• BMB Reports
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• v.48 no.6
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• pp.324-329
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• 2015

CopA3 is a homodimeric ${\alpha}$-helical peptide derived from coprisin which is a defensin-like antimicrobial peptide that was identified from the dung beetle, Copris tripartitus. CopA3 has been reported to have anticancer activity against leukemia cancer cells. In the present study, we investigated the anticancer activity of CopA3 in human gastric cancer cells. CopA3 reduced cell viability and it was cytotoxic to gastric cancer cells in the MTS and LDH release assay, respectively. CopA3 was shown to induce necrotic cell death of the gastric cancer cells by flow cytometric analysis and acridine orange/ethidium bromide staining. CopA3-induced cell death was mediated by specific interactions with phosphatidylserine, a membrane component of cancer cells. Taken together, these data indicated that CopA3 mainly caused necrosis of gastric cancer cells, probably through interactions with phosphatidylserine, which suggests the potential utility of CopA3 as a cancer therapeutic. [BMB Reports 2015; 48(6): 324-329]

• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.395-409
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• 2017

Objective: The purpose of this study was to optimize the number and positions of foot pressure sensors using the reliability analysis of the center of pressure (COP) in smart shoes. Background: Foot pressure can be different according to foot region, and it is important which region of the foot pressure needs to be measured. Method: Thirty adults (age: $20.5{\pm}1.8years$, body weight: $71.4{\pm}6.5kg$, height: $1.76{\pm}0.04m$) participated in this study. The foot pressure data were collected using the insole of Pedar-X system (Novel GmbH, USA) with a sampling frequency of 100Hz during 1.3m/s speed walking on the treadmill (Instrumented treadmill, Bertec, USA). The intraclass correlation coefficients (ICC) were calculated between the COP positions using 4, 5, 6, 7, 8, and 99 sensors, while one-way repeated measure ANOVA was performed between the standard deviation (SD) of the COP positions. Results: The medio-lateral (M/L) COP position using 99 sensors was positively correlated with the M/L COP positions using 6, 7, and 8 sensors; however, it was not correlated with the M/L COP positions using 4 and 5 sensors during landing phase (1~4%) (p<.05). The antero-posterior (A/P) COP position using 99 sensors was positively correlated with the A/P COP positions using 4, 5, 6, 7, and 8 sensors (p<.05). The SD of the COP position using 99 sensors was smaller than the SD of the M/L COP positions using 4, 5, 6, 7, and 8 sensors (p<.05). Conclusion: Based on our findings, it is desirable to arrange at least 6 sensors in smart shoes. Application: The study of optimizing the number and positions of foot pressure sensors would contribute to developing more effective smart shoes using foot pressure technology.

• Journal of the Korean Institute of Gas
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• v.16 no.5
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• pp.66-75
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• 2012

Polyurethane foams were synthesized by substituting a portion of petroleum base polyether polyol with castor oil-derived polyol(COP). Contact angle tester and surface tensionmeter were used to examine the compatibility of petroleum base polyether polyol and COP. To investigate the optimum content of COP and surfactant, the content of COP has been changed from 0 wt% to 80 wt%. From the results of polyurethane foams synthesized by surfactant L-580K, DC-5950 and BF-2470, the best mechanical properties was observed when the content of COP was 30wt% and surfactant BF-2470.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.786-793
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• 2020

The purpose of this study is to analysis the horizontal distance of COM and COP and the movement patterns of COM and COP during the badminton high-clear of woman middle school student. The select variables used in the statistical analyses(independent sample T-test) were the horizontal distance of COM and COP at (E4), and the maximum COM displacement of the back-, forward-, whole-swing phases between expert and novice groups. Based on the results in this study, it was concluded that: First, expert group showed the shorter horizontal distance between COM and COP in anteroposterior axis (X-axis) at Event 4 compared to the novice group. Second, expert group dominantly used COM vertical movement while novice group actively used COM horizontal movement during the badminton high-clear stroke.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.1
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• pp.15-24
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• 2010

Purpose : The purpose of this study was to investigate the effect of loading position on plantar center of pressure(COP) displacement when carrying a schoolbag during walking. Methods : Forty-four normal subjects were randomly assigned to five groups according to the method of carrying a schoolbag. The carrying a schoolbag methods were classified into five conditions: no bag (condition 1), a backpack (condition 2), a shoulder bag (condition 3), a cross bag (condition 4), a one-hand bag (condition 5). COP displacement such as anteroposterior distance and mediolateral distance of COP were measured with F-scan system. The repeated one-way analysis of variance (ANOVA) and independent t-test were used to confirm the statistical significance. Results : In the comparison of parameters of COP displacement between conditions, anteroposterior distance and mediolateral distance in the left foot and mediolateral distance in the right foot were not significantly different(p>.05), but anteroposterior diatance in the right foot was significantly different(p>.05). Between left and right foot, at condition 1 and 5 the mediolateral distance of COP was significantly different(p<.05) but anteroposterior distance at condition 1 and 5, anteroposterior distance and mediolateral distance of COP at condition 2, 3 and 4 were not significantly different(p>.05). Conclusion : These findings showed that the various loading position by five types of carrying a schoolbag didn't have influence significantly on COP displacement on during walking because of mechanism of postural adaption.

• Physical Therapy Korea
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• v.28 no.1
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• pp.77-83
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• 2021

Background: Although symmetry of spatio-temporal parameter and center of pressure (COP) shift during walking is associated with knee adduction moment, research on clinical association with knee osteoarthritis (OA)-related knee pain and functional scores is lacking. Objects: The aims were 1) to compare symmetry of gait parameters and COP-shift in patients with unilateral knee OA and pain and matched controls, and 2) to investigate the relationship between symmetry of gait parameters and COP-shift, and clinical measures. Methods: Female subjects (n = 16) had with unilateral radiological knee OA and pain. Healthy controls (n = 15) were age-matched to OA group. Symmetry of foot rotation, step length, stance and swing phase, lateral symmetry of COP and anterior/posterior symmetry of COP during walking was assessed. To assess the clinical variables, pain intensity, pain duration and function using Knee Osteoarthritis Outcome Survey (KOOS) subscales were collected. We compared symmetry between groups using Mann-Whitney U-test or independent t-test. Relationships between clinical measures and symmetry index measured using Spearman's correlation test. Statistical significance was set at α = 0.05. Results: Knee OA group showed significantly greater values of only lateral symmetry of COP (p < 0.01) than healthy group. Values of lateral symmetry of COP had moderate or strong correlation significantly with the intensity of knee pain, pain duration, and scores of all KOOS subscales (p < 0.01). Conclusion: Patients with unilateral knee OA and pain showed more asymmetry of lateral COP-shift during walking compared with matched healthy controls. In addition, larger asymmetry of lateral COP-shift has the moderate or strong association with worse of knee pain, worse in KOOS scores and longer duration of knee pain. Asymmetry of lateral COP-shift during walking may be one of the characteristics of unilateral knee OA as the compensatory strategy response to unilateral OA of the knee.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.193-193
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• 2011

현재까지 대부분의 지열원 열펌프 시스템에 관한 연구는 열펌프 유닛과 지중열교환기에 대해 개별적으로 수행되었으며, 열펌프 유닛과 지중열교환기 설계 및 최적화의 공통변수인 지중순환수 유량에 따른 시스템 전체에 대한 연구성과는 매우 미미한 실정이다. 본 연구에서는 현재 국내에서 인증되어 보급되고 있는 물매물 지열원 열펌프 유닛의 성능 자료를 분석하고, 지중순환수 유량 변화에 따른 물대물 열펌프 유닛의 성능 실험 및 지중열교환기 형상에 관한 설계 및 분석을 수행하여 지열원 열펌프 시스템 최적화에 관한 기반 기술 확보하고자 하였다. 현재 국내의 물대물 지열원 열펌프 유닛의 냉방 및 난방 조건에서의 최소 인증 COP는 각각 4.1과 3.45이다. 다양한 용량 및 성능을 갖는 국내 인증 물대물 지열원 열펌프 유닛에 대한 정량적 성능 분석을 위하여 3.5kW(1RT) 용량당의 지중순환수 유량과 COP를 고찰하였다. 냉방운전시 3.5kW 단위 용량당 열펌프 유닛의 지중순환수 유량은 10.73에서 18.52LPM을 나타냈으며, 난방운전에는 10.41에서 18.16LPM을 나타냈다. 이때, 냉방 COP는 4.1에서 5.4의 값을 나타냈으며, 난방 COP는 각각 3.5에서 4.2를 나타냈다. 인증 열펌프 유닛에서 지중순환수 유량과 열펌프 유닛의 냉난방 성능은 일정한 경향성을 나타내지 않았다. 지중순환수 유량에 따른 지열원 열펌프 유닛과 시스템의 성능을 정량적으로 분석하고자 지중순환수 유량 변화에 따른 물대물 지열원 열펌프 유닛 성능 실험을 수행하고 이를 기반으로 지중열교환기를 설계 및 분석하였다. 냉난방 각 운전모드에서 ISO 13256-2 규격과 NRGT 101 규격을 기준으로 지중순환수와 부하측 유량 6LPM 에서 36LPM 사이에서 변화시키며 성능 실험을 수행하였다. 냉방 및 난방모드 모두 유량이 증가함에 따라 열펌프 유닛 COP가 증가하였으나, 유량 증가에 따른 열펌프 유닛 COP 증가율은 감소하였다. 지중순환수 유량이 18LPM 이상에서는 COP 상승폭은 미소하였다. 기존문헌의 부하 산정자료와 열펌프 유닛 실험 성능 데이터를 이용하여 지식경제부 고시 2009-332호에 준하여 수직밀폐형 지중열교환기를 설계하고 순환펌프 소요동력을 이용하여 시스템 COP를 분석하였다. 지중열교환기 설계 시 국내에서 가장 많이 사용되고 있는 상용지중열교환기 설계프로그램인 GLD 프로그램을 사용하였다. 지중순환수와 부하측 2차 유체 유량 증가 시에 열펌프 유닛 COP 증가율 대비 시스템 COP 증가율은 감소하였으며, 난방모드에서는 일정 유량 이상에서는 열펌프 유닛 COP는 증가하였으나, 시스템 COP는 감소하였다. 또한, 지중순환수 유량 증가에 따라 지중열교환기 길이가 증가하였으며, 냉난방시의 지중열교환기 길이차이가 증가하였다. 지열원 열펌프 시스템의 고효율화 및 시공비 절감을 통한 경제성 확보를 위해서는 지열원 열펌프 유닛 성능과 지중열교환기 형상 공통 변수인 지중순환수 유량을 함께 고려하여 시스템을 설계하여야한다.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.485-491
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• 2014

In this paper, it is proposed that the effects of simulator sickness due to scene movement in ship handling simulator can be measured by using center of pressure (COP) and a simulator sickness questionnaire (SSQ). For experiments of simulator sickness, twelve participants are exposed to scenes movement from ship handling simulator according to three steps of sea states. During experiments, COPs for subjects are measured by force plate. After exposure to scenes movement, subjects describe their sickness symptoms by answering the SSQ. Throughput analysing the results of scene movement, SSQ, and COP, the relation between the simulator sickness and COP is investigated. It is suggested that formulations for SSQ score and COP with respect to sea state are obtained by the curve fitting technique, and the longitudinal COP can be used for measuring the simulator sickness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.393-401
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• 2021

This study derives essential information elements that should be shared in the situation board by utilizing the concept of common operating picture (COP). The COP's concept and actual overseas cases were confirmed, and COP information elements that should be considered for disaster situations were redefined. The COP disaster response information elements were derived by analyzing the standard manual for disaster response and daily situation reports issued in Korea. The information elements were divided into four stages (①Report reception and recognition stages, ②Situation propagation and reporting stages, ③Emergency equipment operation stages, ④Recovery and recovery stages), centered on storm and flood damage. Further analysis of the detailed information elements was conducted to derive the information elements that must be shared in the context board. The information is shared along with spatial and geographical characteristics due to the characteristics of the COP, providing complex information to decisionmakers and officials, enabling diverse access to disaster situations. Furthermore, it is expected that disaster response will be more efficient by sharing the information in common.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1211-1214
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• 2004

High-heeled women have been identified with balance control problems. The purposes of this study were to objectively quantify the displacements and velocities of center-of-pressure (COP) of body during waist pulling and to compare the differences between barefooted and high-heeled situations. We used a waist pulling system which has three different magnitudes to sway the subjects. We found that the kinematic information of barefooted and high-heeled women's COP is very important in understanding the mechanism of postural balance control of women in every-day life. In the high-heeled's case, the displacement of COP increases in 200％ as against bare footed. Also the velocity variation of COP grows three times than the bare footed. COP analysis in postural balance study of high-heeled women is also considered useful in development of the safety systems that prevent high-heeled women from falling