• 한국항해항만학회지
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• 제33권1호
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• pp.35-41
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• 2009

워터젯이 탑재된 RIB(Rigid Inflatable Boat)형태의 무인수상선을 인한 경유점 추적 제어 알고리즘을 설계하였고, 성능 검증을 위해 실해역 시험을 수행하였다. 본 연구에서 사용된 RIB형 무인수상선의 경유점 추적제어를 위해서는 방향제어를 위해 버킷각을 제어하여야 한다. 우선, 육상 관제소에 미리 입력된 경유점들의 위경도 등의 위치정보들을 바탕으로, 목표 방향각을 실시간 계산한다. 그리고, 무인수상선에 탑재된 마그네틱 콤파스 등의 센서로부터 받은 선수각 및 선수각속도의 값과 PD 제어기법을 이용하여, 버킷각 명령을 실시간 계산한다. 본 연구에서는, 바람 등의 외력으로 인한 표류각을 보정하기 위해 일정속도 이상에서는 실침로(Course Of Ground, COG)를 사용하였다. 또한, 설계된 경유점 추적 제어 알고리즘을 검증하기 위해 부산 광안대교 근처 해역에서 육상관제소를 설치하고, 실선 시험을 수행하였다. 본 논문에서는, 설계된 무인 경유점 추적 제어 알고리즘의 시험결과를, 유인으로 제어한 결과 및 상용추적제어기로 제어한 결과들과 비교 분석하였다.

• 한국산학기술학회논문지
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• 제14권3호
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• pp.1402-1408
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• 2013

문서관리는 기업 내의 프로젝트의 업무수행을 원활히 하기 위해 특히 중요하다. 소규모 프로젝트의 경우에, 문서관리 기준이 협업부서 사이에 다른 경우가 많으며, 업무 프로세스에 대한 문서구조 변경이 프로젝트 기간 동안 빈번히 일어난다. 본 논문은 P2P 기반의 문서 모니터링 시스템을 설계 및 구축을 제안한다. 제안된 문서관리 모니터링 시스템은 소규모 프로젝트의 특정 작업 프로세스 및 시간제약을 보완하며, 작업 프로세스를 중심으로 문서의 생성, 공유 및 배포의 상태를 효율적으로 모니터링 할 수 있다. P2P를 사용함으로써 소규모 프로젝트에서 저비용으로 구축하여 사용할 수 있는 장점이 있다.

• 한국운동역학회지
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• 제24권4호
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• pp.349-357
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• 2014

The purpose of this study was to examine the differences in the performance of dancing motions depending on the level of skill by investigating pulmonary functions, ground reaction force, and jerk cost. The subjects of this study were 12 professional dancers (career: 16 yrs) and 12 amateur dancers (career: 9 yrs) who had similar physical conditions. We selected four motion phases which included the diagonal line motion, the deep flexion motion, the breath motion, and the turn motion with one leg after a small step walking motion, with Goodguri Jangdan. In the experiment, 6 infrared cameras were installed in order to analyze the value of the jerk costs and the force plate form. Finally, we measured the pulmonary functions of the subjects. For data analysis, independent t-tests according to each event, were carried out in the data processing. According to the results of FVC % Predicted, the professional dancers showed greater lung capacities than the amateur dancers, indicating that the level of dancing skill influences lung capacity. Based on the result of the balance test, the professional dancers used more vertical power than did the amateur dancers when performing maximal flexion motion. The professional dancers used a propulsive force of pushing their body forward by keeping the center of body higher while the amateur dancers used a braking power by keeping their bodies backward. When performing medial-lateral movements, the amateur dancers were less stable than the professional dancers. There were no differences in values of jerk costs between the amateur dancers and the professional dancers.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.989-995
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• 2018

Argonne National Laboratory of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have cooperated on the development, design, and construction of a neutron source facility. The facility was constructed at Kharkov, Ukraine, and its commissioning process is underway. The facility will be used for researches, producing medical isotopes, and training young nuclear specialists. The neutron source facility is designed with a provision to include a cryogenically cooled moderator system-a cold neutron source (CNS). This CNS provides low-energy neutrons, which will be used in the scattering experiment and material structures analysis. Cold neutron guides, coated with reflective material for the low-energy neutrons, will be used to transport the cold neutrons to the experimental site. The cold neutron guides would keep the cold neutrons within certain energy and angular space concentrated inside, while most of the gamma rays and high-energy neutrons are not affected by the cold neutron guides. For the KIPT design, the cold neutron guides need to extend several meters outside the main shield of the facility, and curved guides will also be used to remove the gamma and high-energy neutron. The neutron guides should be installed inside a shield structure to ensure an acceptable biological dose in the facility hall. Heavy concrete is the selected shielding material because of its acceptable performance and cost. Shield design analysis was carried out for the CNS guide hall. MCNPX was used as the major computation tool for the design analysis, with neutron and gamma dose calculated separately. Weight windows variance reduction technique was also used in the shield design. The goal of the shield design is to keep the total radiation dose below the $5.0{\mu}Sv/hr$ guideline outside the shield boundary. After a series of iterative MCNPX calculations, the shield configuration and parameters of CNS guide hall were determined and presented in this article.

• 동력기계공학회지
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• 제6권1호
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• pp.20-26
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• 2002

The purpose of this study is preventing the stick, scuffing, scratch between piston and cylinder in advance, and obtaining data for duration test in actual engine operation. The temperature gradient in cylinder bore according to coolant temperature were measured using $1.5{\ell}$ class diesel engine. 20 thermocouples were installed 2mm deep inside from cylinder wall near top ring of piston in cylinder block, at which points major thermal loads exist. It is suggested as proper measurement points for engine design by industrial engineers. Under full load and $70^{\circ}$, $80^{\circ}C$ and $90^{\circ}C$ coolant temperature conditions, the temperature in cylinder block and engine oil increased gradually according to the increase of coolant temperature, the siamese side temperature of top dead center is $142^{\circ}C$ in peripheral distribution, that is about $20^{\circ}C$ higher than that at thrust, anti-thrust, and rear side temperature, respectively. The maximum pressure of combustion gas in $70^{\circ}C$ coolant temperature is about 2 bar lower than those of $80^{\circ}C$ and $90^{\circ}C$ coolant temperature. The engine torque in $80^{\circ}C$, $90^{\circ}C$ coolant temperature condition is about 4.9Nm higher than that of $70^{\circ}C$ coolant temperature.

• 토지주택연구
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• 제8권3호
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• pp.161-169
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• 2017

In this study, sediment transfer and precipitation analysis of the test bed watershed was conducted through the model for the application and practical use of the urban sediment disaster prevention technology, and used this as an aid to design to secure reliability. In addition, conducted the test bed monitoring with the defense technology, analyzed the effect, and established the maintenance plan. Analyzed the change of soil deposition volume through arbitrary slope adjustment for the currently installed stormwater conduit of the test bed watershed. As a result, it is important to reduce the total sedimentation amount in the adjustment of the slope of the entire pipeline, but it is important that the sedimentation depth of each sediment does not rise to such a degree as to threaten the performance of the pipeline. Considering these matters, it is necessary to design the pipeline to prevent the clogging of the soil from the viewpoint of the reliability of the entire pipeline. The sediment disaster defense technology test bed is divided into a new city and an old city, and old city test bed is under construction. The result obtained through the monitoring of the test bed in the new city, sediment disasters such as debris can delay the time to reach the downtown area, and it is possible to secure the golden time, such as evacuation and rescue through the warning system. Also, the maintenance of the test bed application was suggested. Continuous and systematic monitoring is required for securing the reliability of element technology and successful commercialization.

• 대한기계학회논문집A
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• 제35권2호
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• pp.207-212
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• 2011

유압 브레이커는 굴착기의 암 끝에 장착되어 파쇄작업을 하는 부착작업기이다. 그러나 굴착기의 성능에 치명적인 영향을 미치는 유압 브레이커의 중량에 대한 연구는 아직 없었다. 따라서 본 연구에서는 유압 브레이커에서 대부분의 중량을 차지하고 있는 하우징에 대한 최적설계를 수행하였다. 유압 브레이커 하우징의 설계 요구사항은 정상 운전상태에서 파손없이 중량을 최소화하는 것이다. 직교배열표를 이용하여 실험점을 선정하였고, 실험점에서의 결과를 바탕으로 근사모델을 생성하여 최적 설계안을 도출하였다. 그 결과, 모든 구속조건을 만족하면서 유압 브레이커 하우징의 중량을 4.8% 감소시켰다.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2006년도 추계학술대회 논문집
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• pp.17-20
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• 2006

Passenger safety is fundamental factor in automobile. Among much equipment for passenger safety, the air bag system is the most fundamental and effective device. Beside of the front air bag system which installed on most of all automobiles, a curtain-type air bag is increasingly adapted in deluxe cars fur protecting passengers from the danger of side clash. Curtain type airbag system consists of inflator housing, fill hose, curtain airbag. Inflator housing is a main part of the curtain-type air bag system for supplying high-pressure gases to deploy the air bag-curtain. Fill hose is a passageway to carry the gases from inflator housing to each part of curtain airbag. Therefore, it is very important to design the vent holes of fill hose for good performance of airbag deployment. But, the flow information from vent holes of fill hose is very limited. In this study, we measured instantaneous velocity fields of a high-speed flow ejecting from the vent holes of fill hose using a dynamic PIV system. From the velocity Held data measured at a high frame-rate, we evaluated the variation of the mass flow rate with time. From the instantaneous velocity fields of flow ejecting from the vent holes in the initial stage, we can see a flow pattern of wavy motion and fluctuation. The flow ejecting from the vent holes was found to have very high velocity fluctuations and the maximum velocity was about 480m/s at 4-vent hole region. From the mass flow rate with time, the accumulated flow of 4-vent hole has occupied about 70% of total flow rate.

• 한국산업융합학회 논문집
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• 제20권2호
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• pp.105-113
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• 2017

Recently the direct injection diesel engine is the most efficient one available for road vehicles, so this fundamental advantage suggests the compression injection diesel engine are a wise choice for future development efforts. The compression ignition diesel engine, with its bigger compression ratios if compared to the SI engine, offers a higher thermodynamic efficiency, also additionally the diesel engine with its less pumping losses due to the throttled intake charge as in a SI engine has higher fuel economy. But the largest obstacle to the success of this engine is meeting emission standards for Nitric oxides and particulate matter while maintain fuel consumption advantage over currently available engines. Thus its use should be largely promoted, however, diesel engine emits more Nitric oxides and particulate matter than other competing one. There has been a trade-off between PM and NOx, so efforts to reduce NOx have increased PM and vice versa, but trap change this situation and better possibility emerge for treating NOx emission with engine related means, such as injection timing, equivalence ratio, charge composition, and engine speed. The common rail direct injection system is able to adjust the fuel injection timing in a compression ignition engine, so this electronically controlled injection system can reduce the formation of NOx gas without increase in soot. In this study it is designed and used the engine test bed which is installed with turbocharge and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and exhaust emission as operating parameters.

• 수산해양기술연구
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• 제50권3호
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• pp.326-333
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• 2014

This study was conducted to investigate the fishing efficiency of an improved LED fishing lamp for squids. A total of 31 fishing operations were carried out with six-crew commercial fishing vessel Haengbok-Ho (24 tons) on which 43.2kW LED was installed, along with 14 automatic jigging machines, from October 6 to November 16, 2012. The 19 fishing vessels with Haengbok-Ho were compared with a control subject was 24 tons or 29 tons. A total illuminating power of metal halide (MH) fishing lamps in the control fishing vessel was either 84kW or 120kW. The number of automatic jigging machines in the control vessels was 8-18 and the number of crews engaged for fishing operation was 3-13. Average fuel consumption of LED fishing vessels during fishing operation was 505.1l which led to an average fuel consumption of 42.7l per hour. LED fishing vessel and MH fishing vessel caught on an average 1,946 squids and 2,439 squids, respectively, during the study period. Crews (hand line and hand reel) caught about 2.2 times the automatic jigging machines for LED fishing vessel and about 2.1 times for MH fishing vessel. Meanwhile, catches by the fishing vessels with LED in the combined total number per one line of automatic jigging machine and per crew were 86.6% of that of the control fishing vessel with MH. Also, fishing vessels with LED per automatic jigging machine achieved 71.8% of catches of that with MH fishing lamp. The catches of squids per the fishing vessel with 1W LED fishing lamp were higher by more than 135.5% of that in the fishing vessel with MH, which showed a good fishing performance even with only the use of a LED fishing lamp.