• Title/Summary/Keyword: Cut-on condition

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A Study on the Spatial Composition influenced by climatic conditions in 19C Bahay na Bato around Cebu city in Philippines (19C 필리핀 세부(Cebu) 바하이 나 바토(bahay na bato) 주택의 기후적 인자를 고려한 공간 구성에 관한 연구)

  • Kim, Young Hoon;Lim, Sooyoung
    • KIEAE Journal
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    • v.13 no.6
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    • pp.29-37
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    • 2013
  • The modern town houses in Philippines has been changed through Spanish colonization over 300years and American military administration in 20C. Especially Cebu, the first contemporary capital of colonized Philippines by Spain, has various cultural characteristics and historical remains including old houses. By the economy condition in Cebu growing up, Bahay na bato, stone and wood house, has been settled for the elite or middle class of Cebu around 19C influenced by Spanish or Europe and Philippines native house called bahay kubo. Bahay na bato shows a common features, as revealed in this study, which all of them has a two stories with cut stone curtain wall and wooden beam and lintel, fronting the main street by approaching directly from street. And spatial separating also shown by setting living space to upper level instead of using storage or entrance hall called zaguan in lower level. Bahay na bato studied here shows a particular appearances in elevation, having volada and elaborate geometric or floral window pattern, also playing a role for ventilation with vetanilas below volada and main window in section. They have a rectangular plan with caida, sala, comedo, azotea almost similar to Spanish and ealier colonial Mexico style mixed with Philippines traditional style showing the strong spatial separation functionally and space wideness for party occasionally.

A Study on the Development of Large Aluminum Flange using Casting/Forging Process (주조/단조 기술을 이용한 대형 알루미늄 플랜지 개발에 관한 연구)

  • 배원병;왕신일;서명규;조종래
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.905-909
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    • 2001
  • The significance of casting/forging process for reducing the production cost of large components is being noted in these days. This casting/forging process is a method of forging a workpiece preformed by casting into the final shape. In this study, the casting/forging process has been applied in manufacturing a large aluminum flange in order to determine the optimum forging condition of the aluminum flange. The optimum range of forging temperature of Al 5083 was from $420^{\circ}C$ to $450^{\circ}C$. The suitable strain rate was 1.5 $sec^{-1}$. The deformation amount of a preform in a forging process is key role in the mechanical properties of casting/forging products. In order to find the change of mechanical properties according to effective stain of cast aluminum billets, a hot upsetting test were performed with rectangular blocks and then a uniaxial tensile test was performed with specimens cut from the upsetted billets. The tensile strength and the elongation of cast/upsetted aluminum billets were increased largely until the effective strain was 0.7. FE analysis was performed to determine the configurations of cast preform and die for an aluminum flange. In the FE analysis, the forging load-limit was fixed 1500ton for the low equipment cost. The cast preform was designed so that the effective stain around the neck of a flange exceeds 0.7. In the forging experiment for an aluminum flange, it was confirmed that the optimal configuration of the cast preform predicted by FE analysis was very useful. The cast/forged products using designed preform were made perfectly without any defects.

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Analysis and Proposals Concerning Big Deals of Scholarly Journals (학술지 빅딜판매의 문제점 및 개선 방안)

  • Shin, Eun-Ja
    • Journal of the Korean Society for Library and Information Science
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    • v.41 no.1
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    • pp.373-389
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    • 2007
  • The most remarkable business model to Have merged in electronic publishing is the so-called 'Big Deal'. Major Publishers have begun offering libraries bundled packages that are across journals and across print and electronic versions. This paper examined consortium conditions of scholarly journals in the light of big deal. The result skewed that various pricing models have been appeared and freedoms to choose collections have been on the increase in comparison with the past. But many major Publishers have adopted a typical big deal contract condition that a library enters into a long-term arrangement to get access to large electronic journal collections at a dramatic discount interchange of a promise not to cut print subscriptions. The publishing and library communities need to find alternative pricing models that provide better deals for those disadvantaged by the prevalence of the big deal. Much in the world of scholarly publication is changing, combination of traditional publishing and open access publishing may well be gained public favor in the future.

Fresh Produce Container Operated with a Routine of Hypobaric Application, CO2 Injection and Diffusion Tube Opening for Keeping Beneficial Modified Atmosphere

  • Park, Su Yeon;An, Duck Soon;Lee, Dong Sun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.26 no.2
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    • pp.53-60
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    • 2020
  • A concept of household container to create and keep the modified atmosphere (MA) beneficial for fresh produce mix was devised and tested under typical chilled storage conditions of 3℃. The container system containing mixed products is initialized by applying weak hypobaric condition (0.9 atm) and subsequently injecting CO2 gas at an appropriate low level (0.03 atm). The passive atmosphere modification by produce respiration is then induced to reach a target until gas diffusion tube of proper dimension starts to open. The design was made to attain quasi-steady state mass balance of O2, CO2 and N2 to maintain the desired MA through the storage. Interrupted opening for taking out or placing some products was to reinitialize the loop of control logic. The developed concept was tested by the container which held commodities of spinach, pak choi, oyster mushroom, peeled onion, strawberry and cut carrot. The target optimum MA of 11% O2 and 10% CO2 (0.11 and 0.10 atm, respectively) was set to avoid injurious range of O2 and CO2 concentrations for any commodities. The developed container system could work to reach and maintain beneficial MA of 0.10-0.12 atm O2 and 0.07-0.10 atm CO2 close to the target during the storage contributing to quality retention of products measured in weight loss, chlorophyll content of spinach, ascorbic acid content of pak choi, color of onion, texture of oyster mushroom, bacterial count of strawberry and carotenoids of carrot. The container system shows potential to improve current preservation practice of fresh produce mix on consumers' level.

Studies on Composites Using Wood and Nonwood Fibers - Effects of Polypropylene Fiber Length and Process Variables - (목질(木質)과 비목질계(非木質系) 섬유(纖維)를 활용한 복합재(複合材) 연구(硏究) - 폴리프로필렌의 섬유장(纖維長)과 공정변수(工程變數)의 영향(影響)을 중심(中心)으로 -)

  • Lee, Phil-Woo
    • Journal of the Korean Wood Science and Technology
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    • v.25 no.2
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    • pp.33-44
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    • 1997
  • This study was executed to examine the effects of polypropylene fiber length and process variables of the composites made from wood fiber and nonwood fiber mixed formulations. As a nonwood fiber the polypropylene with 3 denier thickness of tow condition was selected and cut into each length of 0.5, 1.0, 1.5, 2.0 and 2.5cm to mix with wood fiber. And also western hemlock wood fiber for medium density fiberboard was prepared. First, to decide an adequate polypropylene mixing fiber length, the composites of 1.0g/$cm^3$ density were made from 10% polypropylene fiber by each of five lengths and 90% western hemlock fiber mixed formulations. Thereafter as the experiments of process variable, the composites applied with adequate polypropylene fiber length(1.5cm) were made from 4 density levels (0.6, 0.8, 1.0, 1.2g/$cm^3$). 3 mixed formulations of wood fiber to polypropylene fiber(95 : 5, 90 : 10, 85 : 15), and 3 mat moisture contents(5, 10, 20%). According to the results and discussions it was concluded as follows ; The physical and mechanical properties were shown improved tendency. as polypropylene fiber length was increased in the range from 0.5 to 1.5cm, but shown decreasing tendency from 2.0 to 2.5 cm. Accordingly, it was shown that polypropylene fiber length is limited to 1.5cm or less length in mixing wood fiber and polypropylene fiber by turbulent air mixing process. As the densities of wood fiber-polypropylene fiber composites were increased, the physical and mechanical properties were clearly improved. Also they were shown significantly increasement statistically between densities respectively. In the mixed formulations, physical and mechanical properties were shown only slightly improvement, as they changed from 95 : 5 to 85 : 15 in wood fiber to polypropylene fiber. Despite of increasement of mat moisture content, mechanical properties were not improved significantly but physical properties were improved somewhat in wood fiber-polypropylene fiber composites.

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Evaluation of Fly Ash as an Alternative to Clay Liner Material in Landfills (플라이애쉬의 차수 및 오염물 차단 능력 평가 연구)

  • Jeong, Mun-Gyeong;Hyeon, Jae-Hyeok;Kim, Seung-Hyeon
    • Geotechnical Engineering
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    • v.14 no.5
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    • pp.191-204
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    • 1998
  • The feasibility of fly ash was evaluated as an alternative liner material to the conventional clay liner of landfills through modeling and laboratory experiments. In order to consider the effect of unsaturation on water flow through the liner, analyses were made to compare flow characteristics in saturated liner with that of unsaturated one. Contaminant migration characteristics in liners were investigated by batch experiment and modeling, in which phenol was employed as a model was solved by numerical techniques of finite difference method and predictor-corrector method to deal with high non-linearity. Sequential method was used to handle the system of differential equations. Results show that the alternative liner material is more capable of cutting off water flow in unsaturated condition and in preventing phenol from passing through it. It can be seen that, under the flow conditions considered in this study, the conventional saturation approach underestimates the amount of water passing through the liner and doers the cut-off capability against phenol significantly.

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Assessing Distribution of Degree of Saturation for Track Transition Zone Using Soil Water Characteristic Curve (접속부 궤도 성토재료의 함수특성곡선을 이용한 포화도 분포 산정)

  • Choi, Chanyong;Lee, Jungmin;Kwon, Hyeok Min;Oh, Jeongho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.2
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    • pp.515-524
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    • 2015
  • The number of occurrence of differential settlement and track irregularity at track transition zone recently comes to increase, which leads to frequent maintenance activities that have an impact on train operation. Such track transition zone damages are attributed to the change of mechanical properties of fill materials due to environmental factors such as rainfall and freeze, and thaw. Consequently, this study attempts to establish the soil water characteristic curve (SWCC) of fill materials, and conduct seepage analysis to assess the distribution of degree of saturation (DOS) for track transition zone in case of rainfall. The SWCC of fill materials was successfully obtained using filter paper test method. The results of seepage analysis revealed that rainfall intensity, the slope of backfill, backfill condition (fill or cut), and SWCC are significantly influential in controlling the distribution of DOS.

Study on the time-delay compensation of RTK correction message for improvement of continuous position surveying performance under unexpected temporal datalink loss/cut-off (RTK 보정정보 난수신 환경에서의 측위연속성 향상을 위한 시간지연 보상연구)

  • Park, Byung-Woon;Song, June-Sol;Kee, Chang-Don;Yang, Chul-Soo;Tcha, Dek-Kie
    • Journal of Advanced Navigation Technology
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    • v.14 no.5
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    • pp.625-631
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    • 2010
  • In this paper, robustness performance of SNUR message is compared with those of existing ones, RTCM(Radio Technical Commission for Maritime Services) v2 MT(Message Type) 18/19 and MT 20/21 under a poor broadcast condition such as temporary data loss or disconnection We defined the temp oral data loss as 2 second delay and reconnection after disconnection as 7 second latency, and then evaluated its robustness for each latency case by double differentiating the observables. Our result shows that SNUR protocol method can reduce the latency error of the existing RTCM messages by 30~60%. Moreover, a rover using SNUR message, whose latency error is bounded within 1/4 L1 wave length, can figure out its own fixed position continuously in spite of 7 second disconnection, while the other using RTCM message, whose error is larger than half wave length, cannot keep its previous fixed solution.

Storage Quality of Minimally Processed Onions as Affected by Seal-Packaging Methods (포장방법에 따른 신선 편의가공 양파의 저장품질 변화)

  • Hong, Seok-In;Son, Seok-Min;Chung, Myong-Soo;Kim, Dong-Man
    • Korean Journal of Food Science and Technology
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    • v.35 no.6
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    • pp.1110-1116
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    • 2003
  • The effects of packaging methods on the storage quality of minimally processed (prepeeled) onions were investigated to determine the optimal packing design. Various packaging treatments used for modifying headspace atmospheres included two passive MAP using LDPE and PP films, two active MAP using a gas mixture of 20% $O_2/10%\;CO_2/balance\;N_2$ and an ethylene scavenging sachet, and moderate vacuum packaging (MVP). The quality attributes of onion samples were evaluated periodically in terms of flesh weight loss, color of cut surface, decay ratio, microbial counts, and sensory properties during storage at $10^{\circ}C$ for 28 days. Packaging methods did not significantly influence surface color, weight loss, and microbiological populations of mesophiles, psychrotrophs, and lactic acid bacteria. They did, however, affect sensory characteristics as well as decay occurrence. Results indicated that seal-packaging with a gas-permeable plastic film under a mild vacuum condition could retain better onion quality in terms of microbial decay and visual sensory aspects as compared with the other packages.

A Study on the Crack-propagation Mechanism of Pre-splitting Method with Consideration of Stress Field (응력장을 고려한 프리스플리팅 공법의 균열발생 원리에 대한 연구)

  • Yoon, Ji-Sun;Woo, Taek-Gyu;Kim, Min-Woo;Jang, Young-Min
    • Explosives and Blasting
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    • v.27 no.2
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    • pp.1-11
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    • 2009
  • Abstract By investigating the stress redistribution caused by the preceding cut blasting when applying the pre-splitting method to tunnel round, an attempt was made to find conditions that were favorable for the propagation of cracks in contour holes. The investigation of the direction of minor principal stress in the numerical analysis revealed that the most significant factor affecting the change of the direction was the loading condition, while the core shape, rock type, and tunnel depth seemed to be less important in determining the direction of minor principal stress. Moreover, the number of cracks tended to increase with the increase of deviatoric stress. Through the model test of pre-splitting, it is confirmed that the pre-splitting method taking the stress field into account can reduce the extent of yield zone and has advantage in controlling the direction of crack than the conventional one.