• Journal of Korean Institute of Industrial Engineers
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• v.14 no.2
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• pp.53-61
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• 1988

Games such as baseball, soccer are scheduled by a given game type such as tournament, league or their mixed form. The objective of this paper is to find an efficient game-scheduling method with respect to traveling distance, break-time and other conditions. In this paper we first present two models which minimize traveling distance. The first model that a match is played once each other is solved by a heuristic method. In the second model that a match is played more than once, teams are paired by a modified 0 - 1 programming, and the pairs are rearranged in order to generate a number of workable schedules. Then Expert Systems is applied to solve breake-time and other conditions. In order to represent expertise's knowledge effectively, we present a new design of knowledge-base and data-base, inference engine including many rules and meta-rules which controls the global system. In knowledge-base, binary relation among various attributes is used to ease not only knowledge acquisition but also system execution.

• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.872-878
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• 2000

In this paper a computer programming for the expression of nearest neighbor atoms in face-centered cubic (FCC) and body-centered cubic (BCC) crystals was suggested as one of the approaches to understand each of the crystal structure. By using this computer programming the distance values between a reference atom and the nearest neighbor atoms, and the numbers of the nearest neighbor atoms were calculated ane compared for the FCC and BCC crystals. In this algorithm, the positions of the atoms in a crystal were defined as two categories: the corner atoms and face- or body-centered atoms, and considered respectively. For the same order of nearest neighbor atoms except the second order ones the distance values form the reference atom were smaller in the FCC crystals than those in the BCC. Also, the numbers of he first and third nearest neighbor atoms n the FCC crystals were larger than those in the BCC. This difference was explained by the comparison of each atomic packing ratio of the FCC and BCC crystals. The algorithm used in this programming can also be expanded to the analysis of other crystal structures.

• Journal of the Ergonomics Society of Korea
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• v.10 no.1
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• pp.11-22
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• 1991

This paper aims to examine experimentally the difference of subjectively measured degree of depth between two dimensional (2D) and three dimensional (3D) images. For this paper, two experiments were conducted; in the first experiment, the subjects were asked to estimate the distance between two objects presented with different depths, while in the second experiment, the subjects' role was to rank three objects in the order of distance from the screen. In both experiments, the objects were presented either in 2D or 3D images. The results of the experiments show that the use of 3D images can induce more accurate and more stable estimates of distance than the use of 2D images. However, it is also noted that the absolute degree of depth is not the unique criteria utilized by the subjects for the distinction of small differences of depth.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.7
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• pp.711-717
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• 2007

Location information will become increasingly important for future Pervasive Computing applications. Location tracking system of a moving device can be classified into two types of architectures: an active mobile architecture and a passive mobile architecture. In the former, a mobile device actively transmits signals for estimating distances to listeners. In the latter, a mobile device listens signals from beacons passively. Although the passive architecture such as Cricket location system is inexpensive, easy to set up, and safe, it is less precise than the active one. In this paper, we present a passive location system using Cricket Mote sensors which use RF and ultrasonic signals to estimate distances. In order to improve accuracy of the passive system, the transmission speed of ultrasound was compensated according to air temperature at the moment. Upper and lower bounds of a distance estimation were set up through measuring minimum and maximum distances that ultrasonic signal can reach to. Distance estimations beyond the upper and the lower bounds were filtered off as errors in our scheme. With collecting distance estimation data at various locations and comparing each distance estimation with real distance respectively, we proposed an equation to compensate the deviation at each point. Equations for proposed algorithm were derived to calculate relative coordinates of a moving device. At indoor and outdoor tests, average location error and average location tracking period were 3.5 cm and 0.5 second, respectively, which outperformed Cricket location system of MIT.

• KIEAE Journal
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• v.4 no.4
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• pp.35-44
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• 2004

In Korea, the apartment buildings have been constructed recently in large quantities to provide housing due to the gravitation of population towards large cities. However, because of this trend toward high-rise apartment, a number of problems are occurred such as the deterioration of comfort in the dwelling environment and the lack of solar access right in apartment buildings. In the building law, the sunshine hour and the minimal separated distance between apartment buildings as regulated as the criteria for the site planning. Most of site planners, however, designed the apartment site only following minimum separated distance. As a result, the problem of sunshine hours lack is caused and legal dispute concerning solar access right is also arisen. The purpose of this study is to improve solar access right regulation and to help site design of apartment planning. Accordingly, we execute empirical analysis based on computer simulation in order to find suitable separated distance between typically designed apartment buildings. First, we estimated sunshine hours according to independent building orientation, height, and length. Second, we calculated sunshine hours in various case of apartment arrangement; parallel type, courtyard type, tower type and etc. with various separated distance.

• The Journal of Korean Physical Therapy
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• v.33 no.1
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• pp.16-20
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• 2021

Purpose: This study examined the effects of the type of video contents used for action observations on the ability to control posture. Methods: The participants were 48 healthy adults. The two hands of the participants were crossed on both shoulders, and the other foot was placed in a straight line in front of the target to allow them to watch a video of the monitor. The videos were presented in random order with three video contents (natural, stable balance posture, and unstable balance posture) consisting of 30 seconds each. A 15-second resting time was given between each video. During action observation using various video content forms, the posture control ability was measured using a TekScan MetScan^® system. Results: The results revealed statistically significant differences in the area of movement and the distance by COP and distance by the type of action-observation videos, and the distance by the anteroposterior and mediolateral sides (p<0.05). The stable balance posture and unstable balance posture video showed significant differences in the distance by the COP, anteroposterior, and mediolateral distance. (p<0.05) Conclusion: This study suggests that choosing the contents of the videos is important during action-observation training, and action-observation training can help improve postural control.

• Journal of the Optical Society of Korea
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• v.14 no.3
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• pp.228-234
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• 2010

This paper presents the joint characteristic function of the first- and second-order polarization-modedispersion (PMD) vectors in installed optical fibers that are almost linearly birefringent. The joint characteristic function is a Fourier transform of the joint probability density function of these PMD vectors. We regard the random fiber birefringence components as white Gaussian processes and use a Fokker-Planck method. In the limit of a large transmission distance, our joint characteristic function agrees with the previous joint characteristic function obtained for highly birefringent fibers. However, their differences can be noticeable for practical transmission distances.

• The Journal of Korean Association of Computer Education
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• v.17 no.2
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• pp.53-64
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• 2014

The purpose of the study is to develop a scale for measuring learning outcomes in the distance teacher training programs. In order to develop the measurement instrument, the forty-four items were developed based on the literature review and ten experts' review. For data collection, a web-based survey was conducted among teachers taking a distance teacher training program at National Education Training Institute. With the data of 205 sample size from the first survey, the Exploratory Factor Analysis was conducted and seven factors were identified. In order to validate the test, the Confirmatory Factor Analysis was performed with 293 respondents from the second survey. In conclusion, this study reports the reliability and validity of a scale for learning outcomes in distance teacher training programs consisting of seven factors with 34 items; 1) system quality, 2) content quality, 3) service quality, 4) use, 5) benefit, 6) satisfaction, 7) transfer.

• Journal of the Korean Professional Engineers Association
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• v.25 no.4
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• pp.102-108
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• 1992

This study was carried to find out the soil characteristics of landslide site and to develope landslide prediction method by seismic refraction prospecting. For these aims, landslide condition and travel time were investigated at 68 Landslide sites over the country during 1990 to 1991. The results were as follows. 1. The surface of rupture was included mainly in C layer. Its Hardness was less than 3kg / $\textrm{cm}^2$ at the upper pare of landslide. 2. When the profile line length was 20m, the range of travel time was 40 to 90 msec. The travel time did not differ between bedrocks. 3. Refraction distance ranged from 1 to 7m and mean of that was 2.5m. Travel time was increased according to receiving distance without large variance in the refraction distance but that was appeared large variance out of the refraction distance on slope that has shallow soil depth and discontinuous ground surface. Therefore, the spread distance must be shorten to 10-l5m. 4. The seismic velocity at the first layer(layer of rupture) was less than 500m1sec by degree of weathering and the velocity at the second layer decreased in order of Granite> Granitic gneiss >Sedimentary rock. 5. The first layer observed by seismic refraction was contained C layer that has parent material and weathered rocks of hardness 10-20kg/$\textrm{cm}^2$. 6. Among the range of seismic velocity was less than 200m/sec in 63% of the total plots, 200-300m/sec in 34% and 300-500m /sec in 3%. 7. There was a proportional relationship between seismic prospecting soil depth and executive soil depth, and seismic propection soil depth was about 10 to 20cm deeper than the order.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.400-406
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• 2009

In this study, in order to find the movement of polluted substance that is flown into the river and the characteristics of dispersion, the experiment that used the RI (Radioactive Isotope) tracer in the river was undertaken, and by using the experiment result, the figure modelling was undertaken to analyze the general type of pollutant dispersion. In addition, in order to calculate more accurate dispersion range and moving time, the experiment was done in about 2km from the measuring points of Namdae Stream around the Yongdam Dam of the upper Geum River to the lower stream. In order to find out the flow of river and dispersion of polluted substance, RMA (Resource Modeling Associates)-2 and RMA-4 program are used in study. The site experiment using the RI was implemented for the experiment in the applied area and the same area, and the distance between each zone was set for 1km with the slight difference for site situation and measured the density date of one second distance through the NaI apparatus to measure the density data of one second interval. On the basis of this measured data, it is compared and analyzed with the result of figure copy of the models to make the comparison and analysis of density distribution following the change in expansion coefficient that makes great influence on expansion range and dispersion in natural rivers.