The Recongnition about Food Waste Treatment at Yongin Area

Jeong-Hyun Kim,HeeJoo Kang,KyungTae Kim,HyunSoo Kim,SeongHee Hwang,YongChul Kim,PanGyi Kim 한국환경보건학회 2004 한국환경보건학회지 Vol.30 No.4

Stereoselective Synthesis and Osteogenic Activity of Subglutinols A and B

Kim, Hyoungsu,Baker, Joseph B.,Lee, Su-Ui,Park, Yongho,Bolduc, Kyle L.,Park, Hyung-Bae,Dickens, Marina G.,Lee, Dong-Sup,Kim, Yongchul,Kim, Seong Hwan,Hong, Jiyong American Chemical Society 2009 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.131 No.9

Movement Analysis of Elderly People during Ingress/Egress from Different Seat Heights

Yongchul Kim 대한인간공학회 2011 大韓人間工學會誌 Vol.30 No.5

Objective: The aim of this study was to investigate the influence of seat heights for optimizing the ingress/egress performance in the elderly people. Background: Recently elderly users have been increasing in number and the ease of ingress/egress of the vehicle becomes an important issue. Method: Seven elderly subjects participated in this study(age: 71.7±3.6yr, height: 167.7±5.4㎝, weight: 68.1±11.5㎏). Each subject performed the sitting and rising task from comfortable seated position on the chair under the following conditions: (1) with a lumbar support and (2) without a lumbar support. We measured EMG activities of seven muscles(tibialis anterior, soleus, gastrocnemius, vastus lateralis, rectus femoris, biceps femoris and erector supinae) and ranges of motion in lower limb during sitting and standing from three different heights (400㎜, 500㎜ and 600㎜ from ground) of slide-up seat. Results: Muscle activities and angular movements of hip and knee joints during standing-up and sitting-down with a high seat height(600㎜) were reduced mean 30.4% in extensor muscles, 57.11% in flexor muscle, 18.74% in erector muscle and 31.0% in joints compared with a low seat height(400㎜). Conclusion: Muscle activities and joint movements in hip and knee were reduced when rising/sitting from a high seat height(600㎜) compared with a low seat height(400㎜). Application: This study can be used to design vehicle that are easy to get in and out of by older peoples with or without impairments.

Effects of taper and set-back on wind force and wind-induced response of tall buildings

Kim, Yongchul,Kanda, Jun Techno-Press 2010 Wind and Structures, An International Journal (WAS Vol.13 No.6

Advances in structural materials and construction methods have resulted in flexible and light tall buildings, making an assessment of structural safety during strong wind and serviceability/habitability during comparable medium/weak wind important design criteria. So far, lots of studies on suppressing the wind-induced responses have been carried out for tall buildings with aerodynamic modification. Most of the studies on aerodynamic modification have forced on the corner modification, while the studies on taper and set-back are limited. Changes of sectional shape through taper and set-back can modify the flow pattern around the models, encouraging more 3-dimensionalities, which results in reducing the wind-induced excitations. This paper discusses the characteristics of overturning moments and wind-induced responses of the tall buildings with height variations. The reduction of mean along-wind and fluctuating across-wind overturning moments are apparent in the suburban area than in urban area. A series of the response analyses, the rms displacement responses of the tall buildings with height variations are reduced greatly, while the rms acceleration responses are not necessarily reduced, showing dependences on wind direction.

The movement analysis of caregivers for transferring of a disabled person from wheelchair to car seat

Yongchul Kim,Younghyun Kim,Youngseon Yang,Woochul Park,KunminRhee 한국재활복지공학회 2008 한국재활복지공학회 학술대회논문집 Vol.2008 No.11

The aim of this study was to examine the influence of seat height on the movement of caregiver for transferring of a disabled person from wheelchair to car seat. Five female volunteers served as caregivers; two persons with disabilities and one health volunteer served as passive disabled person. To analyze the movement of a caregiver, we measured the activities of six muscles with surface electrodes and joint angle responses of the hip and knee with electrical goniometers. The caregivers performed transferring task at three different seat heights (400, 500 and 600mm from the floor) in order to investigate the effects of a car seat on transferring movement of a people with disability. From the experimental results, when caregivers were putting a disabled person down a seat, the hip and knee joint angles were decreased 31.9% and 24.7 % in 600mm seat height than 400mm seat height, respectively. The integrated EMG activity of erector spinae was decreased 16.3% in 600mm seat height, compared with 500mm seat height. However, the integrated EMG activity of rectus femoris for lower limb in 600mm seat height was increased 33.3% than 500mm seat height.

Identification of Flexion Withdrawal Reflex Using Linear Model in Spinal Cord Injury

Yongchul Kim,Youngil Youm 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.8

The aim of this study was to identify the characteristics of the flexion withdrawal reflex modulated by the hip angle and hip movement in spinal cord injury (SCI). The influence of the hip position and passive movement were tested in 6 subjects with chronic SCI. Each subject placed in a supine position and lower leg was fixed with the knee at 5~45 degree flexion and the ankle at 25~40 degree plantar flexion. A train of 10 stimulus pulses were applied at 200 ㎐ to the skin of the medial arch to trigger flexion reflexes. From results of the regression analysis, static properties of normalized muscle activation of flexor muscles have the linear relationship with respect to hip angle (P<0.05). In order to verify the neural contribution of flexion reflex, we compared the static and dynamic gains of estimated muscle activations with measured EMG of ankle flexor muscle. Form this study, we postulate that the torque and muscle response of flexion withdrawal reflex have linear relationship with hip angle and angular velocity.

Throughput and Fairness Analysis of Channel-hopping Scheme under Smart Jammer Attacks in IEEE 802.11 WLANs

Yongchul Kim 한국통신학회 2014 한국통신학회 학술대회논문집 Vol.2014 No.6

ON THE STUDY OF BAYESIAN RELATIVE ERROR PREDICTION

KIM, Yongchul 용인대학교 대학원 2005 International Symposium on HUMAN & CULTURE Vol.- No.-

A condition often imposed on estimated models is that estimates and predictions have a small relative error. Usually, however, the relative error criterion is not used in the estimation process, but only to evaluate a model estimated by other model. In this paper we suggest Bayes relative error loss which gives better results in prediction.

냉난방 성능향상을 위한 인테이크 도어 제어 연구

김용철(Yongchul Kim),성낙섭(Naksup Sung),박동규(Dongkyou Park),조후택(Hootaek Cho) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

Recently, the quick heating performance is the big issue in the vehicle because engine performance is high. So car makers adapted the additional heating devices (ex. PTC heater). As quick cabin cooling performance is recorded in the IQS, it is an important issue, too. In this study, the HVAC intake door control is studied for quick heating and cooling performance. In case of the heating performance, it improves 4.0℃ at -20℃ ambient after 20 minutes. And in case of cooling performance, it improves 1.5℃ at 35℃ ambient after 10 minutes. In addition, intake door control system brings on the cost reduction about 200 won because the flab door is eliminated. In present, intake door control system is adapted all HKMC new developing car.

Driving Performance of Adaptive Driving Controls using Drive-by-Wire Technology for People with Disabilities

Younghyun Kim,Yongchul Kim 대한인간공학회 2016 大韓人間工學會誌 Vol.35 No.1

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.