• Journal of the Korean Geographical Society
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• v.45 no.6
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• pp.806-819
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• 2010

Population data has been essential and fundamental in spatial analysis and commonly aggregated into political boundaries. A conventional method for population distribution estimation was a regression model with land use data, but the estimation process has limitation because of spatial autocorrelation of the population data. This study aimed to improve the accuracy of population distribution estimation by adopting a Regression-Kriging method, namely RK Model, which combines a regression model with Kriging for the residuals. RK Model was applied to a part of Seoul metropolitan area to estimate population distribution based on the residential zones. Comparative results of regression model and RK model using RMSE, MAE, and G statistics revealed that RK model could substantially improve the accuracy of population distribution. It is expected that RK model could be adopted actively for further population distribution estimation.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.7 no.2
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• pp.5-22
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• 2001

The purpose of this study was to investigate the balancing training effect on weight bearing ratio and postural sway on the unstable surface for the CVA patients with balance disability. The inclusion criteria were walking independently 20m distances. Eighteen subjects, 4 with right and 14 with left hemiplegic patients were participated in this study. The range of age was from 35 to 75 and the duration from onset time was from 1 to 38 months. The intervention program including balancing training that they were introduced for 10 minutes every other day during 12 weeks to experimental group, and general therapeutic exercise to control group. The result of this study were as following; 1. The balancing training on the unstable surface showed that the postural sway of left/right distribution would appear more effective on sitting with eyes opened. 2. The balancing training on the unstable surface showed that the postural sway of forward/rear distribution, left/right distribution and distance would appear more effective on standing with eyes opened. 3. The balancing training on unstable surface would increase more effective on the weight-bearing ratio of left/right difference and frequency. 4. The balancing training on unstable surface was statistical significant on the postural sway of left/right distribution and area in experimental group. and it was statistical significant on the postural sway of forward/rear distribution, left/right distribution and distance in control group, too.

• Journal of Electrical Engineering and Technology
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• v.1 no.4
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• pp.435-447
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• 2006

This paper presents an application of the parallel Adaptive Evolutionary Algorithm (AEA) to search an optimal solution of the service restoration in electric power distribution systems, which is a discrete optimization problem. The main objective of service restoration is, when a fault or overload occurs, to restore as much load as possible by transferring the de-energized load in the out of service area via network reconfiguration to the appropriate adjacent feeders at minimum operational cost without violating operating constraints. This problem has many constraints and it is very difficult to find the optimal solution because of its numerous local minima. In this investigation, a parallel AEA was developed for the service restoration of the distribution systems. In parallel AEA, a genetic algorithm (GA) and an evolution strategy (ES) in an adaptive manner are used in order to combine the merits of two different evolutionary algorithms: the global search capability of the GA and the local search capability of the ES. In the reproduction procedure, proportions of the population by GA and ES are adaptively modulated according to the fitness. After AEA operations, the best solutions of AEA processors are transferred to the neighboring processors. For parallel computing, a PC cluster system consisting of 8 PCs was developed. Each PC employs the 2 GHz Pentium IV CPU and is connected with others through switch based fast Ethernet. To show the validity of the proposed method, the developed algorithm has been tested with a practical distribution system in Korea. From the simulation results, the proposed method found the optimal service restoration strategy. The obtained results were the same as that of the explicit exhaustive search method. Also, it is found that the proposed algorithm is efficient and robust for service restoration of distribution systems in terms of solution quality, speedup, efficiency, and computation time.

• Journal of Energy Engineering
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• v.29 no.2
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• pp.40-60
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• 2020

When various kinds of products are produced from a single energy system, the methodology which allocates the common cost to each product cost is very important because it is directly related with the profit and loss of producer and purchaser. In the cost allocation methodology of electricity and heat for CHP, there are heat method, work method, benefit distribution method, exergy method, and so on. Benefit distribution method is the most widely known worldwide, and exergy method is widely recognized among thermal engineers. As a result of review, it is judged that the rationality of benefit distribution method is low because the result deviates from common sense, and the rationality of exergy method is high because the result consistent with common sense. In accounting, it is calculated as merit methodology and the result is used for negotiations between producer and buyer, but In thermal engineering, the rationality of exergy methodology is described only as a thesis. The purpose of this study is to compare and examine the rationality of merit methodology and exergy methodology, and the aim is to describe in detail in order that producer and buyer can understand the rationality of each methodology.

• Korean journal of communication and information
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• v.66
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• pp.5-27
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• 2014

The past, present, and future of online journalism in Korea are inextricably bound up with the portal site news services. In traditional journalism, finite news media took hold on news consumption completely because of performing news production and distribution simultaneously. Since then, in the age of multi-media and multi-channel, the audience selection has become more important because of greatly increasing news media and then exploding news production. In online journalism, the news distribution have emerged as the most important field because of the intensive consuming the portal site news services making use of various news easier, the characteristic of news consumption focusing on not news media brands but news media contents, etc. Therefore, the news present landscape of Korean journalism oriented news distribution has been completed by that the portal site news services became the symbol of online journalism. That the portal site news services performing only news distribution have more influence than the paper based online newspapers and Internet based online newspapers producing news means the change of media power. By this, a conflict between news media and portal site news services appears at all times.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.3
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• pp.30-36
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• 2013

This paper presents a method to estimate a storage life for loss of stabilizer content as storage periods using accelerated life test data. The estimate of storage life based on deterministic accelerated life test and degradation data cannot describe a condition distribution and storage life distribution. Previously, the method to show the condition distribution and storage life distribution by using gamma process has been studied. But it has limitation because it is impossible to collect the deterioration data at initial production phase. The estimated storage life presented by this study shows the similar value to previous studies and the method can describe the condition distribution and storage life distribution. So, the estimation method studied in this paper can be used for a life cycle management about deterioration of propellant for propulsion unit or components of missile, too.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.9
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• pp.828-837
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• 2004

The present study investigated two-phase flow distribution, phase separation and pressure drop in multi-microchannel tubes under adiabatic condition. The test section consisted of inlet and outlet headers with the inner diameter of 19.4㎜ and 15 parallel microchannel tubes. Each microchannel tube brazed to the inlet and outlet headers and had 8 rectangular ports with the hydraulic diameter of 1.32㎜. The key experimental parameters were orientation of header (horizontal and vertical), flow direction of refrigerant into the inlet header (in-line, parallel and cross flow) and inlet quality (0.1, 0.2 and 0.3). It was found that the orientation of the header had relatively large effect on the flow distribution and phase separation, while the inlet quality didn't affect much on them. The horizontal header showed the better flow distribution and phase separation characteristics than the vertical one. The parallel flow condition with the horizontal header showed the best performance for the flow distribution and phase separation characteristics under the test conditions. Two-phase pressure drops through the microchannel tubes with the horizontal header were higher than those of the microchennel tubes with the vertical header due to gravitational effect.

• Korea journal of population studies
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• v.26 no.2
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• pp.175-195
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• 2003

This paper investigates spatial distribution of the knowledge-information occupations by utilizing Geographical Information System(GIS). The knowledge-information occupations, comprised mainly of professionals, engineers and managers, have played a key role in the knowledge-based information society. The uneven development of bureaucratization and informatization among regions have resulted in unequal spatial distribution of the knowledge-information occupations. Analysis of 1995 and 2000 Census shows that these occupations tend to concentrate in some major metropolitan areas, while the other areas show rather traditional occupational structure. This spatial unequality has been also found in the occupational distribution within Seoul. This tendency of spatial concentration in the occupational distribution inherited from the industrial society and is not going to diminish in the knowledge-information society. More aggressive policies to make the most of decentralizing impacts of information and communication technologies should be implemented to counter-balance this tendency.

• Journal of Korean Medicine for Obesity Research
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• v.4 no.1
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• pp.23-31
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• 2004

Background: Obesity is associated with menstrual disorder. Especially, upper-body obesity affects on female reproductive function. Objectives: The goals were to investigate relation between fat distribution and menstrual disorder in obese pre-menopausal Korean females. The hypothesis were tested that there is a relation between upper body obesity and menstrual disorder. Design: A cross-sectional evaluation of 66 Females (baseline age $32.15{\pm}7,32)$ with body mass index $31.22{\pm}4.05\;kg/m^2$. Body composition was measured using bioimpedence analysis (BIA) and anthropometry was done by same observer. VAS and Multidimensional verval rating scale(MVRS) were checked for menstrual pain. Dual-Energy X-ray Absorptiometry (DXA) was measured for evaluating body fat distribution. Menstrual disorder and body fat distribution were compared using statistical methods. Results: TLFR and WH ratio was higher in menstrual cyclic disorder group than controls. There was negative relationship between VAS and TLFR. Conclusions: The data shows that disorder of menstrual cycle was associated with upper body obesity. WH ratio could be one of the factor of menstrual disorder. VAS was correlated with lower body obesity. Further studies for role of upper body fat distribution on female reproductive function and relationship between menstrual pain and fat distribution thought to be needed.

• Journal of Korea Water Resources Association
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• v.48 no.4
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• pp.299-308
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• 2015

The aim of this study is that a theoretical formula for estimating the one-dimensional longitudinal dispersion coefficient is derived based on a transverse distribution equation for the depth averaged stream-wise velocity in open channel. In "Part I. Theoretical equation for stream-wise velocity" which is the former volume of this article, the velocity distribution equation is derived analytically based on the Shiono-Knight Method (SKM). And then incorporating the velocity distribution equation into a triple integral formula which was proposed by Fischer (1968), the one-dimensional longitudinal dispersion coefficient can be derived theoretically in "Part II. Longitudinal dispersion coefficient" which is the latter volume of this article. The proposed equations for the velocity distribution and the longitudinal dispersion coefficient are verified by using observed data set. As a result, the non-dimensional longitudinal dispersion coefficient is inversely proportional to square of the Manning's roughness coefficient and the non-dimensional transverse dispersion coefficient, and is directly proportional to square of the aspect ratio (channel width to depth).