• Journal of Construction Engineering and Project Management
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• 제6권1호
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• pp.11-19
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• 2016

Most of the Indian contractors are not well equipped to handle the growing demand of infrastructure development; hence construction projects frequently run in to time and cost overruns, disputes and quality issues. This study aims to improve the construction industry in India by implementing lean principles to eliminate non-value adding activities (wastes). The purpose of this study is to 1) identify the wastes and their sources affecting the construction process, and 2) to identify problems and document lessons by applying a Last Planner System (LPS) to a sample project. First, the researchers identified that Delays, Rework, and Interruptions were the most critical wastes affecting the construction process and Poor management control, Poor Planning and Shortage of Resources were the major sources of the above mentioned wastes. Second, the researchers report the Percent of Planned Complete (PPC) analysis results and experienced problems after implementation of LPS at the sample project. It was observed that much more improvement could have been achieved if there was consensus between the owners and the contractor on the implementation of the LPS in its entirety. Some of the problems experienced in the implementation of the LPS like lack of scheduling, resource and material shortage were found to be similar to those in developed countries.

• 건축사
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• 3호통권359호
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• pp.90-95
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• 1999

WTO 세계무역기구의 발족과 더불어 국가간의 개방과 정책에 따라 건설시장은 물론 사회 전 분야에 걸쳐 새로운 시도가 이루어지고 있다. 건축 관련 부분은 민간사업뿐 아니고 정부 조달시장까지도 개방되어 정부부처나 지방 자치단체에서 구매하는 물품(설계 및 시공 포함)에 외국업체가 참여하고 있는 실정이다. 그러나 건축 설계의 경우 "서비스 무역에 관한 일반 협정"에 의해 원칙적인 기준만 체결되어 있을 뿐 상호인증에 관한 세부사항은 서로의 제도가 동일하거나 합의한 나라를 제외하고는 당사국간의 상이한 제도와 운영체제로 인하여 실용화되고 있지 않고 있다. 국내에서는 지난 4년간 "국가를 상대로 하는 계약에 관한 법률"을 제정하고 건설제도 기획단을 운영하여 시장개방에 대처해 왔으나 국제적인 건축 설계 관련 단체인 UIA와는 의견 교환이 없었다. 특히 상호인증에 따른 기본 요건으로 대두되고 있는 건축교육, 실습 및 훈련, 건축사 자격 등에 대한 우리의 입장을 정리하여 국제적으로 대응할 필요성이 요구되고 있으며 건축설계 관련자들에게 매우 중요한 관심사의 하나로 되어 있다. 따라서 이러한 문제를 논의하기 위해 국제건축가연맹(UIA)에서는 용역실무협의회를 설치하여 이미 2년여에 걸쳐 인정방법에 대한 세부사항을 검토하고 있으며, 올해(6월) 북경 총회에서 상호인정 표준안을 공포할 예정이다. 이와 관련하여 건축3단체(대한건축사협회, 대한건축학회, 한국건축가협회)주관으로 건축사자격 상호인정에 대한 공동 대응책을 논의하고자 건축계와 정부가 함께 참석하여 토론회를 개최한 바 있으며, 또한 본협회 국제위원회에서 한국측을 대표하여 지난 98년 12월에 열린 UIA 용역실무위원회(PPC)에 참석하여 상호인정에 대한 우리측 입장을 개진한 바 있다. 이에 본지에서는 문호 개방에 따른 한국건축의 현안에 대한 현실적이고 구체적인 문제점이 검토되고 아울러 우리 건축계의 입장 정리와 실질적인 의견을 수렴하고자 UIA 국제 표준안 전문에 이어 부록을 정리하여 게재한다

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.278-278
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• 2016

Solution-processed metal-oxide semiconductors have been considered as the next generation semiconducting materials for transparent and flexible electronics due to their high electrical performance. Moreover, since the oxide semiconductors show high sensitivity to light illumination and possess persistent photoconductivity (PPC), these properties can be utilized in realizing optical memory devices, which can transport information much faster than the electrons. In previous works, metal-oxide semiconductors are utilized as a memory device by using the light (i.e. illumination does the "writing", no-gate bias recovery the "reading" operations) [1]. The key issues for realizing the optical memory devices is to have high photoconductivity and a long life time of free electrons in the oxide semiconductors. However, mono-layered indium-zinc-oxide (IZO) and mono-layered indium-gallium-zinc-oxide (IGZO) have limited photoconductivity and relaxation time of 570 nA, 122 sec, 190 nA and 53 sec, respectively. Here, we boosted up the photoconductivity and relaxation time using a double-layered IZO/IGZO active layer structure. Solution-processed IZO (top) and IGZO (bottom) layers are prepared on a Si/SiO2 wafer and we utilized the conventional thermal annealing method. To investigate the photoconductivity and relaxation time, we exposed 9 mW/cm2 intensity light for 30 sec and the decaying behaviors were evaluated. It was found that the double-layered IZO/IGZO showed high photoconductivity and relaxation time of 28 uA and 1048 sec.

• Applied Biological Chemistry
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• 제9권
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• pp.59-64
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• 1968

1. 국자(?子)를 사용(使用)하여 백미(白米) 및 옥수수를 원료(原料)로 탁주(濁酒)를 담금하고 경시적(經時的)으로 그 발효(醱酵)술덧중(中)의 Amino-N를 Formol 법(法)으로 정량(定量)하고 또한 유리(遊離) Amino 산(酸)을 PPC 법(法)으로 검출(檢出).하였다. 2. 백미정료탁주(白米定料濁酒)술 덧 중(中)에서는 Aspartic acid, Cystine Glutamic acid, Glycine, Serine Alanine, Tyrosine, Histidine, Valine, Tryptophan, Phenylalanine, Proline 및 Leucine 등 14종의 Amino 산(酸)을 검출(檢出)하였다. 3. 옥수수원료탁주(原料濁酒)술덧 중(中)에서는 Aspartic acid, Cystine, Glycine, Derine, Alanine, Lysine, Valine, Aistididine, Proline, Leucine 및 Tryptophan 등(等) 12종(種의) Amino 산(酸)을 검출하였다. 4. 백미(白米) 및 옥수수원료(原料) 탁주중(濁酒中)의 주체 Amino 산(酸)은 Paper Chromatography에 나타난 각(各) Spot의 정색도(呈色度)로 보아 Lysine, Valine, Leucine, Serine, Proline 및 Glycine 등(等)으로 추정(推定)하였다.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1998년도 PROCEEDINGS OF THE 14TH KACG TECHNICAL MEETING AND THE 5TH KOREA-JAPAN EMGS (ELECTRONIC MATERIALS GROWTH SYMPOSIUM)
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• pp.39-43
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• 1998

Single crystals of{{{{ { Zn}_{ 1-x} {Mn }_{x }{Te} }}}} with x=0.3-0.6 were prepared by the standard Bridgeman method. Diffuse neutron diffraction intensities due to the short range magnetic ordering is found in the vicinities of 1 1/2 0 reciprocal point and its equivalent point, indicating that the magnetic correlation of the clusters is the type III antiferromangetic one do the F-type Bravais class crystals, being identical with that of {{{{{ Cd}_{ 1-x} {Mn }_{x }Te }}}}. Neutron inelastic scattering measure-ment has been performed for {{{{{ Zn}_{ 0.6} { Mn}_{ 0.4}Te }}}} sample using the cold neutron spectrometer. AGNES. High resolution measurement with the energy resolution of {{{{ TRIANGLE E= +- .01meV}}}} was carried out in the temperature range from 10K to the ambient. Critical scattering, closely related with the spin glass transition, has been observed for the first time in this semimagnetic semi-conductor. The critical scattering is observed at temperatures in the vicinity of the spin glass transition temperature, 17K. The scattering is observed as a kind of quasielastic scattering in the reciprocal range where the elastic magnetic diffuse scattering has been observed, e.g., 11/20 reciprocal point, indicating the spin fluctuation has dynamic components in this material. Photoconductivity has been discovered below 150K in {{{{{ Zn}_{ 0.4} {Mn }_{0.6 } Te}}}}. The electric AC conductivity has been increased dramatically under the laser light with the wave lengths of {{{{ lambda =6328,5145 and4880 }}}}$\AA$ ,respectively. After the light was darkened, the conductivity was reduced to the original level after about 2000 seconds at 50K, being above the spin glass transition temperature. This phenomenon is the typical persistent photoconductivity; PPC which was similarly found in {{{{ { Zn}_{ 1-x} { Mn}_{x} Te}}}}.

• 펄프종이기술
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• 제37권2호
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• pp.38-46
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• 2005

Experimental work was carried out in order to produce a novel grade of ink-jet paper that has both high print-out quality and price competitiveness. Usually, silica and PVOH has been used for ink-jet paper to design the coating layer that has a hydrophilic and micro-porous structure. However, poor rheological characteristics and low productivity of the silica-PVOH system make the price of the ink-jet paper high. The main focus of this study was replacing the conventional silica (coating pigment) PVOH (binder) coating system with the new PCC (coating pigment) cationic starch (binder) coating system, and optimizing thecoating technology associated with PPC-cationic starch system. In this study, ink-jet print quality of PCC-coated papers was compared with that of silica-coated paper. Two types of PCC were used: conventional type and colloid type. It turned out that PCC C, a conventional coating pigment, has not given a desirable result: it showed high dot reproduction, but it gave low optical density. In spite of low dot reproduction, the qualities of PCC A were comparable or superior to those of silica in optical density, color reproduction, and the uniformity of printing surface. It was also shown that the problems that are happened when the dosage level of cationic starch was too low were varied with ink-type used in each printer. However, in the case of low binder level, the produced image was widely spread resulting fromtoo low optical density of images, or from the lack of bonding ability to set ink into coating surface.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.252-255
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• 2008

건설공사 관리의 목표는 계획된 품질을 적정 비용과 공기로 완성하기 위한 것이며, 이러한 건설공사의 목표를 실현하기 위해서는 효과적인 공정관리가 필요하다. 그러나 현재의 공정관리 방식은 마일스톤에 의한 결과위주의 관리방식으로 작업간의 상호연관성과 변이발생을 충분히 고려하지 못하는 등 여러 한계점이 있다. 이와 같은 공정관리 방식의 한계점을 극복하기 위해 재고 최소화, 낭비 최소화, 관리 능률 향상, 변이 관리 능력 향상 등의 효과를 나타낼 수 있는 린 건설 도입을 제안하고 있다. 따라서 본 연구에서는 린 건설 관리 기법 중 하나인 라스트 플래너 시스템에 관한 연구를 진행하였으며, 특히 라스트 플래너 시스템에서 핵심 단계인 주단위 예상작업계획에서 이루어지는 작업제반요건 분석에 관한 연구를 진행하였다. 그 결과 공정 계획 수립 시 사전에 건설공사의 저해요소를 제어하여 작업의 신뢰도 향상 및 작업계획 달성률을 높일 수 있는 작업제반요건을 식별 및 분류하여 중요도 분석을 실시하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제40권10호
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• pp.888-893
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• 2016

In this study, the solution plasma process was utilized with the aim of degrading synthetic dyes in water at atmospheric pressure. The experiments were conducted in a batch-type reactor consisting of a symmetric wire-wire electrode configuration with rhodamine B (RhB) as the target synthetic dye. The effects of the plasma treatment time and initial dye concentration on the RhB degradation were investigated by monitoring the change in absorbance of RhB solutions. The RhB solutions turned lighter in color and finally colorless with prolonged plasma treatment time, indicating the destruction of dye molecules. The RhB solutions were found to have degraded, following the first-order kinetic process. However, for high initial RhB concentrations, another kinetic process or factor seems to play a dominant role at the initial degradation stage. The fitted first-order rate constant decreased as the initial concentration increased. This result suggests that the degradation behavior and kinetic process of the RhB solution strongly depends on its initial concentration. The RhB degradation is considered to be due to a combination of factors, including the formation of chemically oxidative species, as well as the emission of intense UV radiation and high-energy electrons from the plasma. We believe that the solution plasma process may prove to be an effective and environment-friendly method for the degradation or remediation of synthetic dye in wastewater.

• Journal of Advanced Marine Engineering and Technology
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• 제40권10호
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• pp.894-898
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• 2016

Solution plasma is a unique method which provides a direct discharge in solutions. It is one of the promising techniques for various applications including the synthesis of metallic/non-metallic nanomaterials, decomposition of organic compounds, and the removal of microorganism. In the context of nanomaterial syntheses, solution plasma has been utilized to produce carbon nanoparticles and metallic-carbon nanoparticle systems. The main purpose of this study was to synthesize nickel nanoparticles embedded in a matrix of carbon particles by solution plasma in one-step using waste vegetable oil as the carbon source. The experimental setup was done by simply connecting a bipolar pulsed power generator to nickel electrodes, which were submerged in the waste vegetable oil. Black powders of the nickel nanoparticles-embedded carbon (NiNPs/Carbon) particles were successfully obtained after discharging for 90 min. The morphology of the synthesized NiNPs/Carbon was investigated by a scanning electron microscope, which revealed a good dispersion of NiNPs in the carbon-particle matrix. The X-ray diffraction of NiNPs/Carbon clearly showed the co-existence of crystalline Ni nanostructures and amorphous carbon. The crystallite size of NiNPs (through the Ni (111) diffraction plane), as calculated by the Scherrer equation was found to be 64 nm. In addition, the catalytic activity of NiNPs/Carbon was evaluated by cyclic voltammetry in an acid solution. It was found that NiNPs/Carbon did not show a significant catalytic activity in the acid solution. Although this work might not be helpful in enhancing the activity of the fuel cell catalysts, it is expected to find application in other processes such as the CO conversion (by oxidation) and cyclization of organic compounds.

• 한국건설관리학회논문집
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• 제7권4호
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• pp.146-153
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• 2006

라스트 플래너는 린 건설의 핵심적인 생산관리 이론으로 공정간 신뢰도를 향상시키는 것에 목적을 두고 있다. 해외의 여러 연구기관 및 기업체들이 린 건설의 이론 및 라스트 플래너 방법을 사용하여 많은 사례연구를 수행하였다. 최근 국내의 건설 업체 및 연구기관에서 린 건설 및 라스트 플래너 방법이 소개되었고, 이에 대한 연구 및 도입에 많은 노력을 기울이고 있다. 그러나 국내 건설업체가 라스트 플래너를 공정관리 방법으로 도입함에 있어 기존의 공정관리 방법과의 상이성, 조직 구성의 차이, 문화적 차이 등으로 인한 많은 어려움에 직면하고 있다. 또한, 공사시공의 상당부분을 협력업체의 외주에 의존하는 현실에서 협력업체가 라스트 플래너 공정관리의 주체로 참여하지 않고는 효과적인 라스트 플래너를 수행하는데 있어 어려움이 있다. 본 연구는 국내의 건설업체의 토목공사 현장을 대상으로 라스트 플래너 방법을 수행하였다. 본 연구에서는 3개월간 라스트 플래너 방법 수행하면서 획득한 결과를 토대로 수행연구 분석하였고, 라스트 플래너 방법을 수행하는데 있어 영향을 미칠 수 있는 생산외적 요소들에 대하여 서술하였다.