• Journal of the Ergonomics Society of Korea
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• v.35 no.1
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• pp.11-27
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• 2016

Objective: The purpose of this study was to develop and evaluate high technology adaptive driving controls, such as mini steering wheel-lever system and joystick system, for the people with physical disabilities in the driving simulator. Background: The drivers with severe physical disabilities have problems in operation of the motor vehicle because of reduced muscle strength and limited range of motion. Therefore, if the remote control system with driver-by-wire technology is used for adaptive driving controls for people with physical limitations, the disabled people can improve their quality of life by driving a motor vehicle. Method: We developed the remotely controlled driving simulator with drive-by-wire technology, e.g., mini steering wheel-lever system and joystick system, in order to evaluate driving performance in a safe environment for people with severe physical disabilities. STISim Drive 3 software was used for driving test and the customized Labview program was used in order to control the servomotors and the adaptive driving devices. Thirty subjects participated in the study to evaluate driving performance associated with three different driving controls: conventional driving control, mini steering wheel-lever controls and joystick controls. We analyzed the driving performance in three different courses: straight lane course for acceleration and braking performance, a curved course for steering performance, and intersections for coupled performance. Results: The mini steering wheel-lever system and joystick system developed in this study showed no significant statistical difference (p>0.05) compared to the conventional driving system in the acceleration performance (specified speed travel time, average speed when passing on the right), steering performance (lane departure at the slow curved road, high-speed curved road and the intersection), and braking performance (brake reaction time). However, conventional driving system showed significant statistical difference (p<0.05) compared to the mini steering wheel-lever system or joystick system in the heading angle of the vehicle at the completion point of intersection and the passing speed of the vehicle at left turning. Characteristics of the subjects were found to give a significant effect (p<0.05) on the driving performance, except for the braking reaction time (p>0.05). The subjects with physical disabilities showed a tendency of relatively slow acceleration (p<0.05) at the straight lane course and intersection. The steering performance and braking performance were confirmed that there was no statistically significant difference (p>0.05) according to the characteristics of the subjects. Conclusion: The driving performance with mini steering wheel-lever system and joystick control system showed no significant statistical difference compared to conventional system in the driving simulator. Application: This study can be used to design primary controls with driver-by-wire technology for adaptive vehicle and to improve their community mobility for people with severe physical disabilities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.739-744
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• 2017

Elastic deformation and fatigue damage can cause the permanent deformation of a kart's frame during turning, affecting the kart's driving performance. A kart's frame does not contain any suspension or differential devices and, therefore, the dynamic behavior caused by torsional deformation when driving along a curve can strongly affect these two kinds of deformations. To analyze the dynamic behavior of a kart along a curved section, the GPS trajectory of the kart is obtained and the torsional stress acting on the kart-frame is measured in real time. The mechanical properties of leisure and racing karts are investigated by analyzing their material properties and conducting a tensile test. The torsional stress concentration and frame distortion are investigated through a stress analysis of the frame on the basis of the obtained results. Leisure and racing karts are tested in each driving condition using driving analysis equipment. The behavior of a kart when being driven along a curved section is investigated through this test. Because load movement occurs owing to centrifugal force when driving along a curve, torsional stress acts on the kart's steel frame. In the case of a leisure kart, the maximum torsional stress derived from the torsional fatigue limit was found to be 230 MPa, and the torsional fatigue limit coefficient was 0.65 when driving at a speed of 40 km/h. Furthermore, the driving elements during the cornering of a kart were measured based on an actual auto-test after installing a driving measurement system, and the driving behavior of the kart was analyzed by measuring its vertical displacement.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.580-586
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• 2016

The ultra-long stroke engine was developed to generate greater power at lower speeds than previous designs to enhance the propulsion efficiency. The torsional exciting force, on the other hand, was increased significantly. Therefore, it is possible to control the torsional vibration of its shaft system equipped with the fuel efficient ultra-long stroke engine by adopting a damper although the torsional vibration could be controlled adequately by applying tuning and turning wheels on the engine previously. In this paper, the dynamic characteristics of a viscous-spring damper used to control the torsional vibration of the corresponding shaft system are reviewed and then examined to determine what vibration characteristics might be used to optimize the viscous-spring damper. In some cases, operators of eco-ships have recently experienced the problem of delayed RPM acceleration. It has been suggested that the proper measures for controlling the torsional vibration in the shaft system should involve adjusting the design parameters of its damper determined by the optimum damper design theory to avoid the fatigue damage of shafts.

• The Korean Journal of Mycology
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• v.45 no.1
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• pp.43-53
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• 2017

In this study, we analyzed the densities and taxonomic characteristics of various microorganisms that play important roles in Agaricus bisporus culture medium composting, and examined changes in the levels of decomposition-related enzymes secreted by these microorganisms. Various microorganisms such as thermophilic bacteria, actinomycetes, fluorescent Pseudomonas spp., and filamentous bacteria are closely associated with culture medium composts of Agaricus bisporus. The population densities of microorganisms change, and harmful bacteria disappear during thermophilic composting. Psychrobacter sp., Pseudomonas sp., Bacillus sp., and Pseudoxanthomonas sp. accounted for the highest proportion of bacteria in the culture media during outdoor composting, whereas Bacillus sp. and Psychrobacillus sp. were dominant after pasteurization. Cellulose and hemicellulose enzymes of the microorganisms were important at an early stage of rice straw composting and after decomposition of carbon sources, respectively. Microorganisms that secreted these enzymes were present in the second and third turning stage of composting.

• Journal of Korea Water Resources Association
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• v.55 no.7
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• pp.505-513
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• 2022

Recently, uncertainty in predicting available water resources is gradually increasing due to climate change and extreme weather conditions. Social interest in water management such as flood and drought prevention is also increasing, and after the unification of water management implemented in 2018, domestic water management is facing a major turning point. As part of such strengthening of water management capabilities, various studies are being conducted to utilize a hydropower dam for flood control and water supply purposes, which was mainly operated for hydroelectric power generation. However, since the dam evaluation methods developed based on a multi-purpose dam are being applied to hydropower dams, an additional evaluation approach that can consider the characteristics of hydropower dams is required. In this study, a new water supply capacity evaluation method is presented in consideration of the operational characteristics of hydropower dams in terms of water supply, and a connected reservoir simulation method is proposed to evaluate the comprehensive water supply capacity of a dam group operating in a river basin. The presented method was applied to the hydropower dams located in the Bukhan River basin, and the results of the water supply yield of individual dams and multi-reservoir systems were compared and analyzed. In the future, the role of hydropower dams for water supply during drought is expected to become more important, and this study can be used for sustainable domestic water management research using hydropower dams.

• Journal of Animal Environmental Science
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• v.14 no.2
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• pp.129-138
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• 2008

This study was carried out to investigate the operating characteristics, water balance and chemical properties of compost during the composting with pig slurry on-farm trial. The composting plant with sawdust pile filteration was done in a forced aeration inside a house and equipped with a turning machine moving on a rails. The composting pit was 4.6m wide, 53m long and the maximum height was 2m. A field scale aerobic composting facility was tested the composting efficiency of high moisture pig slurry. The sawdust materials remained 6 months. Pig slurry was added to compost pile every other day during 6 months run. The temperature in compost pile and compost house, and input and output of moisture were measured during composting process. The result are summarized as follows; 1. The temperature of compost was varied in range of at $22.4^{\circ}C{\sim}71.1^{\circ}C$. After turning, the composting temperature decreased to $50^{\circ}C{\sim}36^{\circ}C$ during $3{\sim}5$ hours, and then raised to $64.5^{\circ}C$ 2. The temperature of compost house was maintained $20^{\circ}C{\sim}30^{\circ}C$, and relative humidity was varied in range of $50{\sim}99%$. 3. BOD, CODcr and SS of leachate water was reduced 89.5%, 81.2%, 97.5%, respectively. 4. The content of heavy metal in the final compost was lower those of Korea standards. 5. The amount of effluent was 10.2%. Total evaporation during composting Period were 74.8%. The amount of slurry per $1m^3$ sawdust was $3.16m^3$ without treatment of effluent output.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.1
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• pp.92-100
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• 1997

Objective：The objective of this study is to examine the clinical characteristics and behavioral comorbidity of patients with Tourette’s disorder. Method：Subjects consisted of 157 patients with Tourette’ disorder diagnosed by DSM-IIIR, who were examined and diagnosed from Jan. 1988 to May 1994 at the Tourette’s Clinic of Yonsei University Medical Center. Characteristics and behavioral comorbidity of Patients were assessed by a semi-structured interview schedule. Behavioral problems like hyperactivity, obsession-compulsion, self destructiveness, enuresis, sleep problem were assessed by global clinical impression. Results：The mean age of patients was 14.49(${\pm}7.99$) years. Patients consisted of 138 males (87.9%) and 19 females(12.1%). The sex ratio was 7：1, showing a male preponderance. The number of right-handers was 133(84.7%), and the number of non-right handers was 24(15.3%). Mean age of onset was 8.85(${\pm}4.56$) years, ranging from 2-to-16 years. More than half of the patients had their age of onset at 6-10 years. Bimodal peak in age of onset was observed；the first peak was around 6 and the second peak was around 10 years. There was no sex difference in bimodal age of onset. The most common initial symptom was eye blinking. More than 55% of patients reported eye blinking as their first symptom. The second common initial symptom was head turning and the third was vocal tic. The most common symptoms that patients reported on their first visit since onset were eye blinking(82.2%), head turning or nodding(57.9%), shoulder shrugging(52.7%) and forearm movement(32.6%). Of 157 cases, 101(64.3%) patients showed downward progression of symptoms, and 25(15.9%) showed upward progression of symptoms. Nineteen fathers(12%) of patients had a past history of obsessive-compulsive disorder(OCD). Seventeen fathers(10.6%) had a history of tic disorder. SSevenmothers(4.5%) had OCD, 4 mothers (2.5%) had tic disorder. One hundred and eighteen patients(75.1%) had comorbid hyperactivity, 95 patients(60.5%) had obsession, 55 patiens(35.0%) had self destructiveness, 46 patients(29.3%) had impulsivity, and 35 patients(22.3%) had enuresis. Age of onset had a significant positive correlation with age, duration, and the global severity of obsession；and a negative correlation with the severity of hyperactivity. Hyperactivity had a significant positive correlation with impulsivity, obsession-compulsion, enuresis, and self destructiveness. Obsession-compulsion had a significant positive correlation with hyperactivity, sleep problems, and self destructiveness. Conclusion：These data suggest that clinical characteristcs and behavioral comorbidity of patients with Tourette’ disorder in this study are similar to previous research findings in Korea and other contries. The younger the age of onset was, the more severe hyperactivity was, and the less severe obsession-compulsion was. And severity of hyperactivity had a positive correlation with the severity of obsession-compulsion, impulsivity, enuresis, and self destructiveness.

• Archives of design research
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• v.18 no.4 s.62
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• pp.15-24
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• 2005

The demand against the house space of the style which is various increases with to join in and the importance which the color does hold gradually is magnified and color meaning from house space is embossed, diversification the necessity of the color plan which hits to the social change which is turning out is recognized. From the research which it sees the importance recognition against the color plan which is must become accomplished variousfrom house space. It analyzes the color tendency of the apartment model house and it presents it does the guide line of house space color design $2001{\sim}2004$ It was sold in lots from the year Busan area in center, the acreage and the space(the wall/the ceiling, the furniture type, the window and door type and the floor type) it used 'The hue&tone 120 color system' and it grasped to the sincere analysis method and the color use present condition which leads a frequency analysis. When it sees the color analysis result of the research which it sees space especially the color plan period for a discrimination compared to the organic enemy the unity which considers a relationship the crisis which will the plan is become accomplished with the direction for, Magnification feeling or high class of the area it is that it shows the color tendency which is discriminated it was with equilibrium general classification.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.223-233
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• 2014

This study empirically analyzes the relationships among the road and traffic experts' personal characteristics, the driving behavior and factors being expected to have an effect on the satisfaction about roundabout operation. The factors are drawn and grouped through the principle component analysis to clarify driving environment satisfaction on roundabout operation. Each group is named as personal attribute, driving behavior attribute, and satisfaction. After the variables are refined by confirmatory factor analysis, satisfaction model is developed with personal attribute and driving behavior attributes as exogenous variables and roundabout driving awareness and emotion attributes as endogenous variables. As a result, driving satisfaction of roundabout operation is directly influenced by delay reduction, safety improvement, capacity increase, sight improvement, severity accident reduction, and bicycle convenience and indirectly gender, age, driving time, and driving experience. Law obeyance, driving concession, traffic sign obeyance, and interposition do not statistically shows significant on satisfaction. As a result of Analytical Hierarchy Process (AHP), the turning radius of geometry and the driving behavior are important elements for roundabout safety.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.1
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• pp.69-78
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• 2002

In order to examine the directional suitability of the axis direction of the fishing gear against the current, the experiments were carried out at the bamboo weir in Samchunpo water area from January, 2000 to September, 2001 The results of the study are as follows: In the experimental fishing gear constructed in the "V" shape, the range between two reference piles located at the entrance was 2.5m. The direction of bamboo weir′s axis was 355.5$^{\circ}$ The length of the left wing and those from the reference pile to the starting point of a curve were 106.0m, 7.5m, respectively. The length of the right wing and those from the reference pile to the starting point of a curve were 79.0m, 10.0m, respectively. Depths around the left and right stone wall that drove the steel pile were 5.0~6.5m and 6.5~9.5m, respectively. Also, depths on the bamboo weir′s axis and around the sack were 7.0~8.0m and about 8.0m, respectively. The maximum height of stone walls at the point of the left wing, the right wing and around the sack on the bamboo weir\` axis were 3.0m, 4.7m and 4.0m, respectively, Widths of stone walls at the point of both of the wings and around the sack on the bamboo weir\`s axis were 10.0~l4.0m, 22.0~25.0m, respectively. The averaging current direction on ebb tide was measured two times and it was 169.2$^{\circ}$ but the direction had about a 6.3$^{\circ}$ difference from the bamboo weirs axis. The maximum current speed appeared two to three hours later from the time of high tide and the current speed over 80.0cm/s lasted during about two Hours on the ebb tide In the case of a straight type wing In the bamboo weir, the eddy out of the left wing was comparatively big and the current on the right side from the bamboo weir′s axis had a tendency in turning to the right wing side. But in the case of a curve type wing, the eddy and tendency reduced significantly. It was thought that the experimental fishing gear was set suitably from the result of this simulation.