We present new approach to analysis of velocity data of globular clusters. Maximum likelihood method is applied to get model parameters such as central potential, anisotropy radius, and total mass fractions in each mass class. This method can avoid problems in conventional binning method of chi-square. We utilize three velocity components, one from line of sight radial velocity and two from proper motion data. In our simplified scheme we adopt 3 mass-component model with unseen high mass stars, intermediate visible stars, and low mass dark remnants. Likelihood values are obtained for 124 stars in M13 for various model parameters. Our preferred model shows central potential of W o = 7 and anisotropy radius with 7 core radius. And it suggests non-negligible amount of unseen high mass stars and considerable amount of dark remnants in M13.

본 논문은 수식화의 특이성 때문애 구조 최적화 문제에 거의 사용되지 않고 있는 선형 goal programrrung을 대규모 비선형 구조 최적화에 용용하는 방법올 제시한다. 이 방법은 다기준 최적화의 도구로 사용 되는데 그 까닭은 goal programming 이 목적합수와 제한조건둥을 정의하는데 있어서 발생하는 난점 들올 제거해 주기 때문이다. 이 방병은 비선형 goal 최적화 문제톨의 해톨 얻기 위해서 유한요소해석， 선형 goal programming 기볍 ‘ 그리고 계속적인 선형화 기법을 이용한다. 즉， 대규모 비선형 구조 최적화 문제를 비선형 goal programming 형태로 전환시키는 일반적인 수식화 방법을 제시하고， 얻어진 비선형 goal 최적화 문제 를 풀기 위한 계속적인 선형화 방법에 대해서도 논의한다. 얼계도구로서 이 방법의 유효성올 논증하기 위하여 10‘ 25 및 200트러스의 사례를 가지고 용력채한조건들의 최소무게 구조 최적화 문제에 대한 해를 모색하며 이 쓸 다른 연구결과와 비교검토한다.

Denitrification activity of microbial communities in sand-gravel sediments and biofilms developing on a concrete riverbed of an urban small stream, Nogawa River, was measured monthly by laboratory incubations after the acetylene inhibition technique during une year from December 1987. The annual mean denitrification rate of the biofilm samples, 1.5 mgN m-2 h-1. was higtrer than the rate ut the sandgravel sediment samples. 0.8 mgN m-2 h-1. Contrary, ratios of the denitrified nitrogen to the total inorganic nitrogen fluxes was lower at the stretch where an attached microbial community developed un the concrete riverbed the stretch with sand-gravel riverbed. The longer residence times of water masses ut the site with a sand-gravel riverbed is responsible for the above relationship. Based on the average denitrifieation rates, if all the channel of Nogawa River were covered with concrete, the proportion of denitrified nitrogen to the input nitrogen should decrease to 1.3 %, whereas the ratio is 2.5% when the riverbed is composed of sands and gravel. The results suggest that the efficiency of nitrogen removal by benthic denitrification is strongly affected by the structure of a channel of the river.

Using the photographic imagery of the SO galaxy NGC 5102, the equivalent luminosity profile and the fractional integrated luminosity curve have been derived. Several photometric parameters of the galaxy, such as a total magnitude ( B T ), equivalent radius ( r ∗ e ), effective surface brightness ( μ ∗ e ), and concentration indices ( C 21 , C 32 ) were derived from the luminosity profiles. According to the decomposition method from the nonlinear least squares fitting, photometric parameters of the bulge ( μ e , r e ) and the exponential disk ( μ ( 0 ) , α − 1 ), and the bulge to total luminosity ratio (B/T) were obtained. The derived central disk surface brightness ( μ ( 0 ) = 22.06 ± 0.18 m a g / □ " ) and the evaluated B/T ratio (= 0.52) of the NGC 5102 are close to the mean values ( μ ( 0 ) = 21.65 ± 0.3 m a g / □ " , B/T=0.63) of the SO galaxies. Analysis showed that a lens-like hump is embedded in the equivalent luminosity profile of the NGC 5102.

We test an evolution of a giant void using an N-body simulation. We find the void expansion is faster than the rest part of the universe and the shape of an isolated aspherical void becomes more spherical as it evolves.

Korean economic growth in exports has been phenomenal in the past two decades. This paper deals with a series of export studies of small- and medium-sized manufacturing firms in Korea which look at export behavior and the conditions which influence export sales in these firms. Profiles of the firms are provided, in addition to discussions of the key influences on initiating exports, channels selection, profitability, and attitudes toward exporting.