• Bulletin of the Korean Mathematical Society
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• v.61 no.2
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• pp.557-584
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• 2024

An almost complex torus manifold is a 2n-dimensional compact connected almost complex manifold equipped with an effective action of a real n-dimensional torus Tⁿ ≃ (S¹)ⁿ that has fixed points. For an almost complex torus manifold, there is a labeled directed graph which contains information on weights at the fixed points and isotropy spheres. Let M be a 6-dimensional almost complex torus manifold with Euler number 6. We show that two types of graphs occur for M, and for each type of graph we construct such a manifold M, proving the existence. Using the graphs, we determine the Chern numbers and the Hirzebruch χ_y-genus of M.

• Korean Journal of Community Nutrition
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• v.8 no.2
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• pp.220-230
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• 2003

The purpose of this study was to investigate consumer preferred formats of nutrition labels: the type of nutritional information provided on the labels. A survey was conducted on 222 housewives between the age of 20 and 65 in Daejeon city in 1998, using an interview questionnaire showing illustrated nutritional label formats. Among twelve nutrients and caloric values listed on the nutrition labels, the housewives ranked their interest in the items in the following order of calorie (58.56%), calcium (56.76%), cholesterol (54.05%), protein (39.19%) and vitamin C (36.04%). The majority of the subjects (69.37%) checked labels when they bought milk or dairy products, whereas only 8.11% looked at labels when they bought Ramyon or noodles. Most of the subjects (90.99%) preferred products with labels with nutritional information as compared with products without labels. this was especially so true of the younger individuals and of pc-ople who checked food labels more frequently. The subjects preferred labeling which described the nutrient content per Package (55.41%), sewing size (32.88%) and food weight of 1009 (11.71%) as a standard nit. Generally, they prefer-red a simplified list to a detailed list of the number of nutrients, a figure graph to bar graph in nutrition claim, vertical bar graph to horizontal bar graph showing the nutritional content of foods and a web-type graphic format to a radiation-format when describing the item's percentage of the Korean RDA's nutrient content. The subjects who checked labels frequently especially preferred detailed list, while housewives with job or with unhealthy family members preferred a simplified list and graphic, rather than a numerical display. From this result, it is suggested that providing consumers with more nutrients information in a more easily understood graphic format would encourage the consumers to check nutritional labels. Therefore this should be considered when developing the regulations far nutrition labeling or when educating the Public about nutrition. (Korean J Community Nutrition 8(2) : 220∼230, 2003)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.773-777
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• 2002

In this study, we analyzed the LPG and LNG sensitivity measurement and voltage variation using catalytic type gas sensor characteristics in catalytic combustion type gas detecter sensors. gas detector shall operate as intended when exposed for 24 hours to air having a relative humidity of 0~85 percent at a temperature of $20[{\mu}m]$ and humidity of 45 percent at a temperature of $-10{\sim}40[^{\circ}C]$ the gas detecter sensors are to be subjected to operation for 210 days in an area that has been detemined to be equivalent to a typical residential atmosphere with an air velocity of 50 [cm/sec]. The source of energy for a gas detector sensors employing a supplementary basic circuit is energized from a separate source of supply direct applied voltage 2.1[V], 2.2[V], 2.3[V]. As a result, it was confirmed that the relative humidity and temperature by regression each analysis, compared to the LPG characteristic graph and methane characteristics graph by a relative humidity of 0 ~ 85 [%] at a temperature range of $-10{\sim}40[^{\circ}C]$ show a similar linear pattern on the whore.

• Journal of Power System Engineering
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• v.14 no.3
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• pp.77-82
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• 2010

In general, the control valves are essential components in hydraulic systems. Structural changes within the valves remain a challenge because many parameters of valve tend to interact in terms of static and dynamic performance. Therefore, the valve characteristics is applied directly to the stability of hydraulic system. Inner structure of the valve which is used mainly in the industries is made up poppet type and spool type. This paper made a description of the method for numerical analysis and modeling of the valve with a built-in moving part of four-type. Based on the physical parameters of the valves, a numerical model of objected valve is developed using the bond graph method. It is to verified the results that the moving part of four-type has an effect on pressure and flow characteristics. Also, It is analyzed the results which has an effect on response characteristic by angular of poppet valve face and inertia variation of the valve with a built-in moving part. In the results, it is confirmed that the rising and settling time vary with the shape of moving part in valve.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.335-341
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• 2017

This paper proposes an image-processing algorithm for inspecting double-cut defects in the motor shaft manufacturing process. The algorithm consists of extracting the outline using the brightness of the image, obtaining a binarized boundary graph using the extracted outline, and determining the defects from the graph. Defects in which two cut surfaces are separated are considered type 1 defects, and those in which two cut surfaces are connected are defined as type 2 defects. In an actual manufacturing process, 112 good samples and 44 defective samples (34 type 1 defects and 10 type 2 defects) were collected and used to verify the algorithm. The samples were judged with 100% accuracy for both type 1 and type 2 defects. The algorithm will be used in the field after securing reliability for various samples.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10b
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• pp.289-291
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• 1998

최근 멀티미디어 자료(Multimedia Data)들을 이용한 멀티미디어 상연물(Multimedia Presentation)의 제작에 많은 관심이 쏟아지고 있다. 한편, 멀티미디어 상연물들의 효과적인 사용을 위해서는 멀티미디어 상연물과 데이터베이스 시스템(Database System)의 통합(Integration)이 필요하며 이에 그래프 타입(Graph Type)을 이용하여 표현되고 있는 멀티미디어 상연물의 검색을 위한 검색 언어(Query Language)의 필요성이 대두되고 있다. 검색언어는 멀티미디어 자료들의 물리적 특징과 내용(Content), 상연물을 표현하는 데이터 타입(Data Type)을 표현할 수 있어야 한다. 또한 검색 언어는 사용자(end-user)가 손쉽게 사용할 수 있어야 한다. 이에 앞서 언급된 멀티미디어 상연물 검색 언어가 갖추어야할 요소들을 가지고 있으며 또한 사용자가 편리(user-friendly)하게 사용하는 visual language의 formal basis가 되는 calculus에 바탕을 둔 검색 언어인 GCaluculus/S를 소개한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.267-270
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• 2001

A lot of efforts have been made to analyze the performance of the vehicle equipped with automatic transmission through simulation. It might be necessary to understand the different types of transmissions, i.e., different power flows, for different models. If there is a module that can be applied to different types of automatic transmission, it could be helpful to transmission-related engineers. This study has started up from this idea. The common bond graph has been obtained from several types of the automatic transmission. The overall generalized equations and kinematic constraint equations have been derived using virtual power sources on common bond graph. They are used to derive state equations and constraints. These equations have been applied as an application to the vehicle equipped with two simple planetary gear set type of Ravigneaux gear type automatic transmission. The state equation, kinematic constraints, and dynamic constraints have been derived in every gear and shift operation using overall generalized equations and kinematic constraint equations. Simulations for constraint speed running, standing-start running, rolling-start running, and LA-4 mode have been conducted to analyze the performance of the vehicle powertrain using GVPS(Generalized Vehicle Powertrain Simulation) program wit pull down menus.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.4
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• pp.591-600
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• 1998

The scheduling of parallel computing systems consists of two procedures, the assignment of tasks to each available processor and the ordering of tasks in each processor. The assignment procedure is same with a clustering. The clustering is classified into linear or nonlinear according to the precedence relationship of the tasks in each cluster. The parallel computing system can be modeled with a Directed Acyclic Graph(DAG). By the granularity theory, DAG is categorized into Coarse Grain Type(CDAG) and Fine Grain Type(FDAG). We suggest the linear clustering method for the scheduling of CDAG using the genetic algorithm. The method utilizes a properly that the optimal schedule of a CDAG is one of linear clustering. We present the computational comparisons between the suggested method for CDAG and an existing method for the general DAG including CDAG and FDAG.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.2
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• pp.93-99
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• 2001

A new type geometric and mathematical network reduction model is introduced. Large-scale network is analyzed with analytic approach. The graph has many nodes, branches and loops. Circuit equation are obtained from these elements and connection rule. In this paper, the analytic relation between voltage source has a mutual different graphic property. Node-reduction procedure is achieved with this circuit property. Consequently voltage source value is included into the adjacent node-analyzing equation. A resultant model equations are reduced as much as voltage source number. Matrix rank is (n-1-k), where n, k is node and voltage source number. The reduction procedure is described and verified with geometric principle and circuit theory. Matrix type circuit equation can be composed with this technique. The last results shall be calculated by using computer.

• Kyungpook Mathematical Journal
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• v.59 no.3
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• pp.363-375
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• 2019

Let G = (V, E) be a simple graph with p vertices and q edges. A subset S of V (G) is called a strong (weak) efficient dominating set of G if for every $v{\in}V(G)$ we have ${\mid}N_s[v]{\cap}S{\mid}=1$ (resp. ${\mid}N_w[v]{\cap}S{\mid}=1$), where $N_s(v)=\{u{\in}V(G):uv{\in}E(G),\;deg(u){\geq}deg(v)\}$. The minimum cardinality of a strong (weak) efficient dominating set of G is called the strong (weak) efficient domination number of G and is denoted by ${\gamma}_{se}(G)$ (${\gamma}_{we}(G)$). A graph G is strong efficient if there exists a strong efficient dominating set of G. In this paper, some cycle and star related Nordhaus-Gaddum type relations on strong efficient dominating sets and the number of strong efficient dominating sets are studied.