• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.291-298
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• 2012

Objective: The aim of this study is to predict Korean text entry on touchscreens using ACT-R cognitive architecture. Background: Touchscreen application in devices such as satellite navigation devices, PDAs, mobile phones, etc. has been increasing, and the market size is expanding. Accordingly, there is an increasing interest to develop and evaluate the interface to enhance the user experience and increase satisfaction in the touchscreen environment. Method: In this study, Korean text entry performance in the touchscreen environment was analyzed using ACT-R. The ACT-R model considering the characteristics of the Korean language which is composed of vowels and consonants was established. Further, this study analyzed if the prediction of Korean text entry is possible through the ACT-R cognitive model. Results: In the analysis results, no significant difference on performance time between model prediction and empirical data was found. Conclusion: The proposed model can predict the accurate physical movement time as well as cognitive processing time. Application: This study is useful in conducting model-based evaluation on the text entry interface of the touchscreen and enabled quantitative and effective evaluation on the diverse types of Korean text input interfaces through the cognitive models.

• Journal of the Korea Society of Computer and Information
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• v.20 no.3
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• pp.89-96
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• 2015

IT is widely used for biomechanics and AHRS sensor also be highlighted with small sized characteristics and price competitiveness in the field of motion measurement and analysis of sports. In this paper, we attach the AHRS to the figure skate shoes to measure the motion data like spin, forward/backward, jump, in/out edge and toe movement. In order to reduce the measurement error, we have adopted the sensors equipped with Madgwick complementary filtering and also use Euler angle to quaternion conversion to reduce the Gimbal-lock effect. We test and experiment the accuracy and execution time of the pattern recognition algorithms like PCA, ICA, LDA, SVM to show the recognition possibility of it on the basic motions of figure skating from the 9-axis trajectory information which is gathered from AHRS sensor. From the result, PCA, ICA have low accuracy, but LDA, SVM have good accuracy to use for recognition of basic motions of figure skating.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.2
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• pp.132-141
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• 2017

The objective of this study was to provide fundamental information on fish swimming behavioral properties. Acoustic data was collected at nighttime from the $10^{th}$ to $12^{th}$ March, 2016 near Yokji Island in the South Sea of South Korea, and was analyzed using the fish track technique. This technique is to identify groups of single targets, which shows a pattern of systematic movement. As a result, the differences of the behavioral properties such as depth, swimming speed, vertical direction, horizontal direction, tortuosity, and depth change among days were minor; however, statistical results (Welch analysis of variance) showed significant difference between days. Especially, the target strength (TS) of the $11^{th}$ were significantly different from the $10^{th}$ and $12^{th}$. It could be assumed that gizzard shad, which was the dominant species from the catch on the $11^{th}$ March, might have affected this difference. The correlation between TS and other properties was very week. The significant difference seemed even small differences of average values because of the large data volume.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.567-572
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• 2013

Mammals act as an important role in maintaining ecosystem, but direct observation is very difficult. Nevertheless, in order to understand the impact of various changes about a sudden environment, long-term monitoring through direct investigation is essential. This study investigated home range analysis using GPS tracking device and behavioral ecology of Korean waterdeer (Hydropotes inermis), indigenous and native species in Korea. Studies on ecological characteristics and home range of Korean waterdeer are insufficient. Therefore, we studied home range using the GPS technique for critical point of existing research. Data showed the active movement in daytime ($44.1km^2$) than night ($30.0km^2$) and large area of activity in winter ($3.7km^2$) and spring ($44.1km^2$) than summer($0.04km^2$) and autumn ($0.01km^2$). The most used area of Korean waterdeer was forested area and wetland, agricultural area, waters in order of frequency based on the land coverage map. Our research represents overall characteristics of Korean water deer due to measurement of area of activity. However, this research signified behavioral ecology for Korean waterdeer, and further investigation in necessary.

• Journal of the Korean Society of Radiology
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• v.8 no.2
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• pp.51-56
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• 2014

We analyzed how insole affects the dynamic stability and the balance while a body moves or stops. Specially we've sorted out variations of individual balance ability while we make a longitudinal arch stop artificially as a usual situation(just standing and putting one's weight). We found ten men and girls each with suitable feet for our experimentation as the subject of investigation and made individual insole for them by measuring medial longitudinal arch. Then we compared before and after movement of the power point of application and a pattern of COP using the Tetrax balance equipment. We found out it is better for balance ability when we wear insoles. It turned out to be helpful for increasing balance ability of body to use insole which supports medial longitudinal arch of longitudinal arch well.

• Economic and Environmental Geology
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• v.31 no.4
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• pp.277-290
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• 1998

The purpose of this research is to investigate the dispersion pattern of gold during skarnization and genesis of gold mineralization in the Sangdong skarn deposits. The Sangdong scheelite orebodies are embedded in the Cambrian Pungchon Limestone and limestone interbedded in the Myobong Slate of the Cambrian age. The tungsten deposits are classified as the Hangingwall Orebody, the Main Orebody and the Footwall Orebody as their stratigraphic locations. Recently, the Sangdong granite of the Cretaceous age (85 Ma) were found by underground exploratory drillings below the orebodies. In geochemisty, the W, Mo, Bi and F concentrations in the granite are significantly higher than those in the Cretaceous granitoids in southern Korea. Highest gold contents are associated with quartz-hornblende skarn in the Main Orebody and pyroxene-hornblende skarn in the Hangingwall Orebody. Also Au contents are closely related to Bi contents. This could be inferred that Au skarns formed from solutions under reduced environment at a temperature of $270^{\circ}C$. According to the multiple regression analysis, the variation of Au contents in the Main Orebody can be explained (87.5%) by Ag, As, Bi, Sb, Pb, Cu. Judging from the mineralogical, chemical and isotope studies, the genetic model of the deposits can be suggested as follows. The primitive Sangdong magma was enriched in W, Mo, Au, Bi and volatiles (metal-carriers such as $H_2O$, $CO_2$ and F). During the upward movement of hydrothermal ore solution, the temperature was decreased, and W deposits were formed at limestone (in the Myobong Slate and Pungchon Limestone). In addition, meteoric water influx gave rise to the retrogressive alterations and maximum solubility of gold, and consequently higher grade of Au mineralization was deposited.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.489-497
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• 2015

To reveal the spatial and temporal variability in the distribution, growth, and maturation of skipjack tuna Katsuwonus pelamis in the western tropical Pacific, we compared two El $Ni{\tilde{n}}o$-Southern Oscillation (ENSO) signals and the sea surface temperature (SST) in the main fishing area with fishery and biological data. An index of skipjack tuna distribution was calculated using Korean purse seine fishery data from 1985 to 2003. Biological data for skipjack tuna were collected monthly from Korean catches during the 1994-2003 period. The catch was more closely related to the SST in the main fishing area than to the ENSO signals. However, cross-correlated function analysis showed delayed interactions between abiotic and biotic factors. The El $Ni{\tilde{n}}o$ events preceded the eastward movement of the fishing center by 2-3 months. El $Ni{\tilde{n}}o$ had a positive effect on the skipjack tuna catch, and the change in the Southern Oscillation Index (SOI) preceded the catch fluctuation by ca. 5-7 months. In addition, negative El $Ni{\tilde{n}}o$ effects on gonad maturation and the mean length of skipjack tuna were detected with time lags of 12 and 7 months, respectively. The length frequency indicated that the regime-specific growth pattern at each discrete period seemed to be related to the ENSO.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.347-355
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• 2006

Anyang Stream including its main branch is the biggest branch stream of Han River in Korea. The geological and geomorphological characteristics were investigated to the affected area of Anyang Stream, in which rainfall characteristic was analyzed. The water quality surveyed that the analysis of water pollution used to biotic index and biological water pollution. The rainfall pattern in this area was like to that of typical Korea, but the rate of trigger and runoff during summer season(June~August) is more higher than mean of Korea. Before 2003, a dried stream is severe status, which was due to abundant runoff, but this status are improved. After 1997, water quality of stream is recovering status such as water pollution of stream steeply decreased. Especially after 2003, this trend is more quickly improved. Although, owing to the increasing of a T-N and SS at upstream wastewater were due to bad collection of industrial factories, livestock's and mans living, the water quality worsted at upstream. Water quality in total section of main stream was severely contaminated that water-quality limit is 5 with polysaprobic by water self-purification. That of main branch was 1~3limits with ${\alpha}$- and ${\beta}$-mesosaprobic in Anyang city area, But water quality in all area about another branch of Anyang stream except Anyang city area was almost under of 3 grades. Though trying of Anyang city for recover movement(completion of 2nd Sewage Treatment Plant and Water supply pipe system) on Anyang stream, water pollution states of upper branch in Anyang stream was not better than its of 2002 because it may be difference of control area on other cities.

• Physical Therapy Korea
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• v.8 no.4
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• pp.1-16
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• 2001

회전(turning)은 보행 중 방향을 바꾸는 운동 기술(motor skill)이고, 회전 전략(turning strategy)은 회전을 완수하는데 사용되는 일반적 행동 전형(generalized movement pattern)이다. 회전에 대한 보행속도의 영향은 분명하지 않다. 이 연구의 목적은 보행속도의 돌기 전략에 대한 영향을 분석하고 보행속도의 하지 내외 회전(internal and external rotation)에 대한 영향을 분석하는 것이다. 건강한 젊은 성인 15명이 이 연구에 자발적으로 참여하였다. 맥리플렉스 측정 장치(MacReflex measurement system)가 동작 분석(motion analysis)을 위해 사용되었다. 각각의 자원자들은 보행 중 90도 왼쪽으로 회전을 10회씩 완수하였다. 각각의 시도마다 보행속도를 다르게 하기 위해서 세 가지의 다른 요구들(slow, regular, fast)이 임의적으로 주어졌고 각각의 실제 보행속도가 자원자의 무게중심 변화에 따라 구해졌고 요구별 평균이 구해졌다. 회전 안쪽 발의 스핀(in side foot spin)은 보행속도가 증가함에 따라 증가했지만, 회전 바깥쪽 발의 스핀(out side foot spin)은 보행속도와 상관이 없었다. 하지의 내외 회전은 보행속도와는 상관이 없었지만, 같은쪽 발의 스핀과는 역관계가 있었다. 회전은 발 스핀이 있는 돌기와 발 스핀이 없는 돌기로 구분되는 것이 합당한 듯 하다. 제한된 시간과 공간 내에서 스핀은 보행속도가 빨라질수록 몸의 전방 운동량(forward momentum)에서 몸의 전방 운동량(forward momentum)으로의 전환이 스핀이 없는 회전 시보다 효율적이다. 고관절의 내외 회전 근육들은 회전전략에 상관없이 회전되는 동안 몸의 역학(body mechanics)을 조절하는데 중요한 역할을 맡고 있는 것으로 보인다. 앞으로 회전 시 몸의 생체 역학적 그리고 신경 근육적 기전들(biomechanical and neuromuscular mechanisms)을 밝히는 연구들이 필요하다.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.3
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• pp.199-203
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• 2016

A brain-computer interface or BCI provides an alternative method for acting on the world. Brain signals can be recorded from the electrical activity along the scalp using an electrode cap. By analyzing the EEG, it is possible to determine whether a person is thinking about his/her hand or foot movement and this information can be transferred to a machine and then translated into commands. However, we do not know which information relates to motor imagery and which channel is good for extracting features. A general approach is to use all electronic channels to analyze the EEG signals, but this causes many problems, such as overfitting and problems removing noisy and artificial signals. To overcome these problems, in this paper we used a new optimization method called the Fruit Fly optimization algorithm (FOA) to select the best channels and then combine them with CSP method to extract features to improve the classification accuracy by linear discriminant analysis. We also used particle swarm optimization (PSO) and a genetic algorithm (GA) to select the optimal EEG channel and compared the performance with that of the FOA algorithm. The results show that for some subjects, the FOA algorithm is a better method for selecting the optimal EEG channel in a short time.