• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.2
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• pp.90-101
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• 2009

Analysis of multi-channel seismic reflection data from the Southern Ulleung Basin reveals that Plio-Quaternary section in the area consists of nine stacked sedimentary units separated by erosional unconformities. On the southern slope, these sedimentary units are acoustically characterized by chaotic seismic facies without distinct internal reflections, interpreted as debris-flow bodies. Toward the basin floor, the sedimentary units are defined by well-stratified facies with good continuity and strong amplitude, interpreted as turbidite/hemipelagic sediments. The seismic facies distribution suggests that deposition of Plio-Quaternary section in the area was controlled mainly by tectonic movement and sea-level fluctuations. During the Pliocene, sedimentation was mainly controlled by tectonic movements related to the back-arc closure of the East Sea. The back-arc closure that began in the Miocene caused compressional deformation along the southern margin of the Ulleung Basin, resulting in regional uplift which continued until the Pliocene. Large amounts of sediments, eroded from the uplifted crustal blocks, were supplied to the basin, depositing Unit 1 which consists of debris-flow deposits. During the Quaternary, sea-level fluctuations resulted in stacked sedimentary units (2-9) consisting of debris-flow deposits, formed during sea-level fall and lowstands, and thin hemipelagic/turbidite sediments, deposited during sea-level rise and highstands.

• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.49-58
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• 2011

It is required that a developed control system should be verified using simulator in terms of functionality and reliability prior to application to a power plant that is a very critical facility in the industry. In this paper, the control model for turbine bypass system was developed for power plant simulator. In order to develop the control model for turbine bypass system, the tool that can be used to implement turbine bypass control logic was developed based on the turbine bypass control system manual. The developed tool was merged into the simulator development environment. The functionality of the developed tool was verified via the simulation based on the each function block specification. The HP turbine bypass pressure control logic was implemented using the developed tool and was integrated with process models and other control models such as boiler control model, turbine control model and boiler feed water pump turbine control model for 500 MW korean standard type fossil power plant. Finally, the validity of the developed control model was shown via simulation result under the integrated simulation environment.

• Journal of the Korean Institute of Gas
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• v.17 no.3
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• pp.8-13
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• 2013

The purpose of this paper is to study for fire example by fuel leakage in LPG Vehicle. At first example, the car was repaired the fuel line that was connected with pressure hose between fuel regulator and injector in engine. But the service man was not very tighten with regular torque. At a result, the gas leaked on hot parts of engine. It verified the production of fire by engine heat. At second example, when the repair man, after replacement the injector, inserted the injector in a assembling part of it, he didn't the transform condition of fixing part. Therefore, the tearing phenomenon of O ring producted the controlled leakage of fuel by the injector deflection. It found the fact that the fuel leaked with gap of O ring. At third example. the fuel-cut solenoid valve was lined with pressure regulator unit. But the service man didn't throughly certify the leaked work of connected parts after repaired it. As a result, it certified the fire by engine heating leaked liquefied petroleum gas. Therefore it have to minimize the fire production that the driver should do no problem to throughly manage the fuel system.

• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.573-579
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• 1996

Effects of operating variables on the conversion of the formation reaction of meta boric acid from ortho boric acid in a laboratory-scale bubble column reactor were investigated to obtain the basic data which are indispensable for the design, scale-up, control, development and operation of industrial bubble column reactors. Reaction time and pressure, particle size of reactant and gas flow rate were chosen as experimental variables. Effects of the experimental variables on the gas holdup in the bubble column reactor were also discussed in relation to the conversion of reaction. From the results of this study, the optimum conditions were drawn as follows : Reaction time ; 35~40(min), reaction pressure ; 92~95(kPa), particle size ; under $0.6{\times}10^{-3}(m)$, gas flow rate ; 0.07~0.08(m/s).

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.403-404
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• 2008

자원의 고갈과 각종 환경규제 및 정부의 전력거래 방침 등으로 인해 점점 발전소에서는 전력 계통에 대한 신뢰도 및 전기품질을 유지하기가 어려워지고있다. 발전소의 부하대별 주요 운전 설계값은 효율과 바로 직결되는 사항으로 각 부하별로 온도와 압력 등 운전설계값을 최적의 상태로 유지하는 것은 발전소 수명과 발전효율, 전력거래 등에 있어 중요한 요소들이다. 전력시장에 진입하는 발전소는 전력계통의 갑작스런 불안성 상황이나 전력거래소 요청시 경사변동폭, 출력변통율, 무효전력 출력, 자동발전제어, 주파수조절량 확보 등을 수행할 수 있어야 한다. 본 논문에서는 고급공정제어기를 이용하여 운전설계계값을 효과적으로 제어 하면서 기존의 제어로직보다 전력계통상에서 요구되는 발전기 출력을 최대한 신속히 제어하는 과정을 기술하였다. 우선 보일러 마스터와 터빈 마스터, 급수 마스터로 구성된 제어로직을 설계한 뒤 이들 마스터에 대한 발전기 출력, 주증기 압력, 기수분리기 출구온도 각각의 영향을 모델링 기법을 이용하여 적합한 모델을 구했다. 각각의 모델을 고급공정제어기에 적용하고 발전기 출력제어에 대한 기존의 발전소 응답보다 좀 더 효율적이고 실제적용이 가능한 결과를 얻을 수 있도록 튜닝을 시행했으며 그 과정과 결과를 기술했다.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.428-432
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• 1999

Background: It has been shown that low-grade electrical stimulus can transform fatigue resistant muscles which then can be used to protect the heart. The bulky and cumbersome power sources of the artificial heart or implantable ventricular assist devices are still in need of solution; however, on the other hand, the implantable ventricular assist devices using the resistant muscles as the power source have the advantages of using its own muscle contractions. The purpose of this study was to determine the possibility of a clinical application of the skeletal muscle ventricle. Material and Method: Latissimus dorsi muscles (LDM) of 8 canines were used for skeletal muscle ventricle. A latex chamber was wrapped one and a half times with LDM. The chamber was attached to a pressure transducer via Tygon tube. An electrode stimulator was placed around the thoracodorsal nerve and LDM was stimulated in cyclic bursts of 0.31 sec on time and 6.0 sec off time using 3.0 volt Itrel stimulator. The preload volume was added to the system in 25cc increments. Ejection volumes, pressures, and peak power outputs were measured. Result: Ejection volume was 76.3cc with 0cc of preload. Ejection volumes were less than 70ml with increments of preload over 75cc Pressures were more than 107 mmHg when the preloads were less than 75cc and less than 100 mmHg when the preloads were more than 100cc. Peak power output of 16.6 W/kg was observed at 50cc preload. Conclusion: Depending on the changes of preload, the volumes ejected from skeletal muscle ventricle and pressures from the skeletal muscle contraction surpassed those of the normal heart. These data suggest that there are clinical applications for skeletal muscle ventricular assist system.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.323-331
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• 2017

In this paper, four types of deposition control processes such as temperature, pressure, input/output(I/O), and gas were replaced by the Internet of Things(IoT) to analyze the data load and sequence procedure before and after the application of it. Through this analysis, we designed the load balancing in the sensing area of the deposition process by creating the sequence diagram of the deposition process. In order to do this, we were modeling of the sensor I/O according to the arrival process and derived the result of measuring the load of CPU and memory. As a result, it was confirmed that the reliability on the deposition processes were improved through performing some functions of the equipment controllers by the IoT. As confirmed through this paper, by applying the IoT to the deposition process, it is expected that the stability of the equipment will be improved by minimizing the load on the equipment controller even when the equipment is expanded.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.4
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• pp.304-310
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• 2015

Pintle thrusters use pintle stroke to change nozzle throat area, and this controls thrust. Using MATLAB, one-dimensional simulation has been investigated and the results are compared to those of cold flow tests and computational fluid dynamics for the pintle thruster of Chungnam National University. The prediction based on one-dimensional flow theory shows good agreement with measurements for chamber pressure, but deviates for thrust, partly because of nozzle wall separation. Computational results show that nozzle wall separation occurs at an early stage of nozzle expansion, near the design nozzle throat, for the course of pintle strokes. Empirical thrust prediction incorporates nozzle wall separation, and thus 1-D simulation using empirical thrust prediction showed good results for an early stage of pintle stroke.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.143-144
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• 2014

일반적으로 집이나 건물이 지어진 후 약 2~3년이 지나면 수도관 내부에는 물때, 미생물, 유기화합물질 등이 혼합되어 슬라임(slime)이 발생하며, 노후화되어 슬러지(sludge) 형태로 누적 되거나 스케일(scale)이 발생하고 있다. 이러한 이물질의 누적으로 인하여 수도관이 손상되거나, 여러 가지 원인으로 인하여 교체해야하는 상황이 발생할 수 있다. 이러한 이유로 저수조나 공용관의 경우에는 정기적으로 세척하고 있으며, 일반 가정 내의 수도관 역시 정기적인 관리가 필요하다고 볼 수 있다. 본 논문에서는 적절한 배관청소기의 제어를 위하여 물과 압축공기의 배합을 적절하게 제어하도록 하여 배관내부의 이물질을 제거할 수 있는 배관청소시스템을 설계하고자 하며, 밸브조절 및 물의 공급시간과 압축공기의 유입시간에 대한 적절한 제어를 원격지에서 제어할 수 있도록 배관청소시스템을 개발하여 성능에 관한 평가와 사업화 가능성을 제시하고자 한다.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.39-46
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• 2005

Though a fully thermally coupled distillation column-an energy efficient distillation system-consumes less energy, it is not widely implemented in practice due to its operational difficulty. A 3-column distillation system having improved operability is proposed here, and its energy saving performance and application related issues are investigated from the implementation result to a practical hexane process. When an energy integration is employed, the proposed system requires 18% less energy than a conventional 2-column system, which is found from the HYSYS simulation. Though more control loops than the 2-column system are required, the proposed system has better controllability of product compositions and the pressure control of the system is easier.