• 한국농공학회지
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• 제8권1호
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• pp.1011-1034
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• 1966

This thesis is the final report which has long been studied by the author to obtain the design basis for various hydrological constructions with the specific system suitable to the natural environmental conditions in Korea. This report is divided into two parts: one is to estimate runoff volume from watersheds and the other to estimate the peak discharge for a single storm. According to the result of observed runoff record from watersheds, it is known that Kajiyama formula is useful instrument in estimating runoff volume from watersheds in this country. But it has been found that this formula shows us 20-30% less than the actual flow. Therefore, when wihed to bring a better result, the watershed characteristics coefficient in this formula, that is, f-value, should be corrected to 0.5-0.8. As for the method to estimate peak discharge from drainage basin, the author proposes to classify it in two ways; one is small size watershed and the other large size watershed. The maximum -flood discharge rate $Q_p$ and time to peak Pt obtained from the observed record on the small size watershed are compared by various methods and formulas which are based upon the modern hydrological knowledge. But it was fou.d that it. was not a satisfied result. Therefore, the author proposes. tocomputate $Q_p$, to present 4.0-5.0% for the total runoff volume ${\Sigma}Q$.${\Sigma}Q$ is computed under the assumption of 30mm 103s in watershed per day and to change the theoritical total flow volume to one hour dura tion total flow rate when design daily storm is given. Time to peak Pt is derived from three parameters which are u,w,k. These are computed by relationship between total runoff volume (ha-m unit)and $Q_p$. (C.M.S. unit). Finally, the author checked out these results obtained from 51 hydrographs and got a satisfied result. Therefore the author suggested the model of design dimensionless unit-hydrograph. And the author believes that this model will be much available at none runoff record river site. In the large size watersheds in Korea when the maximum discharge occurs, the effective rainfall is two consequtive stormy days. So the loss in watershed was assutned as 6Omm/2days,and the author proposed 3-hour-daration hydrograph flow distribution percentage. This distribution percentage will be sure to form the hydrograph coordinate.

• 대한토목학회논문집
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• 제29권5B호
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• pp.419-427
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• 2009

기존의 WTP를 이용한 수질개선 관련 편익산정 연구들은 특정 하천에 대하여 '모든 종류의 물놀이 가능한 2급수로 개선', '수영가능수준으로 개선' 등을 설문대상으로 하여 지불의사를 산정한 다음, 해당 유역의 가구수를 곱하여 편익으로 산정하였다. 이는 특정 수자원개발사업에 대한 편익이 아니며, 설문작성 과정에서 수질개선 정도에 대한 객관적인 설명이 부족하고, 단순화되었기 때문에 설문응답자들에게 설문대상재화에 대한 정보를 전달하는데 미흡한 점이 있었다. 따라서 본 연구에서는 수자원개발사업시 상수도 원수수질개선에 대한 편익/비용분석에 적용할 수 있는 편익산정방법론을 제시하였다. 본 연구에서는 수도권을 대상으로 하여 용수를 사용하는 소비자의 BOD 개선정도별 지불의사(WTP)를 설문을 조사하고, 설문결과를 통계분석하여 수질개선-지불의사 관계식을 도출하였다. 사례연구로서 낙동강수계의 내성천 지방2급하천 구간에 계획한 송리원 다목적댐을 대상으로 적용하였다. 방류시나리오별 연평균편익산정 결과, 연평균계획방류량($4.79m^3/s$) 방류시 5,980 백만원, 풍수기(7~10월)를 제외한 기간의 계획방류량($7.22m^3/s$) 방류시 8,663 백만원, 수질악화기 계획방류량($10.72m^3/s$) 방류시 11,905 백만원, 최대계획방류량($13.54m^3/s$) 방류시 14,502 백만원으로 산정되었다. 본 연구에서 개발된 가구소득별 수질개선 (BOD)-지불의사(WTP) 관계식을 이용함으로써 수질개선사업에 대한 원수수질편익을 산정할 때 수질개선정도에 상관없이 쉽게 편익을 산정할 수 있을 것으로 판단된다.

• 한국한의학연구원논문집
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• 제16권3호
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• pp.53-66
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• 2010

This study focuses on the contents about the Urinalysis which is the most representative one of the Tibetan medicine. Also, this study compares it with the Urinalysis of Traditional Korean medicine. This study focuses on the simple history, the theoretical system, the diagnosis and the urinalysis mainly based on the documents related to the Tibetan medicine. Also, through the comparison with the contents of textbook of Traditional Korean Medicine and the urinalysis shown in the Dongeuibogam(東醫寶鑑) which is the representative Korean medical book, the difference between Tibetan Medicine and Traditional Korean Medicine will be observed. The contents related about the urinalysis of the Tibetan medicine are more specific than those of Traditional Korean Medicine. By observing the color, scent, vapor and sediment of one's urine together with periodic changes more thoroughly, it is possible to find out the cause of a certain disease. However, Traditional Korean Medicine examines the medical conditions mainly based on the state of discharge and fever, showing a clear difference. The Tibetan medicine has an extremely specific type of urinalysis in comparison with that of Traditional Korean Medicine. It is the only characteristic of the Tibet medicine, which cannot be found in any other traditional medicine. By applying the viewpoint of the doctor who diagnoses the patient by measuring his or her pulse, it is possible to make the diagnosing process more specific and accurate. It is expected that the follow-up study will be continuously executed with the introduction of the system for the urinalysis of the Tibetan medicine to Traditional Korean medicine.

• KIEE International Transactions on Electrophysics and Applications
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• 제4C권2호
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• pp.55-59
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• 2004

Throughout manufacturing processes, pulse shaping is required for material processing and it is regarded as an important (actor according to the specific characteristics of materials. Therefore, this study suggests a highly appropriate pulse shaping technique using a multi-switching method. This is a pulse superposition method in which one flash lamp can consecutively turn on by the double switching of the discharging system. It is possible to construct a variety of pulse shapes and pulse widths by the consecutive trigger of the silicon-controlled rectifiers (SCR) of a PIC (program integrated circuit) one-chip microprocessor. The use of this technique can provide a number of advantages to people who require suitable pulse shaping for particular applications such as welding, cutting, and drilling.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1228-1232
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• 2010

The nanocomposites of polypyrrole (PPy) and multi-walled carbon nanotube (MWCNT) with different composition are synthesized by the chemical oxidative polymerization method. In these composites, the MWCNTs are uniformly coated by PPy with different thickness. The electrochemical properties of the composite electrodes are investigated by cyclic voltammetry, galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy. The full cells assembled with the PPy/MWCNT composite electrodes deliver initial specific capacitances ranging from 146.3 to 167.2 F/g at 0.5 mA/$cm^2$ and exhibit stable cycling characteristics. The effect of content of MWCNT in the composite on cycling performance of the cells is also investigated.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.133.1-133.1
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• 2010

In this work, carbon black(CBs)-embed multi-walled carbon nanotubes (MWNTs) as conductive fillers for activated carbon(ACs)-based electrodes for supercapacitor were prepared by chemical reduction of oxidized MWNTs and CBs. The effect of CBs-MWNT composites on electrochemical performances of ACs-based electrodes were investigated as a function of CB-MWNT ratio. It was found that CBs-MWNTs composites were formed by the reduction reaction of the functional groups of oxidized MWNTs and CBs. It was resulted in the conjugation of CBs onto the MWNT having high surface area and aspect ratio, leading to the enhanced electrical properties of MWNTs. The electrochemical performances, such as current density, charge-discharge, and specific capacitance of the ACs/CBs-MWNT electrodes were higher than that of ACs/MWNTs and conventional ACs/CB electrodes, which was attributed to the synergistic effect of CBs-MWNTs as a conductive filler.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.194-194
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• 2010

The variable demand on the energy market, as well as the limited energy storage capabilities, requires a great flexibility in operating hydraulic turbines. But, present in Korea, the absence of testing laboratories and technical criteria for the performance test of small hydropower degrades the efficiency of the domestic hydropower machines, A performance guarantees for hydro turbines shall be contain, as a minimum, guarantees covering power, discharge and specific hydraulic energy, efficiency, maximum momentary overspeed and maximum momentary pressure and/or maximum steady-state runaway speed, as well as guarantees related to cavitation. Performance test are conducted by the test standard. Test codes based on extensive research data are written under the leadership of an IEC. Performance evaluation is carry out several test(performance test, cavitation test and runaway test). The paper presents the international turbine test laboratory and performance test standard.

• 한국전기전자재료학회논문지
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• 제33권1호
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• pp.70-77
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• 2020

In this study, the sterilization property of E. coli was established using a plasma generator with a flexible electrode structure. The bacterial suspension was prepared based on the McFarland standard 0.50 (1.5×10⁸ CFU/mL) concentration and a specific amount was inoculated on the plate medium. After the plasma was discharged 3 cm away from the plasma generator in the range of 30s to 5 min and the results compared to the control group, the observed colonies that were formed decreased significantly as the plasma discharge time increased.

• Journal of Electrochemical Science and Technology
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• 제6권3호
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• pp.81-87
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• 2015

This study introduces a facile strategy to prepare metal oxide/conducting polymer nanocomposites that may have promising applications in energy storage devices. Ploy aniline/nano wire manganese dioxide (PANI/NwMnO₂) was synthesized by cyclic voltammetry on glassy carbon electrode. Morphology and structure of the composite, pure PANI, MnO₂ nanowires were fully characterized using XRD and SEM analysis. Electrochemical studies shows excellent synergistic effect between PANI and MnO₂ nanowires which results in its capacitance increase and cycle stability against PANI electrode. Specific capacitances of PANI/NwMnO₂ and PANI were 456 and 190 F/g respectively. The electrochemical performance of electrodes studied using cyclic voltammetry, Galvanostatic charge/discharge and impedance spectroscopy.

• 전기학회논문지
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• 제59권1호
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• pp.65-69
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• 2010

Supercapacitors as novel energy storage devices between conventional capacitors and batteries, with more specific capacitance and energy densities than conventional capacitors and more power densities than batteries are to be used in many fields. And, social demand on fuel economy and reducing pollution needs equipment of new function such as energy storage system with good power performance, high cyclability and good energy efficiency. Supercapacitor is regarded as one of good alternatives for meeting the requirement of market with excellent power performance and high cyclability. This paper deals with the fundamental characteristics of supercapacitor unit and charge and discharge behavior of supercapacitor module for developing 42V hybrid energy storage system with lead acid battery and supercapacitor in order to adopt to 42V power net for vehicle.