• Title/Summary/Keyword: Difference Set

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Korean E-commerce Platform's Dashboard Style Decision Support System

  • Yum, Kyeongmin;Park, Jae-Sang;Yoo, Byungjoon
    • 한국벤처창업학회:학술대회논문집
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    • 2021.11a
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    • pp.113-117
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    • 2021
  • Due to the recent COVID-19 pandemic, SMEs are forced to converge themselves into online business to cope with the rapidly changing business environment. However, due to various difficulties of becoming an online business, most SMEs choose to use services provided by the online sales platform. These platforms offer valuable support such as DSS in return for the high amount of commission fee. We analyze a novel data set from Naver Corporation's 'Smart Store' platform with the quasi-experimental method (propensity score matching technique combined with the difference in differences analysis) to analyze DSS usage and SME's performance empirically. Our results suggest that DSS usage leads to an increase in SME's sales performance in means of sales frequency and sales amount. Additionally, we have found weak support that DSS usage enables SMEs to attract customers better than those not using DSS.

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The View Character of Mountainscape of a City according to Visual Point Level - In a Case of Mt. Uam - (시가지내 산악경관의 시점 높이별 조망 특성 - 청주시 우암산을 대상으로 -)

  • Jeong, Jeong Seop;Gwon, Sang Jun;Jo, Tae Dong
    • Journal of Environmental Science International
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    • v.13 no.6
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    • pp.497-503
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    • 2004
  • In this research, we have performed a T-test to see how the relationship between dependent variable or visual point level and independent variable or visual quantity is in order to clear up the correlation between pattern of visual point and visual quantity by the constituents of a view from a different visual point level and the results are as follows: 1) In case of the character of Mt. Uam landscape of the city, Uamsan is set as a fixed point and about a direction of view(D), the north is a datum point from which the range of direction is distributed within 1800 westwardly and the visual range(R) is also within 2000m. An elevation is an average of 7.40 and the average story of the buildings is 3.85. Here the height of a story is about 4m so the average of the visual point difference is estimated at 15.4m. 2) The type of visual point is divided into the intersection group and the front of the highly used public buildings group. Double intersection types account for about 78.80%(52 spots) which forms a majority part of LCP. 3) The analysis of the difference of visual point level divided by eye level and that of the top of the buildings has been proved that there's a sharp difference resulted from t-test at 1 % significant level. The significant difference of elevation from height difference(l5.93m), however, has not been shown. 4) From the result of T-test about visual quantity by the elements of a view from a different visual point level, the visual quantity of mountain(VQM), sky(VQS), ground(VQG) is significant at about 1% each and that of building(VQB) is at about 5%. The difference in visual quantity of a mountain by the visual point level is at about 4% which can meet a marginal level of LCP necessary for evaluation of mountainscape.

Comparison of Body Composition, Physical Fitness, Isokinetic Strength between a major in EMT Students and a major in Physical Education Students (응급구조 전공과 체육 전공학생의 신체구성, 체력 및 슬관절 등속성 근기능 비교 연구 - 대전·충남을 중심으로 -)

  • Cho, Byung-Jun;Kim, Hak-Soo
    • The Korean Journal of Emergency Medical Services
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    • v.9 no.2
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    • pp.129-136
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    • 2005
  • The purpose of this study was to compare the level of physical fitness and isokinetic strength, between EMT student and physical education students. Nine a major in EMT student volunteers, and nine a major in physical education student volunteers participated in that study as subjects. The basic physical body composition, fitness and isokinetic strength were measured. The data obtained in the study was analyzed by SPSS PC+ for window version 10.0. The difference in the mean of each variable between the two groups was analyzed by using the independent t-test and the significance level for all analysis was set at <.05. The results were as follows ; 1. There was a significant difference in the basic physical fitness between the two groups with the exception flexibility. The difference showed the statistical significance on back strength, balance and power in physical education students. 2. There were significant difference in body composition between the two groups with the exception of lean body fat. The difference showed the statistical significance on body fat%, body fat mass in the physical education students. 3. There was significant defference in the isokinetic strength between the two group. The difference showed the statistical significance on peak torque, peak torque B/W%. It was concluded that the physical education students may not have an effect of flexibility; however, back strength, balance, power, body composition, isokinetic strength, could be enhanced due to the long-term period of training. Based on the findings of this study, the regular participation of regular exercise help the untrained men achieve health-related fitness.

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A Study on the Effect of the Difference at Design Pattern on the Characteristics of Observation (디자인유형의 차이가 주시특성에 끼치는 영향에 관한 연구)

  • Kim, Jong-Ha;Park, Sun-Myung
    • Korean Institute of Interior Design Journal
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    • v.22 no.1
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    • pp.174-182
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    • 2013
  • This study divided the observation area in an indoor space for area setup to analyse the effect of the difference of design types on the characteristics of observation with the observed time of each area as objects. Though it is thought that the difference of design patterns may be influenced by the factors and material composing the space, no existing approaches have had any quantitatively measuring method. Eye-tracking could be efficiently utilized for observation analysis from the viewpoint of dating observation behavior. The followings are the results of analysing the observation characteristics depending on design pattern. First, 5 observing areas were set up according to concentration of observation time in order for the concentration by area to be examined and the factors of design having effect on the difference of observation patterns by design type could be analysed. Second, as a whole, the observation of modern types showed high observation characteristics. When the difference of observation characteristics by pattern was examined by difference at observation frequency, the observation frequency defined to be more than 50% was seen to be almost same from Area I to III and to get higher from Area IV, and that defined to be 30% was high at Areas III and IV. In Area V, it was very high at natural. Third, that of Area II is no more than 8.2% but had the most observation time. As for observation characteristics, the horizontal observation of the central part was the highest and had more observation frequency at modern type that at natural one. These observation characteristics by area enabled to analyse the observation tendency depending on design characters at relevant area. Fourth, the design factors composing natural type were found to bring more attention when the area showed higher concentration at natural type than at modern one. And the analysis of design factors could make it to be confirmed that the quality of material and background factors in addition to design factors in the area had more effect on sight concentration.

Effects of the Air-Pressure Asymmetry of Wheelchair Tires on Pelvic Height, Gluteal Pressure, and Muscular Recruitment Pattern in Asymptomatic Participants (타이어 공기압 비대칭이 무증상 대상자의 골반높이, 둔부압력, 근동원패턴에 미치는 영향)

  • Park, Sang-Yeong;Park, Se-Yeon
    • PNF and Movement
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    • v.19 no.3
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    • pp.375-382
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    • 2021
  • Purpose: The objectives of the present study were to investigate the disadvantages of tire pressure asymmetry of a wheelchair tire and recommend the criterion for appropriate tire pressure without generating negative changes in the musculoskeletal system in asymptomatic participants. Methods: Fourteen asymptomatic participants were asked to sit in pressure-controlled wheelchairs and perform desk work for 20 minutes in each tire condition. The asymmetry of the tire conditions was set as 0% difference, 25% difference, and 50% difference from the recommended pressure. The pelvic alignment and muscular recruitment represented as a flexion-relaxation ratio (FRR) were measured at pre-test, and after each condition of desk work. The displacement of the center of pressure (COP) was measured during the desk work. Results: The tire air pressure condition significantly affected the FRR and COP (P < 0.05). Both sides of the FRR values were significantly higher under the symmetrical tire conditions (0% difference) and pre-test, compared with the asymmetrical tire condition of 50% difference (P < 0.05). The mediolateral COP displacement of the asymmetrical tire conditions (25% and 50% difference) was significantly higher than that of the symmetrical tire conditions (0%) (P < 0.05). Conclusion: Asymmetrical tire conditions could cause changes in the muscle recruitment pattern of the erector spine and mediolateral COP displacement. Tire pressure asymmetry higher than 50% could be a risk factor for prevalence of back pain, so this level of asymmetry in tire pressures should be cautioned against for wheelchair users.

Effect of Vibratory Stimulation on Recovery of Muscle function from Delayed Onset Muscle Soreness

  • Koh, Hyung-Woo;Kim, Cheol-Yong;Kim, Gye-Yoep;Kim, Kyung-Yoon;Kim, Soo-Geun;Lee, Hong-Gyun
    • Korean Journal of Exercise Nutrition
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    • v.16 no.1
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    • pp.43-50
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    • 2012
  • This study was designed to investigate the effect of vibratory stimulation on recovery of muscle function from delayed onset muscle soreness (DOMS). Volunteers performed 3 set of 70 % maximal voluntary eccentric muscle contraction and induced DOMS. volunteers were allocated to one of three treatment group after DOMS : group I (control), group II (ultrasound), group III (vibration). Maximal Voluntary Isometric Contraction (MVIC), Visual Analog Scale (VAS), Range Of Motion (ROM), Root Mean Square (RMS), Median frequency (MDF), Blood Serum Creatine Kinase (CK), Lactic dehydrogenase (LDH) were recorded at baseline, and 24, 48, 72 hours post-exercise. In MVIC measurement, there was a statistically significant difference in group III compared to group I (p < .05). In VAS measurements, there were a statistically significant difference in group II and III compared to group I (p < .05). In ROM measurement, there was a statistically difference in group II and III compared to group I (p < .05). In Muscle Volume with Ultrasonography measurement, there was no statistically significant difference in any groups (p > .05). In RMS and MDF measurement, there were a statistically significant difference in group II and III compared to group I (p < .05). In Blood samples of CK and LDH measurements, There were no statistically significant difference in any groups (p > .05). From the above result, Vibratory stimulation had a positive effect on recovery of muscle function from delayed onset muscle soreness. Further studies should be undertaken to ascertain the more effectiveness of vibratory stimulation and may be a promising treatment modality.

Difference of muscle activity and muscle contraction onset time of the trunk and lower extremity according to object weights and leg length discrepancy during lifting tasks (물건 들기 시 다리길이 차이 유무와 물건 무게에 따른 몸통과 다리의 근활성도와 근수축 개시시간 차이)

  • Hyeon Nam Ryu;Sung Jun Han;Jin Tae Han
    • Journal of Korean Physical Therapy Science
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    • v.31 no.2
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    • pp.30-40
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    • 2024
  • Background: The purpose of this study is to identify the difference in muscle activity and muscle contraction onset time according to a LLD and object weight When subjects performed a lifting task. Design: Repeated measure design Methods: 15 male adults participated in this study. When subjects performed a lifting task, we measured a difference of muscle activity and muscle contraction onset time in the rectus abdominis(RA), the erector spinae(ES), and the rectus femoris(RF) between both legs using the surface electromyogram (Telemyo DTS, Noraxon Inc., USA). When subjects performed a lifting task, the weight of the object was set to 0% kg, 10% kg, and 20% kg of the subject's body weight, excluding the weight of the box. Results: The difference in muscle activity in the RA, the ES, and the RF between both legs when lifting an object was larger in LLD condition than in non-LLD condition(p<0.05). In all of muscles, the difference of contraction onset time was generally increased as the object's weight increased. Specially, the difference in muscle contraction onset time in the RA, the ES between both legs was larger in the LLD condition than in the non-LLD condition(p<0.05). Conclusion: This study suggests that LLD affects the muscle activity and muscle contraction onset time during lifting objects. It can be used as data to prevent joint damage and muscle due to the LLD during work and movements of daily living.

The Resident Space Object Detection Method Based on the Connection between the Fourier Domain Image of the Video Data Difference Frame and the Orbital Velocity Projection

  • Vasilina Baranova;Alexander Spiridonov;Dmitrii Ushakov;Vladimir Saetchnikov
    • Journal of Astronomy and Space Sciences
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    • v.41 no.3
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    • pp.159-170
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    • 2024
  • A method for resident space object detection in video stream processing using a set of matched filters has been proposed. Matched filters are constructed based on the connection between the Fourier spectrum shape of the difference frame and the magnitude of the linear velocity projection onto the observation plane. Experimental data were obtained using the mobile optical surveillance system for low-orbit space objects. The detection problem in testing mode was solved for raw video data with intensity signals from three satellites: KORONAS-FOTON, CUSAT 2/FALCON 9, and GENESIS-1. Difference frames of video data with the AQUA satellite pass were used to construct matched filters. The satellites were automatically detected at points where the difference in the value of their linear velocity projection and the reference satellite was close in value. An initial approximation of the satellites slant range vector and position vector has been obtained based on the values of linear velocity projection onto the frame plane. It has been established that the difference in the inclination angle between the detected satellite intensity signal Fourier image and the reference satellite mask corresponds to the difference in the inclinations of these objects. The proposed method allows for detecting and estimating the initial approximation of the slant range and position vector of artificial and natural space objects, such as satellites, debris, and asteroids.

THE p-LAPLACIAN OPERATORS WITH POTENTIAL TERMS

  • Chung, Soon-Yeong;Lee, Hee-Soo
    • Communications of the Korean Mathematical Society
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    • v.26 no.4
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    • pp.591-601
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    • 2011
  • In this paper, we deal with the discrete p-Laplacian operators with a potential term having the smallest nonnegative eigenvalue. Such operators are classified as its smallest eigenvalue is positive or zero. We discuss differences between them such as an existence of solutions of p-Laplacian equations on networks and properties of the energy functional. Also, we give some examples of Poisson equations which suggest a difference between linear types and nonlinear types. Finally, we study characteristics of the set of a potential those involving operator has the smallest positive eigenvalue.

Eye and hand movement by experienced and novice workers in hazard machinery operation (위험 기계작업에서 숙련자와 초보자의 눈과 손 움직임에 대한 연구)

  • 박경수;김유창
    • Proceedings of the ESK Conference
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    • 1995.10a
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    • pp.101-108
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    • 1995
  • This paper presents an experiment which examines eye movement characteristics of novice and experienced workers in the press operation. Signficant difference between the novice and the experienced workers was observed in eye fixation time, eye movement patterns, hand duration time, and hand movement time. The results could be used to set up a guide to train the novice workers and to determine how long the novice should be trained.

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