• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.579-585
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• 2019

Increasing the detection probability of underwater targets necessitates securing the towing stability of the active towed SONAR. In this paper, to confirm the effects of tail wing fin on towing attitude and towing stability, two scale model experiments and one sea trials were conducted and the results were analyzed. The scale model tests measured the towing behavior of each of the tail fin shapes according to towing speed in a towing tank. The shape of the tail fin used in the scale model test was tested with an I-type tail fine and four Y-type tail fins, totaling five tail fins of the two kinds. The first scale model test confirmed that the Y-type tail fin was superior to the I-type tail fin in towing attitude and towing stability. The second scale model test confirmed the characteristics of the vertical tail fin height increase and the lower horizontal tail fin inclination angle application shape based on the Y-type tail fin. The shape of the application of the lower horizontal tail fin inclination angle showed the best performance. In order to verify the results of the scale model test, a full size model was constructed, sea trials were performed, and the towing attitude was measured. The results were similar to those of the scale model test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.267-274
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• 2021

Among several methods for determining the allowable lateral resistances of piles, the subgrade reaction method and ultimate lateral resistance method are generally used. To determine the effects of the soil conditions, pile head restraint conditions, and pile lengths on determining the allowable lateral resistances of piles, computations of the allowable lateral resistances of piles using the two methods were executed, and the computation results were compared. For piles in soft cohesive soil, the pile design is governed by the allowable lateral resistance of a pile from subgrade soil reaction method regardless of the pile head restraints conditions and pile lengths. The allowable lateral resistance of a pile from the ultimate lateral resistance governs the design as the undrained shear strength increases. Except for the case of a short pile, which is installed in loose granular soil, the allowable lateral resistance of a pile from ultimate lateral resistance governs the design of laterally loaded piles. According to this study, computation of the ultimate lateral resistance of a pile is needed, even though some opinions suggest that the design of a laterally loaded pile is satisfied only by the subgrade reaction method. The pile width barely influences the coefficient of horizontal subgrade reaction. Realistically, the effect of the pile width can be disregarded in the condition of common pile widths of 20~90cm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.621-626
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• 2021

In this study, data on the study site for apartment construction was acquired, and the quantity of construction waste was calculated using a drone and mobile 3D laser scanner. The accuracy of the drone was 0.034 to 0.064m in the horizontal and vertical directions, respectively, and the mobile 3D Laser Scanner showed an accuracy of 0.018 to 0.049m in the horizontal direction, respectively. These results suggest that it is possible to construct spatial information using a drone and mobile 3D laser scanner with a value within the allowable accuracy of 1:1,000 digital terrain. The volume of construction waste calculated using the mobile 3D laser scanner data was 70,797㎥. It was possible to calculate the volume on the side of the building or some facilities that appeared as shaded areas in the drone outcomes. In addition, modeling was performed for view analysis of the apartments scheduled to be constructed and the terrain-based modeling results of the surrounding buildings. In the future, data construction and accuracy evaluation using mobile 3D laser scanners will be conducted. In addition, additional research comparing existing methods and work processes will be carried out, and the efficiency of mobile 3D laser scanners in the field of spatial information construction can be presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.530-536
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• 2021

This paper presents the performance measurement results of a hybrid sheet with both shielding and heat dissipation functions developed by laminating copper mesh sheets and natural graphite sheets, which are used widely as electromagnetic shielding and heat-dissipating materials in electronic devices, without a pressure-sensitive adhesive (PSA). The results were compared by measuring the vertical and horizontal thermal conductivity with two other products to confirm the heat dissipation performance. A radiation emission test confirmed the electromagnetic shielding performance using a 3m electromagnetic anechoic chamber according to the CISPR 11 standard. In the case of vertical thermal conductivity, the proposed hybrid sheet was approximately 8.63 times higher than that of an aluminum sheet with heat dissipation coating and 18.7 times higher than that of a copper sheet laminated with artificial graphite with PSA. The proposed hybrid sheet was approximately 0.64 times that of the sheet, and approximately 1.76 times that of the heat-dissipated aluminum sheet in case of horizontal thermal conductivity. Measurements after applying each sheet in the same heat source revealed the proposed hybrid sheet to have the best heat dissipation performance. The radiation emission test showed that significantly radiation noise had been removed.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.4
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• pp.46-56
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• 2004

As economic cooperation and exchanges between North and South Korea have been glowing much more than before, the demand for geographic information on North Korea is recently increasing. In fact, there is no specific method to be provided with geographic information on North Korea. In this regard, the study searched a method to collect geographic information on North Korea by using the high spatial resolution satellite image. In order to produce its best result, the study collected the geographic information on the case study area and ensured the location accuracy. This study produced total 52 items of geographic information on North Korea. Horizontal and vertical errors of stereo image, which are 4.6m and 0.9m respectively, showed high accuracy. In addition, even though the horizontal error of single image is 9m, which is bigger than that of stereo image, there is no doubt that it can be used as basic data for North Korean studies and related projects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5148-5154
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• 2012

The purpose of this study was to analyze the kinematic characteristics of the thrower's center of mass (COM) and the shot that her performance hits record high for the 29th National Athletic Competition. Two S-VHS video cameras were used to visualize. The Direct Linear Transformation technique was employed to paint a clear picture in the three dimensional coordination. Kwon3D was used to analyze the data. The results showed that release velocity and height were 13.73 m/s and 198.6 cm(119% by height ratio), respectively, which is considered as peak performance comparing an extensive review of previous literature on the shot put. Release angle was $34^{\circ}$, which is lower than the previous studies. The path of thrower's center of mass is needed to travel in a release direction during the flight phase. The vertical movement of the thrower's center of mass during the driving should be controlled. At release, the perfact timing is required without vertical and horizontal movements of the thrower's center of mass.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3599-3609
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• 2010

Recently, the construction of coastal structures and high-rise structures against the horizontal and uplift forces increases with the developing the coastal developments. Especially the application of belled tension pile as foundation type to effectively resist uplift force is increasing in coastal structures. However, research on pullout resistance of belled tension pile has been limited and not yet been fully performed. Therefore, the pullout load tests of belled tension piles in four overseas sites were performed, then the bearing capacity, characteristics on load-displacement of piles and load distribution considering skin friction were investigated in this paper. In addition, the limit pullout bearing capacity calculated by the three-dimensional finite element analysis and theoretical methods were compared with values of in-situ test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4126-4130
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• 2012

In this paper, we proposed planar spiral inductors based on AC coupling for high-frequency wireless signal transmission. Design and characteristics of various structures of the inductor were analyzed. Capacitance between the inductors can be reduced by positioning two thin-film inductors in parallel. So two structures were proposed. First structure is inter-diagonal structure. This structure was made not to overlap the wire part of the paralleled two inductors. Second structure is On-chip type structure that the two thin-film inductors were in parallel but located on diagonal line not to face each other. The resonance in this structure was reduced from twice to once by increasing horizontal distance between the two thin-film inductors, because the capacitance effect between the two thin-film inductors decreases when the distance between the two inductors increases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5764-5769
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• 2012

Business relationships can be divided in vertical and horizontal relationships. Vertical relations, such as the relation to suppliers and contractors, are of great importance and often determine a firms success. In general, many scholars produced numerous models of business relationships covering with a wide array of variables. However, models with a focus on vertical relationship did not receive much attention. This paper deals with problems related to vertical relationships and a the business model paying special attention to vertical relationships is developed. Vertical relationships span over a wide range of industries, including industrial electronics and automotive firms. In Chapter 2, the theoretical approach needed to develop a process model to examine the vertical relationships is developed. Chapter 3 features core findings about business relationships. Chapter 4 deals with vertical relationships as developed between the core business process model. Finally, Chapter 5 of the study covers limitations and future research directions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.39-45
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• 2009

The CRT(Cathode Ray Tube) displays have been substituted for FPDs(Flat Panel Displays) such as LCD(Liquid Crystal Display) and PDP(Plasma Display Panel) because they have a convex surface, large volume and heavy weight. The productivity of FPDs is greatly dependent on the area of thin glass panel with $0.6{\sim}0.8mm$ thickness because FPDs are manufactured by cutting a large-scaled thin glass panel with patterns to the required product dimensions. So FPD's industries are trying to increase the area of thin glass Panel. Through FEM(Finite Element Method) analysis and fluid analysis, we developed an non-contact and air-floating conveyor system which consists of transport-module, distributor, horizontal/vertical changer and controller for the 7th generation glass panel (2,200mm in width, 1,870mm in length and 0.7mm in thickness). The design technology developed in this study can be effectively applied to a conveyor system for a larger-scaled thin glass panel.