• Journal of the Korean Institute of Rural Architecture
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• v.18 no.2
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• pp.55-62
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• 2016

The goal of this study is to recreate the identification of landscape image through the Agricultural Architecture in rural area. Most of them are not kept with houses in traditional village and the other structures in garden area of Korea, because they are located in the isolated field or placed near along the local street, are designed as a very heavily designed building, and are covered by different materials and color against village architecture. I researched cattle barns in both Korea and Germany of what they have had images in a distance-view points of local area, so that I might find a suitable image of Barn Architecture with topography of rural areas. I surveyed rural agricultural buildings with different point of views on landscape structure, architectural form and materials, and conditions animal welfare. There are three results from this paper as follows: First, the placement of animal barn in garden area is isolated to village so that it may keep a clean environment of village, which it makes non appropriate to land using and village view. Second, the architectural form makes a different image to the village building, because it has an oversize against houses in village or has no rhythm and dividing form of simple gable barm. Third, the barn architecture is better to consider of eco-friendly materials with animal welfare concept design, when it starts to design the barn in the field.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.128-133
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• 2011

In this study, the steel material for shipbuilding(LR-A class) was used, and FCAW was taken advantage of 3G attitude and they are welded by different welding ways. As a result of analyzing wave with welding monitoring system, the stable values are obtained which are the first floor(electronic current 164~182 A, voltage 24 V), the second floor(electronic current 174~190 A, voltage 22~25 V), the third floor(electronic current 158~188 A, voltage 22~25 V), and fourth floor(electronic current 172~184 A, voltage 22~25 V), at this time, the stable wave standard deviation and changing coefficient could be obtained. When the welding testing through nondestructive inspection was analyzed know defect of welding, there was no defect of welding in A, D, E, but some porosities in B, and slag conclusion near the surface in C, because the length of arc was not accurate, and the electronic current and voltage was not stable. After observing the change of heat affect zone through micro testing, each organization of floor formed as Grain Refinement, so welding part was fine, the distance of heat affect zone is getting wider up to change the values of the electronic current and voltage. As a result of degree of hardness testing, the hardness orders were the heat affect zone(HAZ), Welding Zone(WZ), and Base Metal(BM). When the distribution of degree of hardness is observed. B is the highest degree of hardness The reason why heat effect zone is higher than welding zone and base metal, welding zone is boiled over melting point($1539^{\circ}C$) and it starts to melt after the result of analysis through metal microscope, so we can know that delicate tissue is created at the welding zone. Therefore, in order to get the optimal conditions of the welding, the proper current of the welding and voltage is needed. Furthermore the precise work of welding is required.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.521-522
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• 2006

In this paper, hybrid air-water discharges were used to develop an optimal condition for providing a high level of water decomposition for hydrogen yield. Electrical and optical phenomena accompanying the discharges were investigated along with feeding gases, flow rates, and point-to-plane electrode gap distance. The primary focus of this experiment was put on the optical emission of the near UV range, with the energy threshold sufficient for water dissociation and excitation. The $OH(A^{2+},'=0\;X^2,"=0$) band's optical emission intensity indicated the presence of plasma chemical reactions involving hydrogen formation. In the gaseous atmosphere saturated with water vapor the OH(A-X) band intensity was relatively high compared to the liquid and transient phases although the optical emission strongly depended on the flow rate and type of feeding gas. In the gaseous phase discharge phenomenon for Ar carrier gas transformed into a gliding arc via the flow rate growth. OH(A-X) band's intensity increased according to the flow rate or residence time of He feeding gas. Reciprocal tendency was acquired for $N_2$ and Ar carrier gases. The peak value of OH(A-X) intensity was observed in the proximity of the water surface, however in the cases of Ar and $N_2$ with 0.5 SLM flow rate peaks shifted to the region below the water surface. Rotational temperature ($T_{rot}$) was estimated to be in the range of 900-3600 K, according to the carrier gas and flow rate, which corresponds to the arc-like-streamer discharge.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.330-339
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• 2008

Ground-based interceptors(GBI) comprise a major element of the strategic defense against hostile targets like Intercontinental Ballistic Missiles(ICBM) and reentry vehicles(RV) dispersed from them. An optimum design of the subsystems is required to increase the performance and reliability of these GBI. Propulsion subsystem design and optimization is the motivation for this effort. This paper describes an effort in which an entire GBI missile system, including a multi-stage solid rocket booster, is considered simultaneously in a Genetic Algorithm(GA) performance optimization process. Single goal, constrained optimization is performed. For specified payload and miss distance, time of flight, the most important component in the optimization process is the booster, for its takeoff weight, time of flight, or a combination of the two. The GBI is assumed to be a multistage missile that uses target location data provided by two ground based RF radar sensors and two low earth orbit(LEO) IR sensors. 3Dimensional model is developed for a multistage target with a boost phase acceleration profile that depends on total mass, propellant mass and the specific impulse in the gravity field. The monostatic radar cross section (RCS) data of a three stage ICBM is used. For preliminary design, GBI is assumed to have a fixed initial position from the target launch point and zero launch delay. GBI carries the Kill Vehicle(KV) to an optimal position in space to allow it to complete the intercept. The objective is to design and optimize the propulsion system for the GBI that will fulfill mission requirements and objectives. The KV weight and volume requirements are specified in the problem definition before the optimization is computed. We have considered only continuous design variables, while considering discrete variables as input. Though the number of stages should also be one of the design variables, however, in this paper it is fixed as three. The elite solution from GA is passed on to(Sequential Quadratic Programming) SQP as near optimal guess. The SQP then performs local convergence to identify the minimum mass of the GBI. The performance of the three staged GBI is validated using a ballistic missile intercept scenario modeled in Matlab/SIMULINK.

• Journal of the Korean Society of Safety
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• v.37 no.2
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• pp.1-9
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• 2022

Most factories deal with toxic or flammable chemicals in their industrial processes. These hazardous substances pose a risk of leakage due to accidents, such as fire and explosion. In the event of chemical release, massive casualties and property damage can result; hence, quantitative risk prediction and assessment are necessary. Several methods are available for evaluating chemical dispersion in the atmosphere, and most analyses are considered neutral in dispersion models and under far-field wind condition. The foregoing assumption renders a model valid only after a considerable time has elapsed from the moment chemicals are released or dispersed from a source. Hence, an initial dispersion model is required to assess risk quantitatively and predict the extent of damage because the most dangerous locations are those near a leak source. In this study, the dispersion model for initial consequence analysis was developed with three-dimensional unsteady advective diffusion equation. In this expression, instantaneous leakage is assumed as a puff, and wind velocity is considered as a coordinate transform in the solution. To minimize the buoyant force, ethane is used as leaked fuel, and two different diffusion coefficients are introduced. The calculated concentration field with a molecular diffusion coefficient shows a moving circular iso-line in the horizontal plane. The maximum concentration decreases as time progresses and distance increases. In the case of using a coefficient for turbulent diffusion, the dispersion along the wind velocity direction is enhanced, and an elliptic iso-contour line is found. The result yielded by a widely used commercial program, ALOHA, was compared with the end point of the lower explosion limit. In the future, we plan to build a more accurate and general initial risk assessment model by considering the turbulence diffusion and buoyancy effect on dispersion.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.91-100
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• 2023

The existing indoor localization method using Wi-Fi fingerprinting has a high collection cost and relatively low accuracy, thus requiring integrated correction of convergence with other technologies. This paper proposes a new method that significantly reduces collection costs compared to existing methods using Wi-Fi fingerprinting. Furthermore, it does not require labeling of data at collection and can estimate pedestrian travel paths even in large indoor spaces. The proposed pedestrian movement path estimation process is as follows. Data collection is accomplished by setting up a feature area near an indoor space intersection, moving through the set feature areas, and then collecting data without labels. The collected data are processed using Kernel Linear Discriminant Analysis (KLDA) and the valley point of the Euclidean distance value between two data is obtained within the feature space of the data. We build learning data by labeling data corresponding to valley points and some nearby data by feature area numbers, and labeling data between valley points and other valley points as path data between each corresponding feature area. Finally, for testing, data are collected randomly through indoor space, KLDA is applied as previous data to build test data, the K-Nearest Neighbor (K-NN) algorithm is applied, and the path of movement of test data is estimated by applying a correction algorithm to estimate only routes that can be reached from the most recently estimated location. The estimation results verified the accuracy by comparing the true paths in indoor space with those estimated by the proposed method and achieved approximately 90.8% and 81.4% accuracy in two experimental spaces, respectively.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.107-117
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• 2004

The growing demand for customer-response, made-to-order manufacturing and satisfactory delivery are stimulating the importance of commercial fleet management problem. Moreover, the rapid transformation to the customer-oriented multi-frequency, relatively small fleet, such as home delivery and Perishable goods, requiring prompt delivery and advanced real-time operation of vehicle fleets. In this paper we consider the vehicle routing problem(VRP) to minimize delivery completion time which is equal to the time that last customer wait for the vehicle in fleet operation. The mathematical formulation is different from those for the classical VRP which is minimizing cost/distance/time by running vehicles in manager's point of view. The key aspect of this model is not considering the return time from the last customer to depot in every vehicle path. Thereby, the vehicle dispatcher can afford to dynamically respond to customer demand and vehicle availability. The customer's position concerned with minimizing waiting time that may be applied for the delivery of product required freshness or delivery time. Extensive experiments are carried out to compare the performance of minimizing delivery completion time by using the ILOG Solver which has the advantage of solving quickly an interim solution very near an optimal solution. The experimental results show that the suggested model can easily find near optimal solution in a reasonable computational time under the various combination of customers and vehicles.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.1 s.11
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• pp.11-17
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• 1998

Recently, 3D GIS based on 3D geo-processing methodology and Internet environment are emerging issues in GIS fields. To design and implement 3D GIS, the strategic linkage of Java and VRML is first regarded: 3D feature format definition in the passion of conventional GIS including aspatial attributes, 3B feature indexing, 3D analytical operators such as selection, buffering, and Near, Metric operation such as distance measurement and statistical description, and 3D visualization. In 3D feature format definition, the following aspects are implemented: spatial information for 3D primitives extended from 2D primitives, multimedia data, object texture or color of VRML specification. DXF-format GIS layers with additional attributes are converted to 3D feature format and imported into this system. While, 3D analytical operators are realized in the form of 3D buffering with respect to user-defined point, line, polygon, and 3D objects, and 3D Near functions; furthermore, 'Lantern operator' is newly introduced in this 3D GIS. Because this system is implemented by Java applet, any client with Java-enable browser including VRML browser plug-in can utilize the new style of 3D GIS function in the virtual space. Conclusively, we present prototype of WWW-based 3D GIS, and this approach will be contribute to development of core modules on the stage of concept establishment and of real application model in future.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.2
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• pp.157-163
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• 2013

Purpose: This study was investigated weather watching 2D and 3D images effecting on accommodative function (AF), and differences between changes of AF by 2D and 3D. Methods: 50 subjects (male 30, female 20) aged 20's to 40's years old ($22.9{\pm}3.93$ years) who are available to watching 3D images were participated for this study. Accommodative amplitude (AA) by near point of accommodation (NPA), accommodative response (AR), positive and negative relative accommodation (PRA, NRA), accommodative facility (AF) were measured before, after watching 2D and 3D images at 1 m distance for 30 minutes respectively. Results: Accommodative amplitude after both watching 2D and 3D images decreased comparing to before watching images, and AA after watching 3D images was significantly lower than after watching 2D images. AR after both watching 2D and 3D images increased comparing to before watching images, but there was no difference between 2D and 3D. PRA and NRA were not significantly different between before, after watching 2D and 3D images. Accommodation speed by AF was increased for before watching ($13.52{\pm}3.32$ cpm) following by for after watching 2D images ($14.28{\pm}3.21$ cpm) and for watching 3D images ($14.90{\pm}3.27$ cpm). Conclusions: Watching images at close distance is effect to accommodation functions, and sequence of AA decrease of before watching images following by after watching 2D images and after watching 3D images may effect to asthenopia with same sequence as AA decrease. The results of increase of AF after watching images, specially 3D images show a possibility of vision therapy and further detail VT studies using 3D images are required in the future.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.11
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• pp.1128-1134
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• 2014

In this paper, the effects of a metamaterial slab with negative permeability in a magnetically coupled wireless power transfer system (WPT) in the overall performance are analyzed quantitatively in terms of the effective quality factors of the loop resonators and coupling coefficient considering the slab losses, based on an equivalent circuit. Using the ideal metamaterial slab(lossless slab), the WPT efficiency is improved considerably by the magnetic flux focusing. However, the practical lossy slab made of RRs or SRRs limits the significant enhancement of WPT efficiency due to the relatively high losses in the slab consisting of RRs or SRRs near the resonant frequency. For the practical loop resonator, other than a point magnetic charge, using the practical lossy metamaterial slab in order to improve the transfer efficiency, the width of the slab needs to be optimized somewhat less than the half of the distance between two loop resonators. For the low-loss slab with its loss tangent of 0.001, the WPT efficiency is maximized at 93 % when the ratio of the slab width and the distance between the two resonators is approximately 0.35, compared with 53 % for the case without the slab. The efficiency in case of employing the high-low slab(loss tangent: 0.2) is maximized at 61 % when the slab ratio is 0.25.