• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.499-504
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• 2001

A validation of a 3D CFD model for predicting local subcooling of moderator in the vicinity of calandria tubes in a CANDU reactor is performed. The small scale moderator experiments performed at Sheridan Park Experimental Laboratory(SPEL) in Ontario, Canada[1] is used for the validation. Also a comparison is made between previous CFD analyses based on 2DMOTH and PHOENICS, and the current model analysis for the same SPEL experiment. For the current model, a set of grid structures for the same geometry as the experimental test section is generated and the momentum, heat and continuity equations are solved by CFX-4.3, a CFD code developed by AEA technology. The matrix of calandria tubes is simplified by the porous media approach. The standard $k-\varepsilon$ turbulence model associated with logarithmic wall treatment and SIMPLEC algorithm on the body fitted grid are used and buoyancy effects are accounted for by the Boussinesq approximation. For the test conditions simulated in this study, the flow pattern identified is a buoyancy-dominated flow, which is generated by the interaction between the dominant buoyancy force by heating and inertial momentum forces by the inlet jets. As a result, the current CFD moderator analysis model predicts the moderator temperature reasonably, and the maximum error against the experimental data is kept at less than $2.0^{\circ}C$ over the whole domain. The simulated velocity field matches with the visualization of SPEL experiments quite well.

• Journal of Advanced Marine Engineering and Technology
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• 제36권4호
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• pp.430-436
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• 2012

본 연구에서는 납축전지가 장착된 소형 전기자동차의 여러 가지 주행 특성에 따른 배터리의 전압강하를 실증실험을 통하여 측정하였다. 실험을 통하여 2인승의 소형전기자동차의 에너지 소비량을 평가하고 주행거리 등을 점검하기 위하여 속도별 주행특성과 주행 중에 난방장치를 가동하였을 경우에 감소하는 주행거리를 평가하였다. 전기자동차의 주행속도는 10km/h에서 20km/h씩 증가시키면서 히터의 가동유무에 따른 에너지 소비량을 측정하였다. 실험결과 본 실험용 소형 전기자동차의 에너지효율이 가장 높은 경제속도는 35km/h로 나타났으며, 일회 충전으로 경제속도로 주행할 경우에 약 75km의 거리를 주행할 수 있으며, 일반적인 주행의 경우에는 약 58km를 주행할 수 있다. 또한 난방장치를 최대로 가동할 경우에는 약 35%의 에너지 소비가 증가하는 것을 알 수 있다.

• 건축역사연구
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• 제21권1호
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• pp.119-134
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• 2012

Balhae(698~926) was the ancient state which opened the Nambuk-guk period with the Unified Silla. But Balhae architecture began to included in the history of Korean architecture only about 15 years ago, such as the books written by Yun Jang-seop or Ju Nam-cheol. I discussed four issues related to Balhae architecture in this paper. First, I criticized the excavation report of 24 stones remains at Jiangdong in Duhua city, and I asserted the ondol site belonged to different period. Second, I also interpreted that the building found on the tombs no.13 and no.14, in the Longhai burial area in Helong city must be a wooden stupa. Third, Balhae played some important roles in the history of ondol. It developed Koguryeo ondol in terms of structure, gave an opportunity to the ruling class to adopt ondol for the first time, and passed the heating system down to the Jurchen, the ancestor of the modern Manchurian. Fourth, the Russian-Korean joint research team excavated seven building sites in Koksharovka 1 fortress from Russian territory these four years, and it is reasonable to assume the fortress was the center of Anbyeon-bu, one of 15 local government districts in Balhae. I guess this buildings were the royal shrine built by resisters after the fall of Balhae, and the vessel stands found there must be used for ancestral memorial ceremony inside them.

• Journal of Advanced Marine Engineering and Technology
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• 제19권4호
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• pp.17-26
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• 1995

In general existing air conditioning devices, which are carried out by convection heat transfer, are very popular compared with the radiation type air conditioning devices. But perconal convection tpe air conditioning units are unuseful air conditioning type because it handles amount of surrounded air to meet the temperature and humidity. In this view, this study is intended to develope personal dir conditioning units using a radiation type radiator. Liquid Droplet Radiator(L.P.R.) radiates the energy by means of thermal radiation. Radiative energy from L.P.R. is the infrared rays which heat the objects without lose of energy. It is a desirable heating method for the local area within the large room. In this study, the analysis uses the Monte Carlo methd to predict the temperature distribution in the droplet sheet and the net heat flux from the L.D.R.. And for this study and experiment was carried out to analyse the radiative and convective heat transfer characteristics in the L.D.R.. And the experiment was investigated the effects of inlet temperature, feed rate, optical thickness and droplet diameter on heat transfer characteristics of L.D.R.. The obtained results from the numerical and experimental studies of L.D.R. were as follows ; (1) The heat flux of L.D.R. was effected by extinction coefficient of droplet sheet, optical thickness and droplet temperature, surface area and emissivity of the droplet. And it was increased with the temperature, feed rate and optical thickness, on the other hand decreased with increasing of droplet diameter. (2) The experimental results for heat flux was ecalucted below 20% than that of the numerical solution by Monte Carlo method, but the tendency of the variation shows relatively good agreement.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.353-353
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• 2014

본 연구에서는 Sputter를 이용하여 Room Temp.에서 증착된 NbOx 박막의 열처리에 따른 결정도를 분석하고, 이러한 결정도의 변화가 Metal Insulator Transition특성에 의한 Threshold switching에 어떠한 영향을 미치는 지에 대하여 연구하였다. NbOx 박막의 threshold switching 특성 분석을 위해, 1.4um의 TiN 위에 15nm의 NbOx를 증착하고 Top Electrode로 Pt를 증착하여 측정하였다. 증착된 NbOx는 Nb metal target으로 Reactive Sputter를 이용하여 Room Temp.에서 증착하였으며, 조성은 Partial Oxygen Pressure를 이용하여 조절하였다. 증착된 박막의 결정도는 TEM 및 XRD를 통하여 분석하였고 조성은 XPS를 이용하여 분석하였다. Sputter로 NbOx 증착 시 Partial Oxygen Pressure에 따른 조성을 XPS로 확인한 결과, Partial Oxygen Pressure 2%에서 NbOx의 조성을, 5%이상일 경우, Nb2O5의 조성을 가지는 것으로 확인되었다. Partial Oxygen Pressure 2%에서 증착한 NbOx 박막의 열처리에 따른 결정도를 분석한 결과, As-Dep상태에서는 amorphous상태였다가 600'C이상으로 1분간 열처리를 하였을 때 NbOx의 결정도가 증가함을 확인하였다. I-V 특성 측정 결과, 열처리 온도가 증가함에 따라 initial current가 점진적으로 증가하는 경향을 보이는데, 이는 열처리 시 amorphous상에서 poly-crystalline으로 미세구조의 변화가 일어나면서 grain boundary가 생성되며 생성된 grain boundary를 통해 leakage current가 증가하는 것으로 추측된다. 또한, 결정도가 증가함에 따라 electro-forming voltage가 감소하는 경향을 보이며 안정된 threshold switching 특성을 보이고 있다. 특히, 700'C 1분간 열처리 시에는 electro-forming 과정이 없이 threshold switching이 나타나는 현상이 관찰되었다. 이로 미루어 보아, threshold switching에서 나타나는 forming 현상은 local joule heating에 의해 박막이 결정화 되는 과정으로 추측된다. 결론적으로, 박막의 결정도가 initial current 및 Threshold switching 특성에 큰 영향을 미치는 것으로 예상된다.

• Progress in Superconductivity
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• 제7권2호
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• pp.114-119
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• 2006

High critical current density, high n value, multiple faults endurances, and fast recovery characteristics of YBCO thin films are very attractive characteristics for developing resistive type superconducting fault current limiters. But due to the limited current and voltage ratings of one YBCO module, it is needed to construct series and parallel module connections for high capacity electric networks. Especially for distribution network, more than 30 units should be connected in series to meet voltage level. So in order to construct distribution-level superconducting fault current limiter, simultaneous quench in one YBCO thin films should be realized, and furthermore, quench should be occurred in all fault current limiting units equally to avoid local heating and failures. In this paper, we proposed optimum design of YBCO thin films for fault current limiting module and technical method using shunt resistor to achieve simultaneous quench between multi current limiting units. From the analytical and the experimental results, optimal current path and thickness of shunt material was determined for YBCO thin films and shunt resistor between modules was developed. Finally, 14 kV one phase resistive fault current limiter using multi YBCO thin films was constructed and it was possible to get satisfactory test results.

• The Journal of Korean Physical Therapy
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• 제16권4호
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• pp.23-37
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• 2004

Fibromyalgia syndrome(FMS) is a chronic pain disorder of unknown etiology characterized by widespread musculoskeletal aches and pains, stiffness, and general fatigue, disturbed sleep and sleepiness. Frequently misdiagnosed, FMS is often confused with myofascial pain syndrome, polymyalgia rheumatica, polymyositis, hypothyroidism, metastatic carcinoma, rheumatoid arthritis (RA), juvenile rheumatoid arthritis, chronic fatigue syndrome, or systemic lupus erythematosus, any of which may occur concomitantly with FMS. The management of FMS often begins with a thorough examination and a diagnosis from a physician who is formally trained in tender-point/trigger-point recognition. An initial diagnosis provides reassurance to the patient and often reduces the anxiety and depression patterns associated with FMS. The most common goals in the management of FMS are (1) to break the pain cycle, (2) to restore sleep patterns, and (3) to increase functional activity levels. Because FMS is a multifactorial syndrome, it is likely that the best treatment will encompass multiple strategies. Medication with analgesics and antidepressants and also physiotherapy, are often prescribed and give some relief. The other most effective intervention for long-term management of FS to date is physical exercise. Physical therapists can instruct patients in the use of heat at home (moist hot packs, heating pads, whirlpools, warm showers or baths, and hot pads) to increase local blood flow and to decrease muscle spasm and tension. Also instruct patients in the proper use of cold modalities (ice packs, ice massage, and cool baths) to anesthetize localized areas of pain (tender points) and break the pain cycle. Massage and tender-point massage also may promote muscle relaxation. To date, the two most important interventions for the long-term management of FS are patient education and physical exercise. Lately, is handling FMS and Chronic Fatigue syndrome(CFS) together, becuase FMS and CFS are poorly understood disorders that share similar demographic and clinical characteristics. Because of the clinical similarities between both disorders it was suggested that they share a common pathophysiological mechanism, namely, central nervous system dysfunction.

• 한국환경과학회지
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• 제15권10호
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• pp.919-928
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• 2006

The present study applied an atmospheric flow field model in Gwangyang-Bay which can predict local sea/land breezes formed in a complex terrain lot the development of a model that can predict short term concentration of air pollution. Estimated values from the conduct of the atmospheric flow field were used to evaluate and compare with observation data of the meteorological stations in Yeosu and the Yeosu airport, and the effect of micrometeorology of surround region by the coastal area reclamation was predicted by using the estimated values, Simulation results, a nighttime is appeared plainly land breezes of the Gwangyang-bay direction according to a mountain wind that formed in the Mt. of Baekwooun, Mt. of Youngchui. Land winds is formed clockwise circulation in the north, clockwise reverse direction in the south with Gangyang-bay as the center. Compared with model and observation value, Temperature is tend to appeared some highly simulation value in the night, observation value in the daytime in two sites all, but it is veil accorded generally, the pattern of one period can know very the similarity. And also, wind speed and wind direction is some appeared the error of observation value and calculation results in crossing time of the land wind and sea land, it can see that reproducibility is generally good, is very appeared the change land wind in the nighttime, the change of sea wind in the daytime. And also, according to change of the utilization coefficient of soil before and after development with Gwangyang-Bay area as the center. Temperature after development was high $0.55\sim0.67^{\circ}C$ in the 14 hoots, also was tend to appear lowly $0.10\sim0.22^{\circ}C$ in the 02 hours, the change of u, v component is comparatively tend to reduced sea wind and land wind, it is affected ascending air current and frictional power of the earth surface according to inequality heating of the generation of earth surface.

• 천문학회보
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• 제39권1호
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• pp.63.2-63.2
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• 2014

As a part of the "Dust, Ice, and Gas In Time" (DIGIT) key program on Herschel, we observed GSS30-IRS1, a Class I protostar located in Ophiuchus (d =125 pc), with Herschel/Photodetector Array Camera and Spectrometer (PACS). More than 70 lines were detected within a wavelength range from 50 ${\mu}m$ to 200 ${\mu}m$: CO lines from J = 14-13 to 41-40, several $H_2O$ lines of Eup = 100 K to 1500 K, 16 transitions of OH rotational lines, and two atomic [O I] lines at 63 and 145 ${\mu}m$. The [C II] line, known as a tracer of externally heated gas by the interstellar radiation field, is also detected at 158 ${\mu}m$. All lines, except [O I] and [C II], are detected only at the central spaxel of $9^{\prime\prime}.4{\times}9^{\prime\prime}.4$. The [O I] emission is extended along a NE-SW orientation, which is consistent with the known outflow direction, while the [C II] line is detected over all spaxels. One possible explanation of the detection of the [C II] line and no correlation of its spatial distribution with any other molecular emission is the existence of the enhanced ISRF nearby GSS30-IRS1. One interesting feature of GSS30-IRS1 is that the continuum emission is extended beyond the point-spread function (PSF), unlike the molecular line emission, indicative of significant external heating. The best-fit continuum model of GSS30-IRS1 with the physical structure including flared disk, envelope, and outflow shows that the internal luminosity is 11 $L_{\odot}$, and the region is also externally heated by a radiation field enhanced by a factor of 25 compared to the local standard interstellar field.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.229-234
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• 2008

The new millennium has started with several innovations driven by fast evolution of the technologies in energy sector. A strong impulse towards the diffusion of new economical efficient technologies regulatory incentives related to energy production from renewable source and a small scale building trigeneration and to promotion of more sustainable environmental-friendly generation solutions, the evolution of electricity markets, more and more binding local emission constraints, and the need for improving the security of supply to reduce the energy system vulnerability. The 24 percentage energy quantify of total energy consumption consumes in commercial buildings and residential houses and the 30% portion of total $CO_2$ emissions covers also in the commercial buildings and residential houses sector. To cope with efficiently this energy sinuation in building sector, Building microgrid or building tooling, heating & power(BCHP) system has been interested in recent day due to meeting thermal and electric energy requirements efficiently and with appropriate energy quality. A multi agent system is a collective of intelligent agents that communicate with each other and work cooperatively to achieve common goals. Also, it is to medicate and coordinate communication between Control Areas and Security Coordinators for teal-time control of the BCHP system and the power pid. In this new circumstance, it is very important to integrate the power and energy delivery system and the information system(communication, networks, and intelligent equipment) that controls it. Therefore, development of smart control modules with open communication protocol and seamlessly interchange the data and information between control network and data network including extranet and intranet give a great meanings. We designed and developed the TCP/IP-CAN IED agent modules and ModBus./LonTalk/(TCP/IP) IED agent ones to configure the multi-agent system based smart energy network of commercial buildings and also intelligent algorithms for inverter fault diagnostics which ran be operated in control level or agent level network.