• 제목/요약/키워드: HR

검색결과 10,102건 처리시간 0.037초

A new insight into design of acoustic liner arrays arrangement in the presence of a grazing flow

  • Hadi Dastourani ;Iman Bahman-Jahromi
    • Advances in Computational Design
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    • 제8권4호
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    • pp.273-293
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    • 2023
  • This study evaluated the acoustic performance of two configurations of serial HR arrays and lined HR arrays in the presence of grazing flow using a 3D numerical simulation. The dual, triple, and quad HR arrays were compared to the conventional HR array. The simulation results showed that the number of resonant frequencies increased with the number of serial HR arrays. The CTL did not significantly change with the number of serial HR arrays. The acoustic performance of the two, three, and four-lined HR arrays was compared to the conventional HR array. The results showed that the resonant frequency and TLmax increased with the number of lined HR arrays. The CTL also increased with the number of lined HR arrays. The effect of the grazing flow Mach number (Ma) was investigated on the four-lined HR array configuration and compared to the conventional HR configuration. TLmax and CTL decreased for both configurations with increasing Ma. The four-lined HR array configuration had significantly better acoustic performance than the conventional HR configuration. The TLmax and CTL increased by more than 300% when the configuration was changed from the conventional HR to the four-lined HR array at Ma = 0.The increment percentage decreased with increasing Ma.

HR Practices of IT-Based Companies in Korea

  • CHO, Yonjoo
    • Educational Technology International
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    • 제7권2호
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    • pp.69-92
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    • 2006
  • The research question in this study was to see whether there were similarities and differences in HR practices of IT-based companies in Korea. Interviews with 12 HR executives and a survey of 51 IT-based companies showed that there were IT industry-specific HR practices, but no group differences except one. The only one difference between two groups (small- and medium-sized firms versus multinational corporations) indicated that the latter was better positioned in various HR practices. Four HR themes emerged from analyses of interviews and a survey data: business environment, workforce management, HR practices, and HR for competitive advantage. The fact that none from large companies was found to have female HR executive calls for an in-depth study of what is occurring and what could be done to better the workplace in terms of diversity. A large-scale study using diverse methods in the future will produce more meaningful findings on HR practices in IT-based firms in Korea.

갯벌의 오염물질 정화능력 평가 (Evaluation on the Purification Capacity of Pollutants in the Tidal Flat)

  • 유선재;김종구
    • 한국수산과학회지
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    • 제32권4호
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    • pp.409-415
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    • 1999
  • 우리나라 갯벌의 오염물질 정화능력을 알아보기 위해 물리, 화학적 특성이 서로 다른 충남 서천군 춘장대 갯벌, 전북 옥구군 어은리 갯벌 그리고 전북 계화도 갯벌을 채취하였다. 실험은 갯벌의 물리화학적 성분분석을 행하고, 갯벌을 채운 반응기를 이용해 유기물, 영양염류 및 중금속의 정화능력을 평가해 보았다. 1. 3개 갯벌의 입도분석 결과 어은리 갯벌이 니질의 함량이 $98.8\%$로 가장 높고, 춘장대 갯벌은 모래성분이 $97.84\%$로 가장 높았다. 유기물함량 (IL, COD, POC)는 니질 함량이 높은 어은리 갯벌에서 다른 두 갯벌 보다 2$\~$8배 이상 높았다. 2. 갯벌의 유기물 정화능력을 COD로 계산한 결과, 어은리 갯벌 0.75kg/ha/12hr, 계화도 갯벌 0.60kg/ha/12hr 그리고 춘장대갯벌 0.55 kg/ha/12hr 이었고, 3개 갯벌의 1일 평균 COD 정화능력은 1.27kg/ha/day이었다. 앞의 결과를 새만금 간척사업으로 소멸될 면적 (20000ha)에서 제거될 수 있는 유기물량으로 환산하면 25.4 ton/day로 계산되었다. 3. 갯벌의 영양염류 정화능력은 인산 인의 경우, 계화도에서 0.21 kg/ha/12hr, 어은리에서 0.39kg/ha/12hr, 그리고 춘장대에서 0.22kg/ha/12hr였고, 질산질소는 계화도에서 0.53kg/ha/12hr, 어은리에서 0.74kg/ha/12hr 그리고 춘장대에서 0.43kg/ha/12hr 이었다. 4. 갯벌의 중금속 정화능력은 Cu의 경우, 계화도 갯벌 88.9g/ha/12hr, 어은리 갯벌 89.1 g/ha/12hr 그리고 춘장대 갯벌 55.3g/ha/12hr이고 Pb은 계화도 갯벌 11.0g/ha/12hr, 어은리 갯벌 18.0g/ha/12hr 그리고 춘장대 갯벌 13.1g/ha/12hr그리고 Cd은 계화도 갯벌 1.7 g/ha/12 hr, 어은리 갯벌 2.6 g/ha/12 hr 그리고 2.1 g/ha/12 hr 이었다. 이상의 결과에서 갯벌의 정화능력은 니질의 함량이 많은 어은리 갯벌이 모래로 이루어진 춘장대 갯벌보다 상대적으로 높은 정화능력을 나타내어, 갯벌의 물리, 화학적 성상이 중요한 역할을 하는 것으로 나타났다.

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용매에 따른 카레 향신료 추출물의 항산화 효과 및 혼합효과 (Antioxidant and Mixture Effects of Curry Spices Extracts Obtained by Solvent Extraction)

  • 안채경;이영철;염초애
    • 한국식품과학회지
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    • 제32권3호
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    • pp.491-499
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    • 2000
  • 카레분의 단품향신료와 카레분(curry powder)을 메탄올, 에틸아세테이트, 헥산으로 추출하여 수율, 항산화 효과, 총페놀함량, 총토코페롤 함량을 측정하였다. 메탄올, 에틸아세테이트, 헥산의 추출 수율은 각각 $6.4{\sim}42.9$, $3.9{\sim}26.2$, $1.6{\sim}29.2\;%$로 극성이 높아질수록 수율이 증가하였다. 미강유의 각 용매별 추출물을 1,500ppm 첨가하여 Rancimat로 유도기간을 측정한 결과 메탄올 추출물은 rosemary, sage, ginger, turmeric, nutmeg 순으로 우수하였고, 에틸아세테이트 추출물은 rosemary, sage, oregano, thyme, ginger의 순이었으며 헥산 추출물은 rosemary, sage, oregano, ginger, thyme 순이었다. 1,500ppm을 미강유에 첨가하였을 때 BHT보다 유도기간이 길게 나타난 향신료는 3가지 용매 추출물에서 공통적으로 rosemary, sage, ginger, oregano, thyme이었으며 이들 향신료를 200, 500, 1,000, 1,500, 2,000 ppms 농도로 미강유에 첨가한 후 유도기간을 측정한 결과 rosemary와 sage는 헥산 추출물 2,000ppm에서, ginger는 메탄올 추출물 2,000ppm에서 우수한 효과를, oregano와 thyme은 에틸아세테이트 추출물이 1,500ppm과 2,000ppm에서 큰 차이 없이 우수한 효과를 나타내었다. Rosemary의 혼합에 따라 ginger와 thyme의 항산화 효과가 크게 증가함을 알 수 있었으나 상승효과라기 보다는 rosemary로 인한 유도기간의 연장 효과였다. 총페놀 함량은 메탄올 추출물은 $17,924{\sim}801\;mg%$, 에틸아세테이트 추출물은 $13,893{\sim}57\;mg%$, 헥산 추출물은 $6,864{\sim}12\;mg%$이었으며 총페놀함량과 항산화 효과가 일치하지는 않았다. 토코페롤의 경우 oregano가 3194.8mg%로 가장 높았으며, sage 1014.8 mg%, rosemary 571.1 mg%, thyme 187 mg%였고 ginger에서는 토코페롤이 검출되지 않았으며 토코페롤함량과 항산화 효과는 뚜렷한 상관관계가 발견되지 않았다.

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최근 기상특성과 재해발생이 고려된 호우특보 기준 개선 (An improvement on the Criteria of Special Weather Report for Heavy Rain Considering the Possibility of Rainfall Damage and the Recent Meteorological Characteristics)

  • 김연희;최다영;장동언;유희동;진기범
    • 대기
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    • 제21권4호
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    • pp.481-495
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    • 2011
  • This study is performed to consider the threshold values of heavy rain warning in Korea using 98 surface meteorological station data and 590 Automatic Weather System stations (AWSs), damage data of National Emergency Management Agency for the period of 2005 to 2009. It is in need to arrange new criteria for heavy rain considering concept of rainfall intensity and rainfall damage to reflect the changed characteristics of rainfall according to the climate change. Rainfall values from the most frequent rainfall damage are at 30 mm/1 hr, 60 mm/3 hr, 70 mm/6 hr, and 110 mm/12 hr, respectively. The cumulative probability of damage occurrences of one in two due to heavy rain shows up at 20 mm/1 hr, 50 mm/3 hr, 80 mm/6 hr, and 110 mm/12 hr, respectively. When the relationship between threshold values of heavy rain warning and the possibility of rainfall damage is investigated, rainfall values for high connectivity between heavy rain warning criteria and the possibility of rainfall damage appear at 30 mm/1 hr, 50 mm/3 hr, 80 mm/6 hr, and 100 m/12 hr, respectively. It is proper to adopt the daily maximum precipitation intensity of 6 and 12 hours, because 6 hours rainfall might be include the concept of rainfall intensity for very-short-term and short-term unexpectedly happened rainfall and 12 hours rainfall could maintain the connectivity of the previous heavy rain warning system and represent long-term continuously happened rainfall. The optimum combinations of criteria for heavy rain warning of 6 and 12 hours are 80 mm/6 hr or 100 mm/12 hr, and 70 mm/6 hr or 110 mm/12 hr.

HR Plate의 강박스거더 적용 연구 (Application of HR-Plate in Steel Box Girder)

  • 이성행;함형길;김경남;정경섭
    • 한국공간구조학회논문집
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    • 제7권4호
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    • pp.63-72
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    • 2007
  • 국내외적으로, 특히 중국에서 철강산업의 수요증대로 철판의 가격이 다른 재료에 비하여 급격하게 상승되고 있다. 열연 코일로부터 만들어지는 HR Plate는 후판에 비하여 가격이 저렴하다. 본 연구에서는 HR Plate의 재료특성을 검토하고, 강교에서 부부재와 주부재로서 HR Plate의 적용성을 연구하였다. 연구결과 일반 후판과 HR Plate는 두께 22mm까지 절단, 조립성, 용접 등의 특성에 있어서 차이가 없었다. 강박스교량의 부부재로서 사용율과 손실율은 각각 $10{\sim}15%,\;10{\sim}l5%$로 조사되었다.

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체외성숙 시간이 한우 수정란 생산에 미치는 영향 (Effects of Maturation Time on In-vitro Production of Korean Native Cow Embryos)

  • 박용수;최수호;한진철;박흠대;변명대
    • 한국가축번식학회지
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    • 제27권1호
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    • pp.35-44
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    • 2003
  • The present study was performed to investigate the first polar body(PB) extrusion during in-vitro maturation(IVM) and to examine the effect of different maturation time on the embryo development of Korean Native Cows(KNC) with regard to blastocyst(BL) cell numbers and pregnancy rates. PB extrusion did not take place for the first 12 hours(hr) of IVM, and most of KNC oocytes extruded PB from 14 to 20 hr after the onset of maturation. There was no significant difference in cleavage and 8-cell stage rates among the treatment groups, but BL and BL/8-cell rates were significantly higher(P<0.05) in 18 hr maturation group(31.0$\pm$5.7 and 82.0$\pm$5.1%) than 22 and 24 hr maturation group. The proportion of BL formed on day 7 and 8 was significantly higher(P<0.05) in 18 hr maturation group(85%) than in 24 hr maturation group(55%). There was a significant difference(P<0.05) in inner cell mass, trophectoderm and total cell number between day 7 BL produced by in-vivo and IVM 18 hr and day 8 BL produced by IVM 18 hr and 24 hr. Pregnancy rates are also significantly higher(P<0.05) in in-vivo(56.3%) and IVM 18 hr day 7(50.0%) group than day 8 treatment groups(18 hr: 16.7%, 24 hr: 10.5%). These results suggest that KNC oocytes achieve developmental competency within 20 hr of IVM, and "short" IVM (18 hr) is more effective than "long" IVM(24 hr) in embryo development rates, BL cell numbers and pregnancy rates.

Evaluation of the Home-based Rehabilitation Program Based on CBR Model Through In-depth Interviews With Visiting Physical Therapists

  • Lee, Minyoung;Chung, Jinjoo;Hong, Hye Jung;Yoon, Bum Chul
    • The Journal of Korean Physical Therapy
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    • 제27권1호
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    • pp.68-77
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    • 2015
  • Purpose: This study was conducted in order to explore home visiting therapists' self-perceived role, problems, and supplement points of the home-based rehabilitation (HR) program based on the community-based rehabilitation (CBR) model. Methods: Four home visiting physical therapists, who conducted the HR program, participated in this study. After completion of the HR program, in-depth interviews were conducted using a semi-structured questionnaire for participants to explore their self-perceived role, problems, and supplement points of the HR program. Results: Participants regarded the role of the HR program as for "the linkage between recipient & society", "maintenance & improvement of recipients' physical function", and "education of recipient about the way of self rehabilitation". The problems and supplement points were derived from all phases of the HR program, including "human & material resources", "training program for human resources for HR service", "selection of recipient of HR service", "contents of the intervention for HR service", and "duration of HR service". Conclusion: These findings indicate that participants well recognized the intention of the HR program based on the CBR model, and suggest that high-quality human resources with rich expertise and experiences, a training program for HR service led by experts, and selection of recipients led by experts are necessary for an effective HR program. In addition, strategies and capacities specified to HR service should be identified, and applied to the training program for human resources for HR service. The results of this study could provide useful information when the government decides on the next guideline for home visiting health service.

적색 LED(660nm)의 광중단 처리에 따른 국화 '백마'와 '신마'의 화아분화 및 생육특성 (Effect of night break treatment using Red LED (660 nm) on flower bud initiation and growth characteristics of chrysanthemum cv. 'Baekma', and cv. 'Jinba')

  • 권영순;최성열;길미정;유봉식;정재아;박상근
    • 농업과학연구
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    • 제40권4호
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    • pp.297-303
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    • 2013
  • This study was carried out to examine the effect of Red LED (660 nm) and fluorescent lamp for night break (NB) treatments of each 3 hours (22:30-01:30), 4 hours (22:00-02:00) and 5 hours (21:30-:02:30) per day for 53 days on flower bud initiation and growth in Chrysanthemum cv. 'Baekma' and cv. 'Jinba'. The days to flower budding after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (21.0 days) and 5 hr (20.5 days) NB, and it was shorter at Red LED 3 hr (14.2 days). The days to flowering after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (54.0 days), 5 hr (53.5 days) NB, and Red LED 5 hr (53.3 days), and it was shortest at Red LED 3 hr (50.2 days) NB treatment among all treatments. The days to flower budding after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (20.6 days) and was shorter at Red LED 3 hr (14.1 days) among all treatments. Similarly, the days to flowering after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (55.3 days) and was shortest at Red LED 3 hr (50.2 days) among all treatments. Therefore, inhibition of flower bud initiation was the most effective under fluorescent lamp 4 hr treatment. The length of cut flower of 'Baekma' was increased by fluorescent lamp 4 hr, 5 hr, and Red LED 5 hr, but of 'Jinba' was longer at LED 4 hr and 5 hr treatment. The weight of cut flower of 'Baekma' was heaviest at fluorescent lamp 5 hr treatment and was at Red LED 5hr treatment for 'Jinba' even though there was not statistically significant difference between 'Baekma' and 'Jinba'. Consequently, under fluorescent lamp 4 hr for night break was the most effective on flower bud initiation, flowering inhibition and cut-flower characteristics in 'Baekma' and 'Jinba'.

갑상선암의 고용량 $^{131}I$ 치료 시 입원기간의 최적화방안 연구 (A Study on Ways to Optimize the Period of Hospitalization During High-Dose $^{131}I$ Treatment of the Thyroid Cancer)

  • 백성민;고성진;김창수;김정훈;강세식
    • 대한방사선기술학회지:방사선기술과학
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    • 제33권3호
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    • pp.269-276
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    • 2010
  • 본 연구는 고용량 방사성옥소 치료환자의 선량률을 거리와 시간대별로 산출하여 방사성옥소 치료를 위한 입원기간의 최적화와 개선방안을 제한 하고자 하였다. 그 결과 100 mCi 고용량 옥소치료환자의 24시간 후에 배꼽에서 $1,035{\mu}Sv/hr$, 50 cm에서 $109{\mu}Sv/hr$, 100 cm에서 $33{\mu}Sv/hr$로 감쇠 되었다. 150 mCi 고용량 옥소치료환자의 24시간 후에 배꼽에서 $637{\mu}Sv/hr$, 50 cm에서 $100{\mu}Sv/hr$, 100 cm에서 $40{\mu}Sv/hr$로 감쇠 되었다. 180 mCi 고용량 옥소치료환자의 24시간 후에 배꼽에서 $1,251{\mu}Sv/hr$, 50 cm에서 $140{\mu}Sv/hr$, 100 cm에서 $56{\mu}Sv/hr$로 감쇠 되었다. 퇴원기준을 미국 원자력 규제위원회 고시에 $70.4{\mu}Sv/hr$이므로 본 연구 결과보다 빠른 퇴원이 가능하다. 치료 환자들의 계속적인 증가 추세로 볼 때 치료병실의 부족을 해소 할 수 있다.