한강 상류유역의 강우강도에 따른 수위 예측 연구

최한규,조현종,백효선 江原大學校 産業技術硏究所 2010 産業技術硏究 Vol.30 No.B

Recently, there has been enormous damage due to river floodings caused by localized heavy rains. The direct discharge triggered by those torrential rains inflicts severe property damage on the residents of nearby areas. To minimize the possibility of river floodings in case of heavy rains and to predict the possible damage, the management of existing rainfall and water level observatories should be checked and prediction methods based on the characteristics of water usage and floodgate of nearby rivers must be further analyzed. Therefore, this research analyzed the water level change predictions on different spots with a regression equation of rainfall and water levels, using the observation data of the water level observatory in Jeongseon-gun, Gangwon Province and the rainfall observatory which are located on the upper region of the Han river.

스테인리스강 소결체를 이용한 치과용 임플란트 개발(Ⅰ) : 치과용 소결체의 제작과 물성을 중심으로 Fabrication and Physical Properties of Sintered Stainless Steel

최한철,고영무,모웅남 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.3

The first factor to decide the success of dental implantation is sufficient, osseointegration between implant fixture and its surrounding bone tissue. Thus many studies about this have been under actively. In recent, one of them is to increase the roughness of the surface of an implant fixture by treating the surface of an implant fixture in various ways, increase the contact area between an implant fixture and its surrounding bone tissue and so induce a sufficient osseointegration between them. The roughness of the surface on an implant fixture can be increased by coating the smooth surface of an implant fixture with hydroxyapatite or titanium particles or by treating the surface with acid. But these ways can cause the failure of implantation in the long run due to the separatation of coated particles from an implant fixture and sometime; can't attain the sufficient osseointegration because of emitting ion into the surrounding bone tissue. To develop dental implant materials, fabrication and physical properties of sintered stainless steel have studied using hardness tester, tensile tester, SEM, TEM, EPMA, EDX. Stainless steel compacts containing Cu (2-10 wt%) were prepared either by electroless Cu-plating method which result in the increased homogenization in alloying powder or by Cu-elemental powder addition method on the stainless steel powder Experimental investigation foucusing on mechanical property was performed for Cu-added samples to study the effects of Cu content, electroless Cu-plating method, and Cu-elemental powder addition method on the surface characteristics of sintered stainless steel in Mo and Cu in sintered stainless steel on the mechanical behaviors. Microstructural characterization revealed that Cu-addition by electroless Cu-plating method resulted in less porous material compared that prepared by Cu-elemental powder addition method. Since Cu is blown to be effective in reducing the precipitation of chromium carbide at sensitization temperature, Cr concentration in electroless Cu-plating method was uniformly distributed in the grain boundary and in the matrix. The sintered density in electroless Cu-plating method increased with reducing porosity as a result of the Cu-uniform distribution due to electroless Cu plating during the sintering process. The amount of Cu added in the sintered stainless steel affected significantly tensile strength which increased with 4 wt% Cu and decreased with more than 7 wt% Cu.

전력계통의 고조파 실태조사를 위한 설문서 설계에 관한 연구

최규하,신중린,임한석 建國大學校 附設 産業技術硏究所 1993 논문집 Vol.18 No.-

A design of survey form is studied for the investigations of technical aspects and/or social effects caused by harmonics on the electric power system of Korea. The survey form is aimed to have the function of investigation for the current status of harmonics problems on the power system, as well as the function of giving further understanding of the problems to the field engineers and customers in related sphere. The proposed survey form will give some contribution to build up nation-wide countermeasures to the harmonics problems.

Steinbeck의 작품에 나타난 긍적적 비전

최한용 조선대학교 외국문화연구소 1994 外國文化硏究 Vol.17 No.1

20세기 말에 접어 들며 포스트모던을 비롯한 기존의 가치체계를 부인하는 새로운 사조가 범람하여 기계화와 전산화로 말미암은 정신문화의 빈곤현상은 더욱 가속화되고 있는 듯하다. 따라서 인간의 모습이 더욱 왜곡 되고 있으며, 또한 소외 내지는 고립화 현상이 심화되고 있다. 아울러 각종 사회의 병리현상이 심각해지는 작금의 세태는 인간의 존엄성을 확신할 수 있는 분멸의 가치를 갈망하게 한다. 이러한 때일수로 우리는 예술 또는 참문학의 효과를 인식하게 되고 그 세계로 눈을 돌리게 된다.

非競爭 政黨體系에 관한 小考

崔漢秀 건국대학교 1985 政法論叢 Vol.20 No.1

전류형 능동 전력필터를 위한 델터변조기법에 관한 연구

최규하,백형래,김한성 建國大學校 附設 産業技術硏究所 1992 논문집 Vol.17 No.-

Delta modulation technique for current-type active power filter is proposed which can not only eliminate the harmonic current but compensate the reactive power at the AC sides where the nonlinear loads are connected. The delta modulated current control can be used to improve both the response and the control capability of the injected compensating current for the active filter with constant current source. As a result the compensated ac line current becomes nearly sinusoidal and also the input power factor is improved roughly to unity.

능동전력필터를 위한 새로운 전류제어 델타변조방식에 관한 연구

최규하,김한성,강병희 건국대학교 1996 學術誌 Vol.40 No.2

Advances of Power Electronics in industrial domains lead to continuous increase of harmonics on net-works. To solve these problems, Active Power Filtering(A.P.F.) concept has been developed for several years. This paper describes an A.P.F. comprising Current Source Inverter (CSI) by Current-Controlled Delta-Modulation Technique. This Concept is applied to a new current source Sigma-Delta Modulation(SDM) inverter for A.P.F. As associating this concept with current source inverter(CSI) APF, there are several advantages. Most of all, this controller can be easily implemented and has a satisfactory compensating performance. In addition, inverter output fitter, the capacitor and inductance size are considerably reduced. The controller is implemented by analog circuit and one-chip micro-processor(TMS370C756). As the typical load which generates the harmonics, a 3-phase diode rectifier is used, The proposed scheme is investigated by digital simulation(ACSL). Also, the theoretical results is verified by analog & digital experiment.

한국정당의 합당에 관한 연구 : 합당과 선거시기 및 정당의 세력을 중심으로

최한수 建國大學校 社會科學硏究所 1998 社會科學論叢 Vol.3 No.-

치과용 자성 어태치먼트 재료의 안정성 개선에 관한 연구 : II.질화티타늄 코팅이 치과용 자성재의 내식성에 미치는 영향 Ⅱ.Effect of TiN Coating on Corrosion Resistance of Dental Magnetic Materials

최한철,고영무,정재헌,신종연,김일선,최성욱,정효수 대한치과기재학회 1999 대한치과재료학회지 Vol.26 No.4

Dental magnetic materials have been applied to removable prosthetic appliances, maxillofacial prostheses, obturator and dental implant but they still have some problems such as low corrosion resistance in oral environments. To increase the corrosion resistance of dental magnetic materials, surfaces of Sm-Co and Nd-Fe-B based magnetic materials were plated with TiN and then electrochemical corrosion test were performed in 4 kinds of electrolyte solutions(0.9% NaCl. 1% lactic acid, 0.05% HCl and modified Fusayama's artificial saliva). From this study, corrosion behavior, amount of elements released, mean average surface roughness values and the changing of mean surface microhardness values were measured comparing with control group of non-sputtered plating magnetic materials. The results were as follows: 1. TiN layer coated on magnet grows into preferred direction with lamellar structure and its thickness is 3.0㎛. 2. Sm-Co base magnetic materials coated with TiN have good corrosion resistance in 1% lactic acid and their pitting corrosion can not be seen. 3. Nd-Fe-B base magnetic materials coated with TiN showed good tendency of corrosion resistance in 0.05% HCl solution. 4. The amount of elements released from both Sm-Co and Nd-Fe-B base magnetic materials coated with TiN were more significantly decreased than that of uncoated magnetic materials. 5. The mean surface roughness values of both Sm-Co and Nd-Fe-B base magnetic materials coated with TiN were smooth than that of uncoated magnetic materials after corrosion test. 6. The decreasing rate of microhardness of both Sm-Co and Nd-Fe-B base magnetic materials coated with TiN were lower than that of uncoated magnetic materials after corrosion test. 7. Dental magnetic materials coated with TiN produced various corrosion products such as TiO, TiO₂, Ti₂O₃on the surface and resulted in better corrosion resistance than uncoated magnetic materials. In conclusion, it is considered that the corrosion problem of dental magnetic materials could be solved to some extent by EB-PVD with TiN on the surface of dental magnetic materials.

치과용 임플란트로 적용을 위한 스테인리스강 표면의 Ti/TiN film 증착

최한철,고영무,백대화,박영록,박지윤 대한치과기재학회 1999 대한치과재료학회지 Vol.26 No.1

A study on Ti/TiN film coating on stainless steels for application as dental implants have been investigated. The stainless steels containing Ti were solutionized 1050℃ for 1hr. Then the surface was deposited with Ti and TiN by using electron-beam deposition method. The deposited layer and microstructure were analyzed by using XRD, WDX, XPS and SEM. The hardness and wear resistance of deposited surface were examined and corrosion behavior were investigated by using potentiostat, XPS and SEM. The results were as follows: 1. Some defects showed on the deposited surface, such as crater and microdroplet, and surface roughness increased in all specimen after TiN deposition. 2. Ti/TiN deposited layer showed columnar structure which nucleated and grew on the special crystalline direction and plane: Ti/TiN layer TiN(220) and TiN(200). 3. The hardnesses of Ti/TiN layer was higher than that of TiN layer. 4. In case of stainless steel containing high Ti content, Ti/TiN layer showed better wear resistance than that of TiN layer. 5. Pitting potential of TiN film in NaCl solution increased as Ti content increased, but pitting potential of Ti/TiN film were not affected by the Ti content of substrate. Pitting potential of Ti/TiN film showed high value than that of TiN film in NaCl solution. The number and size of pits were apparently decreased by Ti/TiN film deposition on the stainless steel.