• The Korean Journal of Cytopathology
• /
• v.1 no.1
• /
• pp.36-42
• /
• 1990

The fluoroscopy-guided fine needle aspiration biopsy has been gaining widespread acceptance as a rapid and effective method to make a pre-operative diagnosis of mediastinal tumors including thymoma, malignant lymphoma, and metastatic carcinoma. Although thymoma is a most common tumor of the superior mediastinum, most cytopathologists are not experted in cytologic diagnosis of this tumor because of limited experience. In order to define the diagnostic cytologic features of thymoma, we have retrospectively reviewed imprinting smears and corresponding tissue sections from four cases of this tumor. All cases revealed an apparent biphasic pattern of epithelial cell clusters and lymphocytes with occasional branching capillary fronds extending from three dimensional epithelial cell clusters. Epithelial cell clusters predominated in one case and lymphocytes in two cases. Mixed epithelial cell and lymphocyte type represented in one of four cases. In the lymphocyte predominant type, the presence of epithelial cell clusters and small mature lymphocytes are helpful features to differentiate from a malignant lymphoma.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.484-487
• /
• 2004

Symmetric directional couplers are widely used in interferometers, switches, and various signal processing devices. Recently, several optical couplers using multimode fibers were reported, but these suffer from inefficient coupling of light into a branching fiber and/or low directivity. This paper presents the measurement and analysis of loss in the connection of optical fibers via the optical directional couplers. The functionality of the device is based on the principle that is symmetrical, the power in excited mode can be unambiguously directed into one of the output channel by varying and of its parameters. In this experiment, we measure the power of loss in the optical directional coupler at various radius of curvature. Before the measurement of loss in x-coupler, we polish the contact of the fiber surface in order that light can penetrate through another port. The results show that, when the radius of curvature is increased, the loss power is decreased and also approaches of the straight line case.

• Molecules and Cells
• /
• v.23 no.1
• /
• pp.64-71
• /
• 2007

To investigate the phylogeny of Patellogastropoda, the complete 18S rDNA sequences of nine patellogastropod limpets Cymbula canescens (Gmelin, 1791), Helcion dunkeri (Krauss, 1848), Patella rustica Linnaeus, 1758, Cellana toreuma (Reeve, 1855), Cellana nigrolineata (Reeve, 1854), Nacella magellanica Gmelin, 1791, Nipponacmea concinna (Lischke, 1870), Niveotectura pallida (Gould, 1859), and Lottia dorsuosa Gould, 1859 were determined. These sequences were then analyzed along with the published 18S rDNA sequences of 35 gastropods, one bivalve, and one chiton species. Phylogenetic trees were constructed by maximum parsimony, maximum likelihood, and Bayesian inference. The results of our 18S rDNA sequence analysis strongly support the monophyly of Patellogastropoda and the existence of three subgroups. Of these, two subgroups, the Patelloidea and Acmaeoidea, are closely related, with branching patterns that can be summarized as [(Cymbula + Helcion) + Patella] and [(Nipponacmea + Lottia) + Niveotectura]. The remaining subgroup, Nacelloidea, emerges as basal and paraphyletic, while its genus Cellana is monophyletic. Our analysis also indicates that the Patellogastropoda have a sister relationship with the order Cocculiniformia within the Gastropoda.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.13 no.2
• /
• pp.9-17
• /
• 1988

This vehicle scheduling problem with multiple depots and multiple vehicle types (VMM) is to determine the optimal vehicle routes to minimize the total travel costs. The object of this paper is to develope an exact algorithm for the VMM. In this paper the VMM is transformed into a mathematical model of the vehicle problem with multiple depots. Then an efficient branch and bound algorithm is developed to obtain an exact solution for this model. In order to enhance the efficiency, this algorithm emphasizes the follows; First, a heuristic algorithm is developed to get a good initial upper bound. Second, an primal-dual approach is used to solve subproblems which are called the quasi-assignment problem, formed by branching strategy is presented to reduce the number of the candidate subproblems.

• Journal of Korean Institute of Industrial Engineers
• /
• v.12 no.1
• /
• pp.73-80
• /
• 1986

This paper deals with the problem of the optimal location of warehouses in the two stage distribution system, i.e., the distribution system where the product is transported from plants to customer areas via warehouses. The Problem is formulated with a zero-one mixed integer programming and an efficient branch and bound algorithm is then used to solve the problem. In order to obtain the solution of this problem, this paper shows the procedure of conversion of two stage distribution system into one stage distribution system. An improved method of solving the linear programming at the nodes and branching decision rule is also showed by this study.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.12 no.1
• /
• pp.34-44
• /
• 1987

The general vehicle routing problem has been studied by many researchers such as Christofides, et al. and Laporte, et al., but only limited effort has been devoted to developing the optimal algorithms. The purpose of this paper is to develop a branch and bound algorithm which determines the optimal vechicle routes and the optimal number of vehicles concurrenetly for the asymmetrical vehicle routing problem. In order to enhance the efficiency, this algorithm emphasizes the followings ; First, an efficient primal-dual approach is developed to solve subproblems which are called the specialized transportation problem, formed by relaxing the illegal subtour constraints from the vehicle routing problem, second, an improved branching scheme is developed to reduce the number of candidate subproblems by adequate utilization of vehicle capacity restrictions.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1155-1162
• /
• 2004

This research proposes a new risk analysis method in order to guarantee successful performance of construction projects. The proposed risk analysis methods consists of four phases. First step, AHP model can help contractors decide whether or not they bid for a project by analysing risks involved in the project. Second step, the influence diagraming, decision tree and Monte Carlo simulation are used as tools to analyze and evaluate project risks quantitatively. Third step, Monte Carlo simulation is used to assess risk for groups of activities with probabilistic branching and calendars. Finally, Fuzzy theory suggests a risk management method for construction projects, which is using subjective knowledge of an expert and linguistic value, to analyze and quantify risk. The result of study is expected to improve the accuracy of risk analysis because three factors, such as probability, impact and exposure, for estimating membership function are introduced to quantify each risk factor. Consequently, it will help contractors identify risk elements in their projects and quantify the impact of risk on project time and cost.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.19 no.1
• /
• pp.153-168
• /
• 1994

This paper is concerned with the development of tree-search algorithm for the exact solution to the vehicle problem (VRP), where set of vehicles of known capacity based at depot, have to be routed in order to supply customers with known requirements. When is required is to design routes, so that the total cost (i. e. total route length or time duration, ect.) is minimized. For obtianing the exact solution, the most important factors are the value of bound and branching strategy. Using the bound based on with bound ascent procedures from subgradient and state-space ascents, the incorporation of bounds into tree search algorithm to solve the problem is shown. Computational results of the corresponding algorithm show that VRPs with up to 40 customers can be solved optimally with this algorithm.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.26 no.1
• /
• pp.31-52
• /
• 2024

Considering the significant relationship between a tree's branch structure and physiology, understanding the detailed branch structure is crucial for fields such as species classification, and 3D tree modelling. Recently, terrestrial laser scanning (TLS) and quantitative structure model (QSM) have enhanced the understanding of branch structures by capturing the radius, length, and branching angle of branches. Previous studies examining branch structure with TL S and QSM often relied on mean or median of branch structure parameters, such as the radius ratio and length ratio in parent-child relationships, as representative values. Additionally, these studies have typically focused on the relationship between trunk and the first order branches. This study aims to explore the distribution of branch structure parameters up to the third order in Aesculus hippocastanum, Ginkgo biloba, and Prunus yedoensis. The gamma distribution best represented the distributions of branch structure parameters, as evidenced by the average of Kolmogorov-Smirnov statistics (radius = 0.048; length = 0.061; angle = 0.050). Comparisons of the mode, mean, and median were conducted to determine the most representative measure indicating the central tendency of branch structure parameters. The estimated distributions showed differences between the mode and mean (average of normalized differences for radius ratio = 11.2%; length ratio = 17.0%; branching angle = 8.2%), and between the mode and median (radius ratio = 7.5%; length ratio = 11.5%; branching angle = 5.5%). Comparisons of the estimated distributions across branch orders and species were conducted, showing variations across branch orders and species. This study suggests that examining the estimated distribution of the branch structure parameter offers a more detailed description of branch structure, capturing the central tendencies of branch structure parameters. We also emphasize the importance of examining higher branch orders to gain a comprehensive understanding of branch structure, highlighting the differences across branch orders.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.18 no.3
• /
• pp.271-277
• /
• 1985

As the fundamental studies for the population of Myagropsis myagroides, the effect of plant hormones on the regeneration for the primary, secondary lateral and receptacle segments were investigated. At high concentration($10^{-3}M\;and\;10^{-4}M$) of plant hormones inhibits from regenerating and lower concentrations advance the regeneration. The most effective concentrations of hormones on the primary lateral segments are $10^{-6}M$ of kinetine, IAA, NAA and $10^{-5}M$ of 2, 4-D in order, meanwhile in the secondary lateral segment $10^{-6}M$ of NAA, $10^{-8}M$ of kinetine, $10^{-7}M$ of IAA, and $10^{-5}M$ of 2, 4-D in order. The net regeneration rates of primary and secondary lateral segments which are measures by the wet weight are $124.1\%\;and\;228.9\%$, respectively. The influence of apical dominanace on the primary lateral segments decreases, on the other hand, increases in the secondary lateral segments because of the distance from the apex, Especially, the secondary lateral segments treated with below $10^{-5}M$ plant hormone are matures with receptacle of small branching by the regenerated branching.