• 제목/요약/키워드: Cross-National study

검색결과 4,503건 처리시간 0.034초

교차자화 포화효과에 의한 발전기 정수와 간략모델에 미치는 영향에 관한 연구 (A study on the effect of cross magnetization to the generator parameters and simplified linear model)

  • 김덕영;권세혁
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 C
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    • pp.1236-1238
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    • 1999
  • This paper presents an effect of cross magnetization to the generator simplified linear model which is used for multi-machine power systems. The formulae of reactances and time constant with saturation effect are presented. The simulation results show that cross magnetization has an effect which can not be ignored, to the reactances, time constant and eigenvalues in one machine infinite bus system of simplified linear model.

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제주재래흑돼지×Landrace F2 집단의 성장형질에 대한 교배조합의 효과 (Effect of Mating Types on the Growth Traits of F2 Population between Landrace and the Jeju Native Black Pigs)

  • 강용준;조상래;정동기;이재봉;박희복;조인철;한상현
    • 한국수정란이식학회지
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    • 제31권1호
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    • pp.65-72
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    • 2016
  • This study was conducted to examine effects of mating type on the growth traits in an $F_2$ population produced by reciprocal intercrosses between Landrace and the Jeju Native Black pig (JBP). The $F_2$ progeny were produced by two different mating types based on the grand dams of founder breeds JBP (Cross_1) and Landrace (Cross_2). The body weights at 21 days after birth (BW21D) was significantly different between Cross_1 and Cross_2 (P<0.05), showing that the BW21D of Cross_1 has about 0.25 kg heavier than Cross_2. The significant differences were found between males and females for the growth traits including the body weights (BWB, BW21D, BW70D and BW140D) and average daily gains (ADG, eADG and lADG) (P<0.05). Males were heavier BWB, BW21D and BW140D levels, and higher ADG and lADG levels than females. On the other hand, females had heavier BW70D and higher eADG levels than those of males. When considering the mating types and sex simultaneously the Cross_2 males had the heaviest BW140D among the combinations of cross and sex. In conclusion, it is desirable to choose Landrace as grand dams in the reciprocal intercrosses between Landrace and JBP for producing their progeny construction and to plan the production of $F_2$ males for industrial purposes. These results suggested that it may be one of useful strategies to improve the productivity through out selection of the mating type of founder breeds and the progeny sex, especially in Landrace, JBP and their related populations.

Innervated Cross-Finger Pulp Flap for Reconstruction of the Fingertip

  • Lee, Nae-Ho;Pae, Woo-Sik;Roh, Si-Gyun;Oh, Kwang-Jin;Bae, Chung-Sang;Yang, Kyung-Moo
    • Archives of Plastic Surgery
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    • 제39권6호
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    • pp.637-642
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    • 2012
  • Background Fingertip injuries involving subtotal or total loss of the digital pulp are common types of hand injuries and require reconstruction that is able to provide stable padding and sensory recovery. There are various techniques used for reconstruction of fingertip injuries, but the most effective method is functionally and aesthetically controversial. Despite some disadvantages, cross-finger pulp flap is a relatively simple procedure without significant complications or requiring special techniques. Methods This study included 90 patients with fingertip defects who underwent cross-finger pulp flap between September 1998 and March 2010. In 69 cases, neurorrhaphy was performed between the pulp branch from the proper digital nerve and the recipient's sensory nerve for good sensibility of the injured fingertip. In order to evaluate the outcome of our surgical method, we observed two-point discrimination in the early (3 months) and late (12 to 40 months) postoperative periods. Results Most of the cases had cosmetically and functionally acceptable outcomes. The average defect size was $1.7{\times}1.5$ cm. Sensory return began 3 months after flap application. The two-point discrimination was measured at 4.6 mm (range, 3 to 6 mm) in our method and 7.2 mm (range, 4 to 9 mm) in non-innervated cross-finger pulp flaps. Conclusions The innervated cross-finger pulp flap is a safe and reliable procedure for lateral oblique, volar oblique, and transverse fingertip amputations. Our procedure is simple to perform under local anesthesia, and is able to provide both mechanical stability and sensory recovery. We recommend this method for reconstruction of fingertip injuries.

Distribution of S-alleles among Korean Apples by PCR and Cross-pollination

  • Heo, Seong;Kwon, Soon-Il;Hwang, Jeong-Hwan;Shin, Yong-Uk;Kim, Mok-Jong;Park, Bong Ju;Oh, Sung-Il;Oh, Young-Jae;Kim, Daeil
    • 원예과학기술지
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    • 제30권6호
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    • pp.757-763
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    • 2012
  • To acquaint correct information about the fertilizability and analyze S-allele based genetic diversity among Korean apples, we investigated self-incompatibility genotypes by PCR and cross-pollination tests in field. As a consequence, S-genotypes of Korean apples were distributed within narrow genetic diversity as $S_1S_3$ for 'Hongro' and 'Saenara'; $S_1S_9$ for 'Gamhong' and 'Manbok'; $S_3S_5$ for 'Seokwang'; $S_3S_9$ for 'Sunhong', 'Seohong', 'Chukwang', and 'Hwahong'. Coupled with cross-pollination experiments in field, our results provide support for the view that apples are fully compatible when both of their S-loci differ and semi-compatible when they carry one different and one identical S-locus. Furthermore, the results of this study indicate that S-alleles have to be extended to various genotypes for Korean apple breeding.

합판을 코어로 사용한 교호 집성재의 물리·기계적 성질 (Physical and Mechanical Properties of Cross Laminated Timber Using Plywood as Core Layer)

  • 최철;육초롱;류지창;박재영;이창구;강석구
    • Journal of the Korean Wood Science and Technology
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    • 제43권1호
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    • pp.86-95
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    • 2015
  • 본 연구는 기존에 제조되었던 교호집성재의 휨강도의 단점을 보완하고 새로운 특성을 가진 교호 집성재 즉, 합판을 코어로 이용한 집성재가 가진 기계적강도의 효과를 알아보기 위해 수행되었다. 집성재와 합판의 구성 방법, 적층 방향에 따라 그 값을 비교하였으며, 그에 따른 휨강도와 탄성계수를 측정하여 분석한 결과, 중심부를 집성판과 합판을 혼합하여 구성한 합판 코어 집성재의 휨강도(MOR) 값이 59.6% 강도가 향상되어 교호집성재구조 대조군보다는 우수하고, 집성재구조 대조군과는 유사한 강도를 나타냈다. 휨탄성계수(MOE)는 합판 코어 집성재의 구조 및 적층 방향성에 상관없이 모두 집성재구조 대조군과 유사한 MOE 값을 나타냈다. 치수 안정성 실험에서는 합판을 코어에 사용한 합판코어 집성재가 합판 사용으로 인하여, 수축 팽창률 모두 집성재와 교호집성재구조 대조군에 비해서 더 안정적인 것으로 나타났다.

QTL Mapping of Agronomic Traits in an Advanced Backcross Population from a Cross between Oryza sativa L. cv. Milyang 23 and O. glaberrima

  • Kang, Ju-Won;Suh, Jung-Pil;Kim, Dong-Min;Oh, Chang-Sik;Oh, Ji-Min;Ahn, Sang-Nag
    • 한국육종학회지
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    • 제40권3호
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    • pp.243-249
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    • 2008
  • In the previous study, 141 $BC_3F_2$ lines from a cross between the Oryza sativa cv. Milyang 23 and O. glaberrima were used to identify favorable wild QTL alleles for yield component traits. In this study, we carried out QTL analysis of four grain morphology as well as four yield component traits using 141 $BC_3F_5$ lines from the same cross and compared QTLs detected in two different generations. The mean number of O. glaberrima segments in the 141 $BC_3F_5$ lines ranged from 1 to 13 with 2.69 and 5.71 of the average means of homozygous and heterozygous segments, respectively. There was a three-fold difference in the number of QTLs detected for four traits commonly evaluated in two generations (seven QTLs in the $BC_3F_5$ vs 21 in the $BC_3F_2$ population). The percentages of the phenotypic variance explained by QTLs in the BC3F5 population were similar to or less than those in the $BC_3F_2$ population. This is probably due to the difference in the genetic composition of two populations and the environmental effects. The locations of the QTLs commonly detected in both generations were in good agreement except for one QTL for spikelets per panicle. The yield QTL, yd3 was colocalized with the spikelets per panicle, spp3. Yield increase at this locus is due to the increase in spikelets per panicle, because both traits were associated with increase in spikelets per panicle and yield due to the presence of an O. glaberrima allele. Clusters of QTLs for grain morphology traits were observed in two chromosome regions. One cluster harboring five QTLs near SSR markers RM106 and RM263 was detected on chromosome 2. This population would serve as a foundation for development of the introgression line population from a cross between Milyang 23 and O. glaberrima.

Influence of guide vane shape on the performance and internal flow of a cross flow wind turbine

  • Son, Sung-Woo;Singh, Patrick Mark;Choi, Young-Do
    • Journal of Advanced Marine Engineering and Technology
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    • 제37권2호
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    • pp.163-169
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    • 2013
  • In order to make the vertical-axis cross flow wind turbine commercially feasible, a guide vane is adopted and the effect of the guide vane shape is examined in order to improve the wind turbine performance. CFD analysis on the performance and internal flow of the turbine is carried out for the wind turbine model. The result shows that when the guide nozzle is installed, almost over two times of power coefficient are achieved in comparison with the case of no guide nozzle installation. The guide nozzle acts as a role of suppressing the flow resistance at the blade passage, which is found when the guide nozzle is installed. Moreover, in this study, two kinds of the guide vane with a straight type and a curved type are adopted and compared. The curved guide vane nozzle produces higher power coefficient in comparison with that of straight guide vane nozzle.

등방성 빔 단면과 비등방성 공간 부분 코히어런스 특성을 갖는 가우시안 셀 모델 빔의 구현에 대한 해석적 연구 (Analytic study on the realization of partially coherent Gaussian Schell-model beams with isotropic cross section and anisotropic degree of coherence function)

  • 김휘;김태수;최경식;이병호
    • 한국광학회지
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    • 제15권3호
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    • pp.200-213
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    • 2004
  • 등방성 빔 단면과 비등방성 공간 부분 코히어런스 특성을 갖는 가우시안 셀 모델 빔의 구현에 대하여 연구하였다. He-Ne 레이저의 가우시안 빔이 회전하는 홀로그래픽 확산판을 통과하면서 생성된 확산광을 등방성 빔 단면과 비등방성 공간 코히어런스 특성을 갖는 가우시안 셀 모델 빔으로 만드는 광학계를 제안하였다. 광학계의 해석적 설계 방정식을 유도하였고 이를 사용한 설계 예를 제시하였다.

스트럿 부재와 융합단면을 이용한 기둥-보 강결 구조물 해석 (Analysis of Beam-column Joints in a Structure using Strut Members and Composite Section)

  • 조재형;송재호
    • 한국산업융합학회 논문집
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    • 제23권2_2호
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    • pp.289-299
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    • 2020
  • The composition of convergence cross-section of the material is a technique that provides reasonable design and construction of structures. It is frequently used in medium-sized bridges and architectural structures. However, the structural behavioral spare capacity enhancement of the structure by the application of the convergence cross-section is still limited by the expandability due to the limiting state of each material. In order to overcome these limitations, this study reasonably analyzed the construction stages before and after the convergence cross-section constructed and developed a technique for forming multi-point boundary conditions using struts, which are compression members. Based on the existing cases, a reasonable construction step for forming the material composite section of the entire structural system of the structure was derived, and a numerical analysis model for a specific part was constructed to analyze the behavior of the strut application. As a result of this study, the effect of reducing the sectional force of 7.40% in beam-column joint and 6.31% in the center of girder was derived, and the deflection, which is a measure of the serviceability of the structure, improved by 54.41% from the installation and dismantling of strut members at each construction stage.

대학급식소 작업시설과 환경의 미생물 오염도 분석 및 작업환경 실태조사 (Investigation of Microbial Contamination and Working Environment in University Foodservices)

  • 박순희;문혜경
    • 대한영양사협회학술지
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    • 제23권2호
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    • pp.180-191
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    • 2017
  • The purpose of this study was to identity the probability of cross-contamination from the environment. For this, we examined foodservices at 20 universities/colleges for microbiological analysis of their working facilities and environment as well as their preventive equipment against cross-contamination. Seventy percent of the 20 foodservices were found to maintain one unified working area, which suggests high probability of contamination of food/utensils/equipment in the cooking area by pre-preparation or dish washing. According to the microbiological analysis, the hygiene acceptance ratio of working facilities in the clean zone was 70%, which was higher than the average 45% hygiene acceptance ratio of working facilities in the contamination operating zone. There was a significant difference in the total plate count (P<0.001) and coliform count (P<0.01), which demonstrates that work tables in the clean zone were in a good state compared to those in the contamination operating zone. In the contamination operating zone, refrigerator shelves had a high probability of cross-contamination. Regarding the floor surface and airborne microbes, cooking areas which should be maintained as clean zones had higher cross-contamination probability than those in the contamination operating zone. So corrective actions such as cleaning and sanitizing, keeping dry floors, lowered temperature and humidity, shoe disinfecting facilities, and checking concentrations, are necessary to manage floor surfaces and airborne microbes in the cooking area.