This study attempted to develop a minimum flight altitude database system. Based on domestic and international rules and regulations on setting the minimum flight altitude it is expected that it can be applied to the operation of aircraft and unmanned aerial system in UTM environments for specific area in Korea.

• 한국물환경학회지
• /
• 제35권4호
• /
• pp.370-378
• /
• 2019

In the recent years, various studies have presented stable and economic methods for increased regulations and compliance in sewage treatment plants. In some sewage treatment plants, the effluent concentration exceeded the regulations, or the effluent concentration was manipulated. This indicates that the process is currently inefficient to operate and control sewage treatment plants. The operation and control method of sewage treatment plant is mathematically dealing with a physical and chemical mechanism for the anticipated situation during operation. In addition, there are some limitations, such as situations that are different from the actual sewage treatment plant. Therefore, it is necessary to find a more stable and economical way to enhance the operational and control method. AI (Artificial Intelligence) technology is selected among various methods. There are very few cases of applying and utilizing AI technology in domestic sewage treatment plants. In addition, it failed to define specific definitions of applying AI technologies. The purpose of this study is to present the application of AI technology to domestic sewage treatment plants by comparing and analyzing various cases. This study presented the AI technology algorithm system, verification method, data collection, energy and operating costs as methods of applying AI technology.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2022년도 추계학술대회
• /
• pp.605-607
• /
• 2022

무인이동체를 활용한 산업이 확대되면서 다수의 무인이동체를 다양한 분야에 적용하는 시나리오가 주목받고 있다. 하나의 무인이동체는 운용시간과 범위의 제약이 있어, 다수의 무인이동체를 활용함으로써 훨씬 더 넓은 범위에 서비스를 제공하고 운용시간을 단축할 수 있는 장점이 있다. 이와같은 장점을 이용해 최근에는 다수의 무인이동체를 군사용을 넘어 재난, 방송 등의 분야에 적용하려는 시도를 하고 있다. 본 논문에는 다수의 무인이동체를 이용하여 네트워크를 기반으로 원거리에서도 데이터를 주고받을 수 있는 데이터 연동 시스템에 관한 시나리오를 제시한다.

• Journal of Trauma and Injury
• /
• 제36권3호
• /
• pp.253-257
• /
• 2023

A century ago, cardiac injuries usually resulted in death. However, despite all the advances in medicine, these injuries still have high mortality and morbidity rates. In the present case, we describe a patient with a bullet injury to the right ventricle who survived at our hospital despite the limitations of our center with regard to modalities and equipment. A 30-year-old man was brought to our emergency department with a bullet wound to his left flank. He was hemodynamically unstable. After only 8 minutes in the hospital and without further investigations he was rushed to the operating room. During laparotomy, a clot was visible in the left diaphragm, which dislodged and caused extensive bleeding. The decision was made to perform a sternotomy in the absence of a sternal saw. An oblique 8-cm injury to the right ventricle was discovered following rapid exploration. It was repaired without the need for cardiopulmonary bypass surgery. After a few days in the hospital, the patient was discharged home. In the event of a penetrating cardiac injury, rapid decision-making is crucial for survival. Whenever possible, the patient should be transferred to the operating room, as emergency department thoracotomies are associated with a high mortality rate.

• 한국군사과학기술학회지
• /
• 제27권2호
• /
• pp.265-276
• /
• 2024

The future battlefield operation concept does not focus on advanced and complete weapon systems, but requires a new battlefield operation concept that can effectively demonstrate offensive power by combining a large number of low-cost, miniaturized weapons. Recently, research on the autonomous application of major technologies that make up the mission control system is actively underway. However, since the mission control system is still dependent on the operator's operating ability when operating multiple robots, there are limitations to simply applying the automation technology of the existing mission control system. Therefore, we understand how changes in operator capabilities affect multi-robot operation and propose an adaptive mission control architecture design method that supports multi-robot integrated operation by adjusting the level of autonomy of the mission control system according to changes in operator capability.

• 항공우주시스템공학회지
• /
• 제11권3호
• /
• pp.39-46
• /
• 2017

무기체계에 첨단기술이 접목되고 연구개발에 많은 비용이 듦으로써 소요군은 수명주기 전 단계에서 무기체계의 높은 신뢰도를 요구하고 있다. 하지만 국방 무기체계의 신뢰도에 대한 연구는 관심 부족 또는 자료수집의 제한으로 실증적인 연구가 제한되고 있다. 본 연구에서는 무기체계 운용자인 함정, 작전 및 정비지원 부대를 직접 방문하여 수집한 경험 및 운용자료를 바탕으로 야전운용제원 수집 프로세스를 제안하였다. 또한 해성 유도탄 발사체계의 운용 MTBF를 도출한 후 개발 시 예측값과 비교 분석하여, 예측값 대비 운용값이 저조한 부품들을 식별하였다. 연구결과를 해군 내 정비지원 부대 및 체계 개발업체에 피드백 시 해성 유도무기 발사체계의 정격 성능 유지에 기여할 수 있을 것이다.