• Title/Summary/Keyword: Opening rate

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Cooling Characteristics of Fruits and Vegetables for Pressure Cooling (차압통풍 예냉 청과물의 냉각특성)

  • 윤홍선;박경규
    • Food Science and Preservation
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    • v.4 no.3
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    • pp.237-243
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    • 1997
  • Numerous variables affect product cooling rate of pressure cooling system for fruits and vegetables. These include carton vent area, initial and desired final product temperature, flow rate and temperature of the cooling air, product size, shape and thermal properties and product configuration(whether in bulk or packed in shipping cartons). This study was carried out to determine the influence of each of these variables as they affect cooling time. The opening ratio and number of the vent hole were recomended as 4∼10% and 2∼4ea., respectively, for a minimum alt flow resistance and for a uniform air flow pattern. In the cooling experiment for tomatoes and mandarins, optimum air flow rate was 0.04 m3/min.kg in terms of energy saving. The cooling air temperature should be about 2$^{\circ}C$ less than the desired final product temperature for reducing cooling time.

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Considerations of the Small-Crack Growth Law Based on COD (CRACK 개구변위(開口變位)에 기초한 미소피로(微小疲勞)크랙 전파법칙(法則)의 고찰(考察))

  • Kim, Min-Gun;Ji, Jueng-Keun
    • Journal of Industrial Technology
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    • v.13
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    • pp.49-57
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    • 1993
  • Bending fatigue tests were carried out on the specimenes with two different strength levels in order to investigate small crack growth rate. The main results obtained are as follows : (1) Small crack growth law, $da/dn=C{\sigma}_a{^n}a$ is useful several materials, but is not the rule applicable to all cases generally. (2) When da/dn in several specimens are equal, COD near the crack tip are also nearly equal. (3) Crack tip opening displacement(CTOD) is the main factor to control the small crack growth rate, and da/dn ${\propto}$ CTOD comes into being between the two. Accordingly, $da/dn=C({\sigma}_a{^2}/{\sigma}_s){^n}a^n$ shows the small crack growth rate being reflected crack closure phenomenon.

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The Comparison for International competitiveness of Domestic Banks' Foreign exchange commissions (국내은행 외환수수료의 국제경쟁력 비교)

  • Ahn, Yeung-Tae
    • International Commerce and Information Review
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    • v.10 no.1
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    • pp.315-327
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    • 2008
  • According to the Bank Profitabilities Statistics of OECD members, Our domestic banks applying commissions for both exchange and selling/buying foreign currencies are evaluated as much higher than those of other countries banks. The theory indicates an analysis results and comparison in between banks over the world. Our domestic bank assert that, in general, the aggregated banking commission income is lower than those of other countries by comparing in the field of non-interests profits. Viewing by another analysis in details, some commission rate applying to domestic services are far below than cost basis, but other commission rate applying to foreign currency transaction services is abnormally higher. Such unfair rate should be lowered to the similar level to other banks in the world and also the actual cost should be reasonably reevaluated in the reasonable manner. One more thing, The writer suggest that domestic banks should spend efforts to increase their income by improving and diversifying with the various type of new commissions applied to domestic market, such as multi-functional financial services, expanding ATM services, electronic settling technique etc under today's rapidly changing and opening world financial market.

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Analysis of Transient Characteristics of a Steam Power Plant System (증기발전 시스템의 과도상태 특성 해석)

  • Park, Keun-Han;Kim, Tong-Seop;Ro, Sung-Tack
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.7
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    • pp.967-975
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    • 2000
  • Transient characteristics of a boiler and turbine system for a steam power plant are simulated. One-dimensional unsteady models are introduced for each component. An interaction between boiler and turbine and a control of the water level in the drum are taken into account. Transient responses of the system to the variations of main system variables such as fuel and air flow rate, cooling water injection rate at the attemperator, gas recirculation rate at the furnace and opening of the turbine control valve are examined. Effect of fluid inertia and tube wall thermal inertia on predicted dynamic behavior is investigated.

Characteristics of Laryngeal-Diadochokinesis (L-DDK) in Nonfluent Speakers (비유창성 화자의 후두 교호운동 특성)

  • Han, Ji-Yeon;Lee, Ok-Bun;Park, Hee-Jun;Lim, Hye-Jin
    • Speech Sciences
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    • v.14 no.2
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    • pp.55-64
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    • 2007
  • Laryngeal DDK involve with the rate, pattern, and regularity (periodicity) in opening and closing of vocal fold. This study was aimed at investigating the characteristics of laryngeal DDK between nonfluent and fluent speakers. One with an ataxic dysarthria (with cerebellar lesion) and the other with stuttering, and 13 normal speakers were evaluated. L-DDK were analyzed with MSP (motor speech profile, CSL 4400). Measures of DDK included: DDKavr, DDKcvp, DDKjit, DDKavp. An ataxic dysarthric speaker and a stutterer showed more reduced rate and aperiodic L-DDK (both adductory and abductory movement) than normal speakers. But the average L-DDK period (ms) in adductory movement in a speaker with stuttering showed more decreased than the other. Results from this study are preliminary. Nonetheless, results of L-DDK produced by nonfluent speakers suggested the possibility to have relation with slow rate of phonatory initiation and connected speech. In the future, perceptual studies are needed in conjuction with acoustic and speech production.

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Fatigue Growth Behavior of Short Cracks (짧은균열의 피로성장거동)

  • 최용식;홍성호;우흥식;한지원
    • Journal of the Korean Society of Safety
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    • v.8 no.1
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    • pp.54-58
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    • 1993
  • The fatigue growth behavior of short cracks were studied various load ratios. Computer-aided unloading elastic compliance method was employed to measure the closure and the length of short cracks. In the dc/dN-$\Delta$K relationships. the decreasing behavior of the growth rate of short cracks is due to the decrease of crack opening ratio with increasing crack length. Irrespective of load ratio. the growth rate of short cracks can be well decribed in terms of the effective stress intensity factor range $\Delta$K$_{eff}$, which is calculated on the base of crack closure. dc/dN-$\Delta$K$_{eff}$ relationships of short cracks are found to coincide well with the corresponding long crack relationships. accordingly. the growth rate of short cracks can be predicted using that of long cracks.ort cracks can be predicted using that of long cracks.cks.

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Effect of the U.S. Monetary Policy on the Real Economy of the Asia: Focusing on the impact of the exchange rate in Korea, China and Japan (미국의 통화정책이 아시아 실물경제에 미치는 영향: 한국, 중국, 일본의 환율충격을 중심으로)

  • Choi, Nam-Jin
    • International Area Studies Review
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    • v.20 no.2
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    • pp.3-23
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    • 2016
  • In this study, we used actual proof analysis, based on SVAR model according to economy theory, to observe the impact of actual and financial market of Korea, Japan, and China that have adopted quantitative easing export based strategy of growth, an unconventional monetary policy of the U.S. As a result of estimation, it appears that real effective exchange rate rise shock of Korea, Japan, and China against U.S. dollar has a negative influence on current account and index of industrial product, which are real economy. It can be implied that the result is driven from the fact that strong home currency of Korea, Japan, and China decreases price competitiveness of exports, causing negative influence on real economy. The real effective exchange rate shock against U.S. dollar appeared to decrease national bond rate of Korea and Japan, while increasing that of China. In instances of Korea and Japan, it is implied that national bond rate decreases as foreigner investment funds flow in, considering foreign-exchange profit through advanced financial market with high opening extent. On the other hand, because there are strong regulation on opening extent of Chinese financial markets, the influence seems to be greater for domestic policy, rather than a foreign influence. Lastly, Korea showed a more dramatic variable reaction to exchange rate shock compared to Japan or China. It is implied from the result that Korea is relatively more susceptible and fragile in regards of international status of economic size and currency.

The Building Energy Efficiency Rating Evaluation of Apartment depending on SC and Window area ratio (차폐계수와 창면적비에 따른 공동주택의 건물에너지효율등급 평가)

  • Jang, Cheol-Yong;Han, Hye-Sim;Lee, Jin-Sook
    • Journal of the Korean Solar Energy Society
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    • v.30 no.5
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    • pp.38-43
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    • 2010
  • Enhancement of exterior's insulation performance like wall or window etc. is general way for building's energy efficient and thermal performance. But exterior's opening plan is important for minimizing the energy consumption and heat loss. In this paper, energy saving rate will be analyzed and compared considering the window area's rate and window's SC(Shading Coefficient) in a apartment with Building Energy Efficiency Rating System's evaluation tool. In the process of evaluation, energy saving rate is measured at each stage of the window area's rate from 20% to 60% every 10% term and the shading coefficient value from 1.0 to 0.6. As a result of this research, energy saving evaluation could not be measured exactly with existing evaluation tool. Accord this research, Building Energy Rating System's evaluation range is needed to be broaden for exact evaluation of energy saving rate.

A Model Experiment on the Basic Efficiency of Midwater Rope Trawl Net (로프 트롤 그물의 기본성능에 관한 모형실험)

  • Yae, Young-Hee;Lee, Byong-Gee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.29 no.3
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    • pp.200-213
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    • 1993
  • A model experiment on a midwater rope trawl net which is used in the North Pacific to catch alaska pollack is carried out in the circulating tank to examine the basic efficiency of the net. The prototype is the net used by M/S Hanil(1, 179GT, 2, 700PS), a Korean trawler. The model net was made according to the Tauti's Similarity Law of Fishing Gear in 1/100 scale by considering the condition of the tank. To measure the basic efficiency of the standard model net, the vertical opening and width between some points marked on the net were measured, and the hydrodynamic resistance were determined. Then the constructive conditions of the net were varied as follows and the factors were measured again to compare the efficiency of those nets with that of the standard net(A-1 type) front weight multiplied 1.5 times: A-2 type. buoyancy and depressing force multiplied 1.7 times: A-3 type. front weight multiplied 1.5 times on A-3 type: A-4 type. depressors rigged at ground rope: B type. cod-end stuffed with cashmylon wad: C type. The results obtained can be summarized as follows: 1. The vertical opening at the center of head rope was steeply decreased with the flow velocity increasing and the vertical opening H(m) can be expressed in H=1.2v super(-1.2)(v : flow velocity in m/sec). The width of the net varied a little when the flow velocity was over 0.4m/sec, and the width of net mouth showed about 37% of the distance between the fore tips of net pendant. The shape of net mouth was almost a circle at 0.2m/sec and then steeply flatted elliptically with the flow velocity increasing and the area of mouth S(m super(2)) can be expressed in S=(1.65-2.3v)$\times$10 super(-2). The hydrodynamic resistance of the net increased almost linearly with the flow velocity increasing and the resistance R(kg) can be expressed in R=3.2$\times$d/l$\times$abv. where d/l denotes the mean of d(diameter of netting twine) and l(length of a leg in a mesh) from wing tip to the end of bag-net except cod-end on the side pannel, and a denotes the strectched circumference of the net at the fore end of a meshed part and b the stretched length of the whole net from wing tip to the end of cod-end. 2. In the condition-varied nets, the vertical opening of head rope showed some increase in every type net except the C type, and the increase showed the greatest in the B type by 30~54%, whereas it showed decrease in the C type by 5~10%. Variation of the area of net mouth showed almost the same tendency as the vertical opening and the increase showed the greatest in the B type by 20%, whereas it showed decrease in the C type by 12%. Hydrodynamic resistance showed some increase in every type compared with the standard net, and the rate of increase indicated 5~10% in the A-2, A-3 and A-4 type, 22% in the B type and 3% in the C type.

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Experimental Study on Wind-driven Ventilation in Basement Parking Lots of Apartment (풍동실험을 통한 공동주택 지하주차장의 자연환기 성능 연구)

  • Lee, Si-Woong;Roh, Ji-Woong
    • KIEAE Journal
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    • v.4 no.3
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    • pp.103-107
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    • 2004
  • This paper aims for evaluating the wind-driven ventilation in basement parking lots of apartment. Wind tunnel tests coupled with tracer gas method were conducted, and classified by wind directions and opening types. The test results showed that, as for wind-driven ventilations, stack type openings were more successful than scuttle vent. Finally, according to Weibull distribution in Seoul, yearly averaged wind-driven ventilation rate was calculated.