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Identifying Wastes in Construction Process and Implementing the Last Planner System in India

  • Bhatla, Ankit;Pradhan, Bulu;Choi, Jin Ouk
    • Journal of Construction Engineering and Project Management
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    • v.6 no.1
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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.

건축실무 전문화에 관한 UIA 국제 표준안

  • Korea Institute of Registered Architects
    • Korean Architects
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    • no.3 s.359
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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

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Boosting up the photoconductivity and relaxation time using a double layered indium-zinc-oxide/indium-gallium-zinc-oxide active layer for optical memory devices

  • Lee, Minkyung;Jaisutti, Rawat;Kim, Yong-Hoon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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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.

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Studies on the Components Korean Sake (Part 2) -Detection of the Free Amino Acids in Takju by Paper Partition Chromatography- (한국(韓國) 주류성분(酒類成分)에 관(關)한 연구(硏究) (제2보(第2報)) -Paper Chromatography에 의(依)한 탁주중(濁酒中)의 유리(遊離) Amino 산(酸)의 검색(檢索)-)

  • Kim, Chan-Jo
    • Applied Biological Chemistry
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    • v.9
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    • pp.59-64
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    • 1968
  • Takju (Korean native Sake) was mashed with two different materials. One of the material was polished rice and Nuruk(mold wheat), the other one was corn and Nuruk. The amino acids in those fermenting mashes were identified by paper partition chromatography at regular intervals. The results were summarized as follows; a) Following 14 kinds of amino acids were identified in the mash of rice material; lysine, valine, proline, leucine, serine, glycine, aspartic acid, alanine, cystine, tyrosine, histidine, glutamic acid, tryptophan and phenylalanine b) Following 12 kinds of amino acids were identified in the mash of corn material; lysine, valine, proline, leucine, serine, glycine, aspartic acid, alanine, cystine, histidine, argrinine and tryptophan. c) The main amino acids in the Takju mash according to the color density of the each amino acid spot on the paper chromatograms were checked as lysine, valine, leucine, serine, proline and glycine.

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Ordering of manganese spins in photoconducting $Zn_{1-x}Mn_xTe$

  • Kajitani, T.;Kamiya, T.;Sato, K.;Shamoto, S.;Ono, Y.;Sato, T.;Oka, Y.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1998.06a
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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}}}}.

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The Effect of Precipitated Calcium Carbonate Having a Small Particle Size on the Print Quality of an Inkjet-Grade Paper (초미립자탄산칼슘이 잉크제트 인쇄품질에 미치는 영향)

  • Lee Yong-Kyu;Lee Hee-Myung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.2 s.110
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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.

Study on Constraints Analysis Classification for PPC Improvement (작업계획달성률 향상을 위한 작업제반요건 분류에 관한 연구)

  • Han, Jung-Hun;Kim, Dea-Young;Lee, Hak-Ki
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.252-255
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    • 2008
  • The purpose of construction project management is to achieve planned quality by adequate cost and schedule of the project, thus the effective time management is a critical factor to actualize the object. But the traditional time management by using milestone has several limitations which are not sufficiently considered mutual relation and variated from the task. On this wise, applying the concept and principles of lean construction to the project will be the best way not only reduce waste and variation, but also improve the productivity and ability to overcome limitation as mentioned above. Thus the study, Last Planner System, specially focuses on constraint analysis which is used in lookahead planning system. The results of this research will provide the constraints classification that is able to improve work reliable and percent plan complete when time planning by controlling constraints of project.

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Degradation of synthetic dye in water by solution plasma process

  • Panomsuwan, Gasidit;Morishita, Tetsunori;Kang, Jun;Rujiravanit, Ratana;Ueno, Tomonaga;Saito, Nagahiro
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.10
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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.

Fabrication of nickel nanoparticles-embedded carbon particles by solution plasma in waste vegetable oil

  • Pansuwan, Gun;Phuksawattanachai, Surayouth;Kerdthip, Kraiphum;Sungworawongpana, Nathas;Nounjeen, Sarun;Anantachaisilp, Suranan;Kang, Jun;Panomsuwan, Gasidit;Ueno, Tomonaga;Saito, Nagahiro;Pootawang, Panuphong
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.10
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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.

Implementing Last Planner : Tunnel Construction Project (라스트 플래너 적용 사례연구 : 터널 프로젝트)

  • Kim, Yong-Woo;Jang, Jin-Woo
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.4 s.32
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    • pp.146-153
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    • 2006
  • The Last Planner(LP), of which the goal is to improve work-flow reliability, has recently been introduced in Korea. It is found that some contractors have made efforts on applying the Last Planner to their projects. However, they face difficulties for a variety of reasons. This paper presents the case study results on Korean heavy civil projects, along with descriptions of the ways that the Last Planner was applied, and how the work flow reliability was improved. It also discusses the prerequisites and barriers to implementation of the Last Planner in applying heavy civil construction projects in Korea. The results can be used as a reference for companies to improve their work flow reliability for future projects.