• 제목/요약/키워드: pre-cut

검색결과 226건 처리시간 0.048초

The Circular Center Cut with Large Empty Hole & Pre-Splitting in Tunnel Blasting (터널에서 대구경 무장약공과 선균열을 이용한 심빼기 공법에 관한 연구)

  • 김재홍;임한욱
    • Tunnel and Underground Space
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    • 제11권3호
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    • pp.248-256
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    • 2001
  • The cylindrical cut is most frequently used in tunnel blast regardless of their dimensions. In this study the new parallel cut is proposed to raise advance per round, which is considered to be an elevation of the traditional cylinder cuts. The general geometric pattern of a new cut with parallel blast holes is proposed. The detailed burden and spacing between the central blasthole and those of the four section are also given. The blast results between new cut and traditional cylinder cut are given. The main results of this study are as follows. 1) The average advances per rounds in new cuts can reach 99.5% of drilling length. That of traditional cylinder cuts are known approximately 90∼95% 2) Specific charge weight of new cut compare to that of cylinder cut is approximately reduced 5% from 1.363 to 1.297 kg/㎥ 3) Specific drilling rate is also reduced 8% from 2.393 to 2.130 m/㎥ 4) Vibrations, fly rock, and fragmentation produced by the new blast are to be proved superior to those of the traditional cylinder cuts.

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The Intake and Palatability of Four Different Types of Napier Grass (Pennisetum purpureum) Silage Fed to Sheep

  • Manyawu, G.J.;Sibanda, S.;Chakoma, I.C.;Mutisi, C.;Ndiweni, P.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권6호
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    • pp.823-829
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    • 2003
  • Four different types of silage from new cultivars of Napier grass (Pennisetum purpureum), cv. NG 1 and NG 2, were fed to eight wethers in order to evaluate their preference and intake by sheep. The silages were prepared from direct-cut NG 1 herbage; pre-wilted NG 1 herbage; NG 1 herbage with maize meal (5% inclusion) and NG 2 herbage with maize meal (5% inclusion). All silages were palatable to sheep. Maize-treated silage had high quality fermentation, characterized by high Fleig scores and low pH, volatile fatty acids (VFA) and ammoniacal nitrogen contents. The pH, Fleig score, in vitro digestible organic matter (IVDOMD) and ammoniacal-N contents for maize-treated cv. NG 1 silage were 3.7, 78, $540g\;kg^{-1}$ dry matter (DM ) and $0.18g\;kg^{-1}$ DM whereas, in maize-treated cv. NG 2 they were 3.6, 59, $^458g\;kg{-1}$ DM and $0.18g\;kg^-1$ DM, respectively. The superior quality of maize-treated silages made them more preferable to sheep. Among the maize-fortified silages, palatability and intake were significantly (p<0.001) greater with cv. NG 1. Although direct-cut silage had better fermentation quality compared to wilted silage, wilted silage was significantly (p<0.001) more preferable to sheep. However, there were no significant differences (p<0.05) in the levels of preference and intake of wilted silage compared to maize-treated cv. NG 2 silage, even though the latter tended to be more palatable. There were indications that high pH (4.6 vs 3.5) and IVDOMD content (476 vs $457g\;kg^{-1}%$ DM) of wilted silage contributed to higher intake, compared to direct-cut silage. It was generally concluded that pre-wilting and treatment of Napier grass with maize meal at ensiling enhances intake and palatability.

Effect of Consulting on Microcredit Repayment in Korea

  • OH, YOONHAE
    • KDI Journal of Economic Policy
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    • 제37권3호
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    • pp.55-74
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    • 2015
  • This study examines the effect of a one-on-one outsourced pre-lending consulting service on the repayment behavior of microcredit borrowers in Korea with administrative data from the Smile Microcredit Bank. A random change in the cut-off loan amount for mandatory consulting is utilized as an identification strategy. This three-day pre-lending business consulting service is effective in encouraging repayment behavior of existing businesses but it has no significant effect on start-up loans. The effectiveness of the consulting service in deterring delinquency with regard to existing loans is greater among male borrowers than among females.

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Design of A Biased Random Vector Generator for A Functional Verification of Microprocessor (마이크로프로세서 기능 검증을 위한 바이어스 랜덤 벡터 생성기 설계)

  • 권오현;양훈모;이문기
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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    • pp.273-276
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    • 2002
  • In this paper, we propose a bias random vector generator which can verify functions of microprocessor effectively. This generator is a pre-processor of assembly program, and defines pre-processor instructions which create random vector only in the pall which the designer wants to verify. Therefore, this generator shows higher detection ration than any other generators. And, we can cut down design costs because of shortening a Period for verifying function.

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Design of A Biased Random Vector Generator for A Functional Verification of Microprocessor (마이크로프로세서 기능 검증을 위한 바이어스 랜덤 벡터 생성기 설계)

  • 권오현;양훈모;이문기
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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    • pp.121-124
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    • 2002
  • In this paper, we propose a bias random vector generator which can verify functions of microprocessor effectively. This generator is a pre-processor of assembly program, and defines pre-processor instructions which create random vector only in the part which the designer wants to verify. Therefore, this generator shows higher detection ration than any other generators. And, we can cut down design costs because of shortening a period for verifying function.

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Observation for Machinability of Hardening Particle Dispersed Iron Based Sintered Alloy

  • Tamori, Ryo;Ishihara, Naoshi
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.301-302
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    • 2006
  • Machinability and machining mechanism were examined in the case where resin impregnation treatment was conducted to the Mo-Co hardening particle dispersed iron-based sintered alloy. As a result, the force required for machining decreased significantly compared with the case where resin impregnation treatment was not conducted. This effect is considered to be attributable to the embrittlement of cutting chips produced by the minimization of the cut material deformation.

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Study on Acceleration of Building a Thesaurus by Means of Pre-applying of $\alpha$-cut ($\alpha$-cut 선적용에 의한 시소러스 구축의 가속화에 관한 연구)

  • 김창민;김용기
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 한국퍼지및지능시스템학회 1997년도 추계학술대회 학술발표 논문집
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    • pp.233-236
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    • 1997
  • 퍼지 관계 개념을 응용한 퍼지 정보 검색은 형태론에 입각한 기존의 정보 검색과는 달리 문서와 용어의 의미론에 근거하는 정보검색을 할 수 있다. 퍼지 정보 검색은 문헌의 집합 용어의 집합으로 나누고 문헌과 용어의 관계성을 문서 $\times$ 용어이 관계 행렬로 나타내며 퍼지 관계곱 연산을 이용하여 시소러스(thesaurus)를 형성하고 사용자로부터 주어진 질의 적합한 문서를 제공한다. 그러나 이러한 퍼지 관계곱 연산은 매우 큰 시간 복합도를 요구하는 연산이고 퍼지값은 부동소수점으로 표현해야하므로 대용량의 문서 시스템에 적용할 수 없어 비현실적이다. 부동소수점 연산은 연산속도가 느리고 저장공간도 많이 요구하므로 부동소수점 연산을 비트 연산으로 대체할 수 있다면 처리속도와 처리공간에 있어 성능 향상을 기대할 수 있다. 본 연구는 퍼지 정보 검색의 시소러스 형성에 있어 $\alpha$-cut 적용의 시기를 조정하여 성능을 향상하는 방법을 제안한다.

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Influence of SAC Shape on Injection Characteristics and Spray (SAC 형상이 분사특성 및 분무형상에 미치는 영향)

  • 김상진;권순익
    • Transactions of the Korean Society of Automotive Engineers
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    • 제9권2호
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    • pp.11-18
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    • 2001
  • To clarify the influence of SAC shape of hole-type diesel nozzle on injection characteristics and spray patterns, the injection rate of three nozzle types(standard SAC nozzle, Needle-cut VCO nozzle and VCO nozzle) were measured by Zeuch's method and pictures of the sprays were taken by CCD camera. As the pump speed became higher, the injection characteristics of the three nozzles were different. Injection rate and perssure curves at the high pressure pipe in Needle-cut VCO nozzle were much more similar to the VCO nozzle than those of the SAC nozzle. When the needle was at pre-lift period for all speeds, the spray of the Needle-cut VCO nozzle showed almost the same shape as the SAC type nozzle. There was no differense in spray pattern at the needle full-lift periods.

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The Iconography of Femininity in Pre-Raphaelite Painting

  • Choe, Jian
    • English & American cultural studies
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    • 제14권1호
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    • pp.269-286
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    • 2014
  • The Pre-Raphaelite oeuvre abounds in the image of women, which indicates the impact of gender question on contemporary visual culture. The representation of women in their art tends to evince the entrenched myth of womanhood, marked by a stereotyped dichotomy in the apprehension of femininity. Yet there are a significant number of pictures which attest to the point that their iconography of womanhood cannot be fully elucidated by exploring the dichotomy alone. They falsify the dyadic model, defying the attempt to accommodate them in a clean-cut category. The curious blend of the mystical, the sensual, and the domestic that characterizes these images suggests that they are open to multiple interpretations. In sum, the Pre-Raphaelite representation of women both endorses and challenges the ideal of femininity, indicating that it was shaped by and shaped contemporary perceptions of women at a time when gender relations were shifting and the traditional institution of patriarchy revealed a sign of strain.

Effect of Pre-wilting on the Forage Quality of Organic Sorghum$\times$Sudangrass Silage (예건이 수수$\times$수단그라스 교잡종 유기 사일리지의 품질에 미치는 영향)

  • Lim, Hyun-Jin;Kim, Jong-Duk;Lee, Hyun-Jin;Jeon, Kyeong-Hup;Yang, Ka-Young;Kwon, Chan-Ho;Yoon, Sei-Hyung
    • Korean Journal of Organic Agriculture
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    • 제17권4호
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    • pp.519-527
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    • 2009
  • The main nutritional problem of sorghum$\times$sudangrass hybrid silage is low quality and dry matter (DM) contents. This experiment was conducted to evaluate whether field pre-wilting treatment of sorghum$\times$sudangrass hybrid silage increases DM content and forage quality of the silage. The experiment was a randomized complete block design with three replications. The treatments were consisted of five different wilting days: 0 day (direct cut silage), 0.5 day, 1 day, 2 days and 3 days. Sorghum$\times$sudangrass hybrid silage with pre-wilting showed low 4.00 pH values, however direct cut silage (control) showed a 4.30 value because of its high moisture content. The DM content of sorghum$\times$sudangrass hybrid silage with pre-wilting was high above 25.1% after 1 days, however that of direct cut silage had 17.6%. And the effluent of wilted silage was decreased with prolonged wilting period, but that of direct cut silage produced effluent of 183 mL/kg. Crude protein and ether extract with wilted silage were decreased, however crude ash was increased with prolonged wilting period. Silage with pre-wilting had higher acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents than control silages, while its non-fiber carbohydrate (NFC) showed the opposite results. Lactic acid and total organic acid were increased with prolonged wilting period. For the palatability of dairy goat, silage with 2 days wilting was highest among silages. The experiment results indicate that wilted sorghum$\times$sudangrass hybrid silage could be recommended as effective method for reducing effluent, increasing pH and forage quality more than direct cut silage. Optimum pre-wilting day of sorghum$\times$sudangrass hybrid silage may be 1 days.

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