• 한국정보시스템학회지:정보시스템연구
• /
• 제28권1호
• /
• pp.73-96
• /
• 2019

Purpose The purpose of this study is to examine the effect of communication-structure characteristics on performance in online collaboration using the data from Github, one of representative open source software development platforms. We analyze the impact of in-degree/out-degree centralization and reciprocity of communication network on collaboration performance in each project. In addition, we investigate the moderating effect of owner types, an individual developer or an organization. Design/methodology/approach We collect the data of 838 Github projects, and conduct social network analysis for measuring in-degree/out-degree centralization and reciprocity as independent variables. With these variables, hierarchical regression analysis is employed on the relationship between the characteristics of communication structure and collaborative performance. Findings Our results show that for the project owned by an organization, the centralized structure of communication is not associated with the collaboration performance. In addition, the reciprocity is positively related to the collaboration performance. On the other hand, for the project owned by an individual developer, the centralized structure of communication is positively related to the performance, and the reciprocity does not show the positive relationship on the performance.

• Bulletin of the Korean Chemical Society
• /
• 제29권3호
• /
• pp.555-561
• /
• 2008

In air stripping of ammonia from the aqueous solution, a new removal model was presented considering the equilibrium principles for the ammonia in aqueous solution and between the aqueous and air phase. The effects of pH, temperature and airflow rate on the ammonia removal were evaluated with the model. In addition, the saturation degree of ammonia in air was defined and used to evaluate the effect of each experimental factor on the removal rate. As pH (8.9 to 11.9) or temperature (20 to 50 oC) was increased, the overall removal rate constants in all cases were appeared to be increased. Our presented model shows that the degrees of saturation were about the same (0.45) in all cases when the airflow condition remains the same. This result indicates that the effect of pH and temperature were directly taken into consideration in the model equation. As the airflow increases, the overall removal rate constants were increased in all cases as expected. However, the saturation degree was exponentially decreased with increasing the airflow rate in the air phase (or above-surface) aeration. In the subsurface aeration the saturation degree remains a constant value of 0.65 even though the airflow rate was increased. These results indicate that the degree of saturation is affected mainly by the turbulence of the aqueous solution and remains the same above a certain airflow rate.

• East Asian Economic Review
• /
• 제25권2호
• /
• pp.175-203
• /
• 2021

Over the past decades, financial markets have been integrated across countries while income inequality has increased in most countries. This paper studies the effect of financial market integration on income inequality and investigates whether this effect varies with the degree of financial market development. We find empirical evidence that financial market integration and financial market development interact to change income inequality. Specifically, the effect of financial market integration on income inequality is nonlinear, and the degree of financial market development plays an important role. Opening financial markets worsens income inequality in the countries holding the underdeveloped state of financial markets, however, the effect of capital account openness on income inequality is statistically insignificant in the countries with developed financial markets.

• The Journal of Korean Physical Therapy
• /
• 제7권1호
• /
• pp.43-49
• /
• 1995

The purpose of this study were to determine the effect of testing posture and elbow position on grip strength. Two hundred college students 100 males and 100 females aged 18 to 28 years, participated in the study. A Grip-Strength Dynamometer was used to measure the grip strength in two testing posture(sitting and standin) and four elbow position$(0^{\circ},\;45^{\circ},\;90^{\circ}\;and\;135^{\circ}\;flexion)$ correlations and t-test was used to determine any significant difference in grip strength between the testing posture and the elbow position. The results were as follows : 1. The grip strength was affected by testing pasture and flexion degree of elbow. 2. The grip strength was stronger in the standing than sitting in subjects 3. The grip strength decreased according to elbow flexion increase in subjects. 4. The higher grip strength gained in the standing with the elbow 0 flexion. 5. The grip strength by elbow flexion degree showed significant difference at sitting and standing posture. The grip strength was significant differenced by testing position at same elbow flexion degree.

• Imaging Science in Dentistry
• /
• 제35권2호
• /
• pp.83-86
• /
• 2005

Purpose : To evaluate the effect of deviation of mandibular positioning, by changing the mandibular plane inclination, on the measured height and width of mandible in spiral conventional tomography. Materials and Methods : By means of the Scanora multifunctional unit, cross-sectional tomograms were taken from two human dried mandibles at the mandibular angulations: -15 degree, -10 degree, -5 degree, and 0 degree. Twenty-eight sites in two dried mandibles were imaged. One examiner measured the bone heights and widths at selected sites on the images and the actual bone heights were recorded. Results : The bone heights at the four mandibular inclinations overestimated real bone heights and the mean difference between actual heights and image heights on 0 degrees was the smallest (P<0.01). The bone widths on -15 degrees were narrowest and there were significant differences between bone widths measured at the four mandibular inclinations (P<0.001). We found statistically significant differences between both bone heights and widths as measured according to the mandibular plane angle for the posterior region (P<0.01). Conclusion : The use of different mandibular positioning may result in discrepancies in heights and widths when measured from the cross-sectional tomographic images. It is suggested that the mandibular positioning may play a significant role in the measurement of mandibular heights and widths.

• 한국운동역학회지
• /
• 제13권2호
• /
• pp.89-100
• /
• 2003

In this research was to analyze 3-D kinematics variables for handspring of basic motion in the heavy gymnastics in order to investigate kinematical difference between expert and novice. Therefore, the purpose of this research was provide quantitative information, systematic provision, rules, establishment of basic skill for improving skill and teaching athletes. And in the research, results were as followings. 1. In the time variables, total time was that expert took 0.745sec and novice took 0.829sec, and as duration time of each event, expert was faster than novice in the all motion event except till second event of the preparation motion. 2. In the center of body variables, vertical direction variables, the displacement of body center hight was that expert showed 61.26% and novice showed 54.48% in the third event of all motion, also all event were showed expert was higher displacement than novice except first of event in preparatory stage. 3. In the angle displacement of main joint, the right direction was that expert showed 154.12degree and novice showed 174.85degree and the left direction was that expert showed 159.29degree and novice showed 171.46degree In the second event of main joint curved point at the same time hand was reached floor. In the angle displacement of knee joint in the third event of all motion, expert showed 155.25degree and novice showed 154.00degree In right, and expert showed 155.24degree and novice showed 154.55degree in left. In this result, both were same motion type. In the angle displacement of hip joint in the third event of the all motion, expert showed 142.80degree and novice showed 134.17degree in right, and expert showed 140.28degree and novice showed 144.94degree in left. In this result, motion pattern of expert was same both sides, but novice was different. According to the results, to increase efficiency of motion and aesthetic effect in the all motion, it should stretch displacement and height of body center and make similarly angle of right and left joint.

• KIEAE Journal
• /
• 제9권4호
• /
• pp.11-16
• /
• 2009

To act and respond to the climate changes and to bring about power-saving in buildings, the changes in the atmospheric data in Korea are recorded and assessed. For the two regions representative of Korea, the data obtained from HadCM3 and actual data are compared and analyzed so as to concretely evaluate and confirm the changes taking place in the cooling and heating degree days in Korea. For the past 40 years, from 1996 to 2005, the number of heating degree days was on the decline and in the two representative regions, between 1980's and 1990's, the number of decrease in the heating degree days had been quite large. The number of cooling degree days showed a trend of increase since the 1970's and just as in the case of heating degree days, the extent of increase was quite large between the 1980's and the 1990's. The results of comparison of the number of heating and cooling degree days, one obtained from the "Korea Meteorological Administration" and another from the HadCM3 data (E127.5,N37.5,E127.5,N35), which is one of the ways of predicting the climate, showed similar trends in the number of heating degree days in the Yeosu area. However, in the case of the number of heating degree days in Seoul and the number of cooling degree days both in Seoul and Yeosu, the differences in the number ranged from a minimum of 300 days to a maximum of 1500 days. This could be attributed to the grid points used in the HadCM3, the differences in the values of latitudes and longitudes of these two locations considered in this study, topographical differences, heat island effect caused by population density etc. and while using the HadCM3, these variables factors must be taken into consideration.

• 한국학교수학회논문집
• /
• 제19권3호
• /
• pp.217-238
• /
• 2016

본 연구에서는 중학교 2학년의 수학 학업성취도에 대한 교사와 부모의 성취압력과 수학 내재적 동기의 영향력과 조절효과를 검증하였다. 연구 결과, 수학 내재적 동기의 수준에 따라, 수학 내재적 동기가 높은 집단에서 교사의 성취압력은 수학 학업성취도에 부적인 영향을 미치는 반면, 수학 내재적 동기 중 하집단에서는 교사의 성취압력이 수학 학업성취도에 정적인 영향을 미치는 것으로 나타났다. 부모의 성취압력은 수학 내재적 동기가 높은 집단과 낮은 집단 모두 수학 학업성취도에 정적인 영향을 미치고, 특히 수학 내재적 동기가 중 상인집단이 하집단에 비해 수학 학업성취도에 더 큰 효과를 나타냈다. 이러한 연구 결과를 바탕으로 교사와 부모의 성취압력을 통해 수학 학업성취도를 높일 수 있는 방안이 논의되었으며, 후속 연구를 위한 연구의 제한점을 제시하였다.

• 공업화학
• /
• 제7권1호
• /
• pp.203-213
• /
• 1996

평형 추출장치를 사용하여 유기산의 물리추출과 반응추출에서 추출도에 미치는 추출제의 종류와 농도, 용매의 영향을 조사하였다. 사용된 유기산은 아크릴산과 메타크릴산이었고, 추출제로는 n-octylamine(OA)과 di-n-octylamine(DOA), tri-n-octylamine(TOA)및 tri-octylmetyl ammonium chloride(TOMAC ; Aliquat 336)을 사용하였다. 실험결과 반응추출에서 추출도는 물리추출의 경우보다 2~9배 정도 증가 되었으며, 유기산의 추출도에 미치는 추출제의 영향은 OA, TOMAC, DOA 및 TOA의 순서로 추출도가 증가하였으며, 또한 추출제의 농도가 증가할수록 추출도가 증가하였다. 용매의 영향은 종래의 용매의 유전상수보다는 용해도인자에 의한 용매선택 방법이 신뢰성이 있었고, 용질과 용매의 용해도인자의 차이가 작을수록 추출도가 증가하여 케로진, 크실렌, 클로로포롬, MIBK 및 n-BAc의 순서로 좋아졌다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2010년도 제39회 하계학술대회 초록집
• /
• pp.187-187
• /
• 2010

In this study, we investigated the effect of electrodes on resistance switching of TaOx film. Pt, Ni, TiN, Ti and Al metal electrodes having the different oxidation degree were deposited on TaOx/Pt stack. Unipolar resistance switching behavior in Pt or Ni/TaOx/Pt MIM stacks was investigated, but bipolar resistance switching behavior in TiN, Ti or Al /TaOx/Pt MIM stacks was shown. We investigated that the voltage dependence of capacitance was decreased with higher oxidation degree of metal electrodes. Through the C-V results, we expected that linearity ($\alpha$) and quadratic ($\beta$) coefficient was reduced with an increase of interface layer between top electrode and Tantalum oxide. Transmission Electron Microscope (TEM) images depicted the thickness of interface layer formed with different oxidation degree of top electrode. Unipolar resistance switching behavior shown in lower oxidation degree of top electrode was expected to be generated by the formation of the conducting path in TaOx film. But redox reaction in interface between top electrode and Tantalum oxide may play an important role on bipolar resistance switching behavior exhibited in higher oxidation degree of top electrode. We expected that the resistance switching characteristics were determined by oxidation degree of metal electrodes.