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The Evaluation of Pollutant Removal Efficiencies by Sedimentation Basin Types constructed at the Inlets of Irrigation Reservoirs (농업용 저수지 내 침강지의 설치유형에 따른 수질정화효율 평가)

  • Jang, Jeong-Ryeol;Choi, Sun-Hwa;Nam, Gui-Sook;Kwun, Soon-Kuk
    • Journal of Korea Water Resources Association
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    • v.38 no.8 s.157
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    • pp.665-674
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    • 2005
  • The aim of this study is to evaluate 3 types of sedimentation basins: dredging, shield skirt and auxiliary dam, constructed at inlets of two irrigation reservoir and to estimate the most beneficial type and fitted size, SAR(surface to area ratio), for pollutant removal efficiency(RE). For this, RE of major water quality items and change of physicochemical properties in sediments before and post construction of sedimentation basin(SB) were investigated. RE depended on SB types, water quality items and survey times with wide range from $-87\%$ to $92\%$. Long term overall removal efficiency by ROC(regression of concentration) method were $18\%$ in dredging, $29\%$ in shield skirt and $42\%$ in auxiliary dam type. There was a change of physicochemical properties in sediments at auxiliary dam type, while a slight change at dredging and shield skirt type. In comparison to RE, SAR and hydraulic retention time at 3 types of SB, auxiliary dam type was the most beneficial one. Thus, it is recommended that SB would be constructed in completely separated structure from water body of a reservoir with SAR ranged from 0.7 to $1.0\%.$

Comparison of Efficiencies Among Hand Sorting, Vermifuge Application and Combined Methods for Earthworm Sampling in the Field (수작업, 기피제처리, 수작업과 기피제 혼합처리에 의한 지렁이 채집효율 비교)

  • Bae, Yoon-Hwan;Na, Young-Eun
    • The Korean Journal of Soil Zoology
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    • v.4 no.2
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    • pp.81-85
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    • 1999
  • Efficiencies of hand sorting, vermifuge application and combined methods of them for sampling earthworms in the field were compared. 1) hand sorting : sampling unit of soil (50 cm${\times}$50 cm${\times}$30 cm, width${\times}$length${\times}$depth) was dug out and earthworms were sorted by hands. 2) Vermifuge application : Solution of mustard, pepper or formalin was treated onto the soil surface of smpling unit (50 cm${\times}$50 cm, width${\times}$length). 3) Combined method : In a sampling unit of soil (50 cm${\times}$50 cm${\times}$30 cm, width${\times}$length), hand sorting was carried out into the depth of 10 cm or 15 cm and then vermifuge was treated. Earthworms were collected more in numbers by hand sorting than vermifuge application although it was much more time-consuming and labor intensive. Efficiency of mustard to extract earthworms was as same as formalin but much better than that of pepper. Combined method of hand sorting with mustard treatment was more efficient than vermifuge applications and other combined methods. And it could collect earthworms as many as hand sorting, but was much less time-consuming and labor-intensive than hand sorting. Thus combined method of hand sorting (to the depth of 15 cm) with mustard treatment could be recommended for the sampling of earthworms in the field.

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Effects of Planting Density and Fertilizer Level on the Growth, Yield, Quality and Nitrogenous Compounds of Burley Tobacco (재식밀도 및 시비량이 버어리종 잎담배의 생육, 수량, 품질 및 질소화합물에 미치는 영향)

  • Kim, Sang-Beom;Han, Chul-Soo;Ryu, Ik-Sang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.32 no.1
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    • pp.40-47
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    • 1987
  • Under the different conditions of planting density and compound fertilizer level, some agronomic and chemical characteristics of burley tobacco were investigated from 1982 to 1984. Leaf area and dry leaf weight per plant, crop growth rate, relative growth rate and net assimilation rate for 40-60 days after transplanting were higher with increasing plant spacing and fertilizer, but leaf area index was lower with increasing plant spacing. At topping stage, the leaf size was increased with increasing plant spacing and amount of fertilizer applied and the stem diameter was increased by increasing plant spacing. Leaf area, leaf weight per plant and weight per unit leaf area of harvested leaf were higher when plant spacing and fertilizer increased. It was estimated that the optimum plant spacing was 105cm x 34cm and level of com-pound fertilizer (N-P$_2$ O$\sub$5/ -K$_2$O =10-10-20) was 263kg/l0a for high yield. There were trends toward increase the contents of total alkaloid and total nitrogen with increasing plant spacing and fertilizer application. There was significant positive correlation between plant spacing and total nitrogen, and between fertilizer application and total nitrogen. The plant spacing of 105cm x 35 to 40cm and 227.5kg/l0a of fertilizer level may be profitable for farm economy and the low nitrogenous leaf.

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Self -Tuning Scheme for Parameters of PID Controllers by Fuzzy Inference (퍼지추론에 의한 PID제어기의 파라미터 Tuning의 구성)

  • 이요섭;홍순일
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.4
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    • pp.52-57
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    • 2003
  • A PID parameter tuning method was presented by the fuzzy singleton inference, based on step response-shaping of plant and experience knowledge of expert. The parameter-tuning has tow levels. The higher level determines modified coefficients for the controller based on operator's tuning know-how for characteristics of plant which can not be modeled. The lower level determines specified coefficients based on characteristics of response by Ziegler-Nickel's bounded sensitivity method. The last level parameters tuning of a PID controller is adjusted which the modified and specified coefficients makes adjustment rule, and is adjusted the proper value to each parameters by fuzzy singleton inference. Moreover, proposed the tuning method can reflex exporter knowledge and operator's tuning know-how and fuzzy singleton inference is rapidly operated.

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A Study on the Revision of Staffing Standards for Korean Public Libraries (공공도서관 직원배치기준 개정안 연구)

  • Yoon, Hee-Yoon
    • Journal of the Korean Society for Library and Information Science
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    • v.46 no.1
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    • pp.55-76
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    • 2012
  • Regardless of which country, all public libraries need facilities, collections, and funds. But how well the library system succeeds depends on the staff committed to providing the highest possible level of service to the community. The public library, therefore, should employ the appropriate number of full-time staff. In order to warrant such a work force, this study analyzed the juridical justification, logical validity, realistic fitness, and usefulness of current legal and recommended staffing standards. This study also suggested the revisions of total space of buildings and collection size as crucial variables for library staffing, division of legal service populations, basic staffing level, and additional staff in proportion to service populations for public libraries in Korea.

Enlargement of Harbour limit for expanding Anchorages in Ulsan Port (울산항 정박지 확충을 위한 항계 확장에 관한 연구)

  • Yun, Gwi-Ho;Kim, Bu-Young;Lee, Yun-Sok
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2010.04a
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    • pp.169-170
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    • 2010
  • Ulsan Port is in the situation which the harbour limit and anchorages are less narrow than other trading ports and the occurrence probability of marine accidents is high due to heavy marine traffic Especially, the shortage of anchorages will become worse in case that the number of inbound and outbound vessels increases according to the development of Ulsan New Port. We will find and suggest the plan to enlarge the harbour limit essentially needed to expand anchorages in this research The reasonable type of harbour limit which is based on the survey by a group of experts, was determined after the decision of the range of harbour limit to accommodate the relevant anchorages.

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Review of Applicability of Huff's method in Korea (Huff방법의 국내유역 적용성 검토)

  • Jang, Su-Hyung;Yoon, Jae-Young;Yoon, Yong-Nam
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1855-1859
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    • 2006
  • Huff(1967)의 연구배경과 지형 및 강우특성을 국내유역과 비교하고 Huff(1967) 방법을 국내에 적용한 건교부(2000) Huff의 한계점을 파악하였으며, 국내 강우가 갖는 지속시간별 시간분포특성을 검토함으로써 국내유역에 적합한 Huff 방법의 개선방안을 위한 기초연구를 목표로 하였다. Huff(1967)의 연구유역과 본 연구유역의 점강우가 갖는 특성에는 차이가 있었다. 그리고 건교부(2000) Huff 방법은 관측소별로 분석되어 유역을 대표하는 누가곡선의 채택에 어려움을 갖게 되며, 이용된 강우사상은 강우총량의 크기에 관계없이 모든 자료를 이용하여 점우량 25.4mm이 상을 대상으로 비교한 결과와 차이가 있는 것으로 분석되었다. 또한, 본 연구 대상유역의 점강우와 면적강우에서 지속기간별로 강우의 시간분포 특성이 다양한 것으로 분석되었으며, 이는 K-S 검정결과 5% 유의수준에서 지속기간별로 작성된 일부 누가곡선이 전 지속기간에 대해 작성된 누가곡선과 유의하지 않는 것으로 분석되어 지속기간별 시간분포 특성이 통계학적으로 입증되었다. 따라서 Huff(1967) 방법을 국내유역에 적용하기 위해서는 적정 수준 이상의 총량을 갖는 강우사상을 대상으로 유역의 대표성, 강우의 지속기간별 특성이 반영된 누가곡선이 작성 되어야 할 것으로 판단되었다.

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Estimate of Optimum Plot Size and Shape for Rape Yield Trials (유채 수량검정시험구의 크기와 모양에 대한 변이계수관계)

  • 권병선;문병탁;이용보
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.23 no.1
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    • pp.51-54
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    • 1978
  • 3∼6m long plot with 3-4 replications will be practical for yield trials in the early hybrid generations. The C. V. values with 9m long plot was about 6.6% in variety Yudal and 13.9% in 12m plot. These results indicate that 9-12m plot with 3-4 replications could be employed in securate yield test in the advanced generations.

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Thermal Characteristics of Cross-flow Small Scale Heat Exchanger (소형 직교류 열교환기의 열적 특성에 관한 연구)

  • Kum, Sungmin;Yu, Byeonghun;Rhee, Kwan-Seok;Lee, Seungro
    • Journal of Energy Engineering
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    • v.22 no.1
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    • pp.44-50
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    • 2013
  • This study was experimentally investigated NOx and CO emissions characteristics with various equivalence ratios using premixed type of burner installed small heat exchanger. The effectiveness of heat exchanger and the entropy generation number were also calculated. As results, the heat transfer rate increases with increasing equivalence ratio due to increase the flame temperature. According to the emission characteristics and the effectiveness, the optimal operating equivalence ratio is 0.75 in the range of this experiment. Consequently, the area of the heat exchanger should be increased to reduce the entropy generation number and to increase the effectiveness.

A Study on the Qptimum Size of Master Bedroom Walk-In Closet in Apartments (아파트 드레스룸의 적정 수납장 크기에 관한 연구)

  • Kim, Jea-Heun;Seo, Hyun
    • Korean Institute of Interior Design Journal
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    • v.20 no.5
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    • pp.152-159
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    • 2011
  • Housing construction companies have been providing master bedroom walk-in closet as a selling point in modest sized apartments as small as 74m$^2$. It is noticeable that master bedroom walk-in closet in apartments provided by public sectors showed much variety in its size. This study tries to set up the guide line of master bedroom walk-in closet size. It is quite reasonable to assume that the biggest space-occupiers in walk-in closet are blankets and clothing. The survey conducted in this study shows that the number of clothes people keep in their closet does not show any significant difference regardless of square footage of their apartments. 34.7% of respondent answered they keep about 50-60 clothes using coat hangers, where 20-30 of those are winter clothes. It is calculated the required optimum length of the walk-in closet is 3.8m$^2$. Considering the most popular longitudinal dimension of master bedroom, 3.9m, and the space needed to accommodate blankets, it can be concluded that the required length of storage in master bedroom walk-in closet is 2.1m. The length can be adjusted reflecting the length of the master bedroom.