The bumblebees, Bombus species are valuable natural resources being utilized for greenhouse pollination. Low level of genetic variation of Bombus species has been reported previously. In this study, we sequenced complete internal transcribed spacer 2 (ITS2) of the nuclear rDNA from 100 individuals of B. ardens collected from seven localities in Korean peninsula. The ITS2 sequence of B. ardens is longest, ranging in size from 1,940 bp-1,954 bp among known in insects, which ranges approximately from 241 bp-1,728 bp. The ITS2 sequences have ~51% of C+C content and contain each two 27 bp repeats, 20 bp repeats, 33 bp repeats, and 34 bp repeats at the beginning. Such repeats were not found in other insects. Uncorrected pairwise distance among 96 sequences that were obtained from 100 individuals revealed a maximum sequence divergence of 1.03%. Genetic diversity (π) of each population ranged from 0.007801 to 0.009627, and the lowest diversity was obtained from islet population of Ulleungdo, indicating possibly small, isolation of the population. Significant level of genetic distance was only found when Ulleungdo population was compared to two other mainland populations. Except for this, overall, a very high rate of per generation migration ratio (Nm=7.1-infinite) and a very low level of genetic fixation (FST=0-0.06546) were detected between pairs of localities. Analysis of hierarchical relationships among localities consistently revealed no statistically significant structure among populations. Taken these together, the B. ardens populations on the Korean peninsula are panmictic this is consistent with our understanding of the dispersal capability.

The bumblebee, Bombus ardens, is a valuable natural resource, and is most notably utilized for greenhouse pollination. In order to gain a greater understanding of the population genetic structure and the genetic diversity of this species, we sequenced a portion of the mitochondrial COI gene corresponding to the “DNA Barcode” region (658 bp) from 160 individuals collected over 15 Korean localities. Uncorrected pairwise distances among the eight haplotypes suggested low intraspecific genetic diversity, with a maximum sequence divergence of 0.3%. Such a low level of intraspecific genetic diversity was further reflected in local populations, particularly to islet populations, such as those of Youngheungdo, Jakyakdo, and Ulleugdo, which had zero genetic diversity. Geographically, one haplotype (BARBA01) was widespread and dominant, with a frequency of 90.6% (145 among 160 individuals). Other haplotypes were restricted to one to three localities and had low frequency. Overall, a very high rate of per generation female migration ratio (Nm= 4.6 to infinite) and a very low level of genetic fixation (FST= 0 to 0.099) were detected between pairs of localities, suggesting that the B. ardens population sonthe Korean peninsula are panmictic, which is consistent with our understanding of their dispersal capability.

Niobium powder was made from potassium heptafluoroniobite () as the raw material using sodium (Na) as a reducing agent based on the hunter process. The apparatus for the experiment was designed and built specifically for the present study. The niobium particle size greatly increased as the reduction temperature increased from to . The particle size was fairly uniform, varying from to depending on the reduction temperatures. The niobium powder morphology and particle size are very sensitive to a reaction temperature in the metallothermic reduction process. The yield of niobium powder increased from 55% to 80% with a increasing a reaction temperature.

본 연구는 남녀 대학생을 대상으로 동일색조 코디네이션과 1:2:3면적비 변화에 따른 스트라이프 넥타이의 감성이미지와 상호작용효과를 알아보고자 한다. 이들 단서로 사용된 56개 자극물은 4가지 색조합, 2가지 색조, 7가지 면적비로 구성되었고, 감성이미지는 26개의 형용사쌍에 대해 7단계로 평가되었다. 조사대상자는 경남, 서울, 부산, 대구 등지에 거주하는 대학생 1344명의 피험자로 하였으며, 그 연구결과는 다음과 같다. 동일색조 코디네이션과 1:2:3면적비 변화에 따른 스트라이프 넥타이의 감성이미지를 요인분석한 결과 매력성, 젊음 활동성, 현시성, 능력성, 온유성의 5가지 차원으로 도출되었다. 색조합과 색조는 감성이미지의 모든 요인에서 독립적인 영향을 나타내었다. 또한 색조는 면적비와 상호작용하여 현시성과 능력성 요인에서 두드러진 단서로 작용하였다. 성별과 면적비는 젊음 활동성 요인에서, 성별과 색조는 온유성 요인에서, 색조합과 색조는 현시성과 온유성 요인에서 상호작용효과를 나타내었다. 이러한 연구결과는 남성 코디네이션을 위한 효과적인 기초자료로 활용될 것이다.

본 연구는 와플구조의 구조적 거동에 파악하고자 한다. 와플슬래브의 두께, 주요 보의 깊이와 기둥의 크기를 변수로 하여 와플구조의 모드형상과 고유진동수를 파악하고자 하였다. 또한 쉘요소와 입체요소를 사용한 유한요소모델의 해석결과를 비교하였다. i)레벨2에서 주요 보의 깊이가 증가함에 따라, ii)레벨3에서 와플슬래브 두께가 감소함에 따라 모드진동수는 증가하였다. 3차원 모델과 2차원 모델의 모드형상은 유사한 형상을 보였다. 또한, 3차원 모델과 2차원 모델사이의 모드진동수는 25%에서 36%의 차이를 보였다.

Male adults of bean bug, Riptortus clavatus Thunberg (Heteroptera: Alydidae), release aggregation pheromone (AP) which consists of (E)-2-hexenyl (Z)-3-hexenoate (E2HZ3H), (E)-2-hexenyl (E)-2-hexenoate (E2HE2H), and tetradecyl isobutyrate (TI). Variation in the pheromonal secretion were checked by the factors of age, mating status, seasons, body weight and time in a day. There were no significant differences in the amounts of AP secretion by mating, body weight, and time in a day. Higher amount of AP was detected from older males than younger ones. The amount of AP detected was higher in the males collected from April to September than in those collected during October. No AP was detected in the males of November and December. These phenomena in the AP secretion were discussed in relation to food exploitation and reproductive diapause of the bean bug.

On cold start operation of a gasoline engine, a catalyst shows poor performance before it reaches activation temperature. Therefore, fast warmup of the catalyst is very crucial to reduce harmful emissions. In this study, an appropriate control strategy is investigated to increase exhaust gas temperature through changes of exhaust valve timing. An advance of exhaust valve timing decreases residual gas in cylinders due to decrease of valve overlap period. A control strategy of proper valve timing is suggested in order to achieve fast light-off of the catalyst and stable operation of the engine in a cold start and idle operation.

Purpose : We have investigated the vanatwn between ocular components and re(ractive error v.~lh various age groups between 20 to 69 years old. Methods : Refractive error and ocular components were measured in 100 adults (200 eyes) v.~th healthy eyes. Spherical equivalenl. corneal power and mean corneal radius were measured using a Canon RK-Fl autorefractor. Anterior chamber depth and axial length measurements were made using IOL Master. AUCR ratio was calculated by dividing axial length measurements by mean corneal radius. Power vector analysis was used to analyze the refractive error which is expressed with three vectors : M, Jo. J 15· Results : Measured Spherical equivalent values were -1.51±2.480(males -1.33± 2.070, females -1.63±2.670). and showed significant age groups dependence. Measured AUCR ratio values were 3.15±0.15(males 3.16±0.12. females 3.15±0.17). and showed significant age groups dependence. Prevalence of spherical equivalent were as follows : myopesOlleyes. 55.5%). emmetropes(49eyes. 24.5%). hyperopes (40eyes. 20%), and astigmatic eyes(89eyes, 44.5%). As increasing the age from 20s to 60s, M components of power vector analysis showed the change myopia to hyperopia(from -3.44±2.460 to 0.88±1.270). Jo components of power vector analysis changed with-the-rule(WfR) to against-the-rule(ATR)(0.41±0.67D for 20s and -0.01± 0.350 for 40s). J4s components of power vector analysis were -0.67±0.140 for 20s and 0.09±0.270 for 50s. ln J.,s components analysis. the cylinder axis observed near 135 degree for 20s and 45 degree for 50s. Linear regression analysis showed the strong negative correlation between axial length and spherical equivalent(r = -0. 73. p < 0.0001). The correlation between AUCR ratio and spherical equivalent showed the most strong negative dependence(r = -0.82, p < 0.0001). Conclusion : Prevalence of myopia showed 55.5%0lleyes) in 200 eyes. Refractive error showed the change from myopia to hyperopia and total astigmatism showed the change from with-the-rule to against-the-rule with increasing ages. Analysis of biometric data showed that AUCR ratio has the highest negative correlation with spherical equivalent.

This paper examines variation found in the usage of English relatives by Korean users and learners of English. Two types of data are analyzed using Varbrul analysis: academic articles written by English major professors and compositions by college students majoring and minoring in English. The results of analyses can be summarized as follows: 1) Korean users and learners of English adopt wh-variants more frequently than Americans for use but less commonly than Britons, 2) Advanced English users generally show the usage pattern of English relatives similar to that of native English speakers conditioned by very similar linguistic constraints, 3) Korean English learners with intermediate proficiency level revealed somewhat different patterns of English relative use from those of native English speakers and advanced Korean English users, 4) Prescriptive grammar taught in middle and high schools is analyzed as exerting significant influence on the pattern of English relative use by Korean users and learners of English. (157)

본 조사에서는 양식업 및 수산업에 있어서 중요한 부분을 차지하고 있는 가막만을 대상으로 수질환경 변화에 대한 이매패류의 군집구조 및 연간변동을 파악하고 물리적 화학적 환경이 이매패류 군집에 미치는 영향을 분석하고자 하였다. 가막만 해역의 12개 정점을 설정하고 2001년부터 2006년까지 4월, 7월, 9월, 11월 계절별로 조사한 결과 이매패류 총 28종이 출현하였으며, 평균 서식밀도는 226.72±196.20 ind. m-2의 변동범

확정론적 최적설계에서는 설계변수의 변동이나 불확실성 등을 최적화 과정에서 고려하지 않는다. 신뢰성 최적설계는 설계변수의 임의성을 체계적인 확률 및 통계이론을 적용하여 생산품의 안정성을 보다 정밀하고 합리적으로 다룬다. 본 논문에서 설계변수를 확률변수로 취급하여 실제 제작시의 제작오차를 고려한 표준편차를 주었으며, 설계변수의 평균에 대한 표준편차를 기존의 고정된 값을 사용하지 앉고 평균과 표준편차의 관계가 오목함수로 나타나도록 하였다 즉, 설계변수의 평균이 달라짐에 따라 표준편차도 변동계수만큼 변하도록 하였다. 신뢰성해석은 불변 2차 모멘트 방법을 이용하고 신뢰성을 구하는 방법은 신뢰도 지수 접근방법의 개선된 일계 2차 모멘트 방법을 이용하여 신뢰성을 구하였다. 두 가지 예제를 통해 확정론적 최적설계, 신뢰성 최적설계와 표준편차의 변동을 고려한 신뢰성 최적설계의 값을 비교하였다.

Consistent individual difference in a behavior is recognized as an important evolutionary force in niche variation and may be a personality trait, an inherent property of the individual. To understand whether aggressiveness is a personality trait, independent of resource holding potential (RHP) and resource value in animal aggression assumed by game theory models, I determined individual variation in aggressiveness by measuringboth positive phonotactic and acoustic responses to the broadcast stimulus repeatedly over the three-week period in males of Gryllus rubens. Factors tested included amplitude levels of the broadcast stimulus, body size, wing dimorphism, and age. The analyses of the generalized linear mixed models revealed that RHP factors such as age, wing dimorphism, and body size, were not significant for both positive phonotactic and acoustic responses. However, there seemed to be more aggressive responses to higher levels of amplitudes. The significant variance-covariance structures of the models indicated that some individuals consistently aggressive or nonagressive during the experimental periods. Because potential factors for resource values were controlled, and because potential RHP factors would not explain variation in aggressive responses, I concluded that aggressiveness is a personality trait that is not characterized by factors that I tested.