• Title/Summary/Keyword: Empirical Correlation

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A Study on Industry Characteristics of Technology Trade in Korea : evidence from OECD Countries (우리나라 기술무역의 산업별 특성에 관한 연구 : OECD 국가를 대상으로)

  • Baek, Eun-Young;Moon, Hee-Cheol
    • International Commerce and Information Review
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    • v.12 no.4
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    • pp.151-170
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    • 2010
  • The present study made an empirical analysis for investigating the competitiveness of technology trades in Korea. In particular, the study deduced the correlation between technology export and technology import using the variables of Gross Domestic Expenditure on R&D and Per capita industry value added Productivity and employed fixed effect model in panel linear regression model. It is found that the R&D expenditure of OECD countries made a significant effect on the technology import and the value-added labor productivity made a significant result on both technology export and import. Therefore, it showed that the technology trade in Korea made a sensitive response to labor productivity in OECD countries. By panel analysis, machine, construction, ICT, and service industry affect most on technology export in Korea for recent 5 years. For technology import, electric-electron, chemical, service, and construction industry have significant effects. This study contributed to understanding of industrial characteristics affecting technology trades in Korea and empirical analysis to show correlation between the factors affecting technology trade.

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An Empirical Study of SW Size Estimation by using Function Point (기능점수를 이용한 소프트웨어 규모추정 실증연구)

  • Kim, Seung Kwon;Lee, Jong Moo;Park, Ho In
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.7 no.2
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    • pp.115-125
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    • 2011
  • An accurate estimation of software development size is an important factor in calculating reasonable cost of project development and determining its success. In this study, we propose estimation models, using function point based on the functional correlation between software, with empirical data. Three models($FP_{est}(I)$, $FP_{est}(II)$, $FP_{est}(III)$) are developed with correlation and regression analysis. The validity of the models is evaluated by the significance test by comparing values of Mean Magnitude of Relative Error (MMRE) and predictions of each model at level n%. Model $FP_{est}(III)$ proved to be superior to other models such as IFPC(Indicative Function Point Count), EFPC(Estimated Function Point Count), EPFS(Early Prediction of Function Size), $FP_{est}(I)$, and $FP_{est}(II)$. As a result, the accuracy of the model appears to be very high to determine the usefulness of the model to finally overcome weakness of other estimation models. The model can be efficiently used to estimate project development size including software size or manpower allocation.

The Empirical Ambulatory Care Sensitive Conditions Study & its Potential Health Insurance Applicability in Korea (한국형 ACSC에 대한 실증분석 및 건강보험 적용 가능성에 관한 연구)

  • Kim, Yang Yun;Sung, Joo Ho
    • Health Policy and Management
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    • v.15 no.3
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    • pp.79-93
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    • 2005
  • The purpose of the study is to identify Ambulatory Care Sensitive Conditions (ACSC) and their potential health insurance applicability in Korea, using the correlation and regression analysis with the empirical data provided by Korean Health Insurance Review Agency(KHIRA). Here, ACSC would be thought of as conditions that when timely and effectively treated in the outpatient medical services can help reduce the risk of hospitalizations. As for ACSC, reducing accessibility for outpatient visit results in increasing hospitalization. In this respect, the ACSC concept is popularly adopted as one of the performance indicators of the national health system. As one of main results, fortifying the accessibility to necessary health care in a way of sharing appropriately the role with private health insurance can lead to the efficiency of national health care delivery systems in view of total health care expense, in particular in a case of ACSC children. Lastly, we would like to strongly suggest that the disease treatment data set reported to KHIRA needs to be opened to private insurance companies only for illness experience investigation.

A Study on Flow Rate Characteristics of a Triangular Separate Bar Differential Pressure Flow Meter according to the Variation of Gas Flow Temperature (유동 가스 온도 변화에 따른 삼각 분리 막대형 차압 유량계 유량 특성에 관한 연구)

  • Kim, Kwang-Il;Yoo, Won-Yuel;Lee, Choong-Hoon
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.4
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    • pp.89-94
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    • 2008
  • Differential pressure flow meters which have a shape of triangular separate bar(TSB) were tested for investigating the flow rate characteristics of the flow meters with varying the temperature of the gas flow. Three kinds of the triangular separate bar flow meters whose aerodynamic angles are different one another are used. The mass flow rate of the flow meters are evaluated using a non-dimensional parameter which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters, and atmospheric pressure. A burner system which is similar to gas turbine was used for raising the gas flow temperature. The burner system was operated with varying the air/fuel ratio by controlling both the fuel injection rate from the fuel nozzle and air flow rate from a blower. An empirical correlation between the mass flow rate at the TSB flow meter and the non-dimensional parameter was obtained. The empirical correlation showed linear relationship between the mass flow rate and the non-dimensional parameter H. Also, the mass flow rate characteristics at the TSB flow meter was affected by the gas temperature.

Effects of Pressure Tapping Conditions on Flow Rate Measurement of Triangular Separate Bar Differential Pressure Flow Meter (삼각 분리 막대형 차압유량계 압력탭 조건이 유량 측정에 미치는 영향)

  • Lee, Choong-Hoon
    • Journal of the Korean Society of Safety
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    • v.25 no.2
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    • pp.1-6
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    • 2010
  • Flow characteristics of differential pressure flow meters which have a shape of triangular separate bar (TSB) was investigated according to the machining conditions in pressure tapping holes. Diameter of the pressure taping holes is either 1.0 mm or 1.5 mm. Also, number of the pressure tapping holes are drilled either 9 or 17. The mass flow rate of the TSB flow meters are calibrated with a laminar flow meter by connecting them in line. The mass flow rate in the TSB flow meters are plotted with a non-dimensional parameter H which includes the gas temperature, exhaust gas pressure and differential pressure at the flow meters. An empirical correlation between the mass flow rate at the TSB flow meter and the non-dimensional parameter H was obtained. The empirical correlation showed highly linear relationship between the mass flow rate and the non-dimensional parameter H. The hole size of the pressure tapping holes has a bigger effect on the flow rate than the number of the tapping holes.

Seasonality Analysis of Soil Moisture using Cyclostationary Empirical Orthogonal Function (CSEOF 분석을 이용한 토양수분의 계절성 분석)

  • Cho, Eunsaem;Lee, Hyoungtaek;Lee, Myungseob;Lee, Youngju;Yoo, Chulsang
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.282-282
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    • 2016
  • 지표수문해석모형이란 전 지구를 대상으로 수문해석 및 예측이 가능한 분포형 수문모형이다. 본 연구에서는 CSEOF(Cyclostationary Empirical Orthogonal Functions) 분석 방법을 이용하여 지표수문해석 모형 중 하나인 VIC(Variable Infiltration Capacity)모형의 토양수분 모의 성능을 평가해보고자 한다. 이를 위하여 먼저 남한에 대한 VIC 모형으로 모의한 토양수분 예측 결과와 관측자료를 수집하였다. 모의 성능 평가 기간은 1976년부터 2006년까지이다. 이후 본 연구에서는 수집된 VIC 모형의 예측 결과와 관측 자료에 대한 CSEOF 분석을 수행하여 각 자료의 월별 주된 변동 특성을 추출하였다. VIC 모형의 예측 결과와 관측자료의 상관관계는 CSEOF 분석 결과에 대한 Pattern Correlation으로 정량화되었다. 이와 더불어 본 연구에서는 모형의 모의 성능 평가에 주로 사용되는 NRMSE(Nomalized Root Mean Square Error)를 산정하여 예측 결과의 오차를 평가하였다. Pattern Correlation과 NRMSE를 모두 고려하여 VIC 모형의 성능을 평가해본 결과, 건기에 해당하는 기간과 우기에 해당하는 기간의 모의 성능이 다르게 나타났다. 본 연구의 결과는 추후에 지표수문해석 모형의 예측 결과를 이용하는 기후변화 관련 연구에 활용될 수 있을 것으로 판단된다.

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An Empirical Study on the Effects of Trust toward Supervisor on Job Satisfaction and Organizational Commitment in Organization (조직에서 상사에 대한 신뢰가 직무만족 및 조직몰입에 미치는 영향에 관한 실증적 연구)

  • Yang, Hoon-Mo;Cho, Jin-Tak
    • Journal of Industrial Convergence
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    • v.2 no.1
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    • pp.139-158
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    • 2004
  • The purpose of this study is to examine antecedents and outcomes of trust toward supervisor in organization. The model is developed by reviewing previous research providing various perspectives. Antecedents consisted of three trustworthy behaviors - ability, benevolence, integrity - and three transformational leader behaviors - performance management, motivation, team-orientation -, and job satisfaction and organizational commitment is used outcome variables of trust. Data was collected from 206 employees in 6 organizations in broadcasting industry, using self-report questionnaire. Study finding is as following. First, trust in model was composed by 2 type - affect-based trust and cognition-based trust -, not divided in empirical analysis. Second, regression analysis for trust carry out independently, jointly with trustworthy behaviors and leadership behaviors. In antecedents of trust trustworthy behaviors, ability and benevolence has positive effects to trust, integrity has negative relationship with trust. It was high correlation between trustworthy behavior and leadership behavior. Especially, it has highly correlate(correlation efficient 0.69) between ability and team-orientation that influences trust strongly. Third, trust was not significant relationship with individual variables such as age, period with supervisor. Only, it found significant gap in variables and found out different relationship between variables among organizations distinctly. Fourth, job satisfaction and organizational commitment was positive influenced by trust and found out strong relationship between trust and organizational commitment.

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Burst criterion for Indian PHWR fuel cladding under simulated loss-of-coolant accident

  • Suman, Siddharth
    • Nuclear Engineering and Technology
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    • v.51 no.6
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    • pp.1525-1531
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    • 2019
  • The indigenous nuclear power program of India is based mainly on a series of Pressurised Heavy Water Reactors (PHWRs). A burst correlation for Indian PHWR fuel claddings has been developed and empirical burst parameters are determined. The burst correlation is developed from data available in literature for single-rod transient burst tests performed on Indian PHWR claddings in inert environment. The heating rate and internal overpressure were in the range of 7 K/s-73 K/s and 3 bar-80 bar, respectively, during the burst tests. A burst criterion for inert environment, which assumes that deformation is controlled by steady state creep, has been developed using the empirical burst parameters. The burst criterion has been validated with experimental data reported in literature and the prediction of burst parameters is in a fairly good agreement with the experimental data. The burst criterion model reveals that increasing the heating rate increases the burst temperature. However, at higher heating rates, burst strain is decreased considerably and an early rupture of the claddings without undergoing considerable ballooning is observed. It is also found that the degree of anisotropy has significant influence on the burst temperature and burst strain. With increasing degree of anisotropy, the burst temperature for claddings increases but there is a decrease in the burst strain. The effect of anisotropy in the ${\alpha}$-phase is carried over to ${\alpha}+{\beta}$-phase and its effect on the burst strain in the ${\alpha}+{\beta}$-phase too can be observed.

Critical heat flux in a CANDU end shield - Influence of shielding ball diameter

  • Spencer, Justin
    • Nuclear Engineering and Technology
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    • v.54 no.4
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    • pp.1343-1354
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    • 2022
  • Experiments were performed to measure the critical heat flux (CHF) on a vertical surface abutting a coarse packed bed of spherical particles. This geometry is representative of a CANDU reactor calandria tubesheet facing the end shield cavity during the in-vessel retention (IVR) phase of a severe accident. Deionized light water was used as the working fluid. Low carbon steel shielding balls with diameters ranging from 6.4 to 12.7 mm were used, allowing for the development of an empirical correlation of CHF as a function of shielding ball diameter. Previously published data is used to develop a more comprehensive empirical correlation accounting for the impacts of both shielding ball diameter and heating surface height. Tests using borosilicate shielding balls demonstrated that the dependence of CHF on shielding ball thermal conductivity is insignificant. The deposition of iron oxide particles transported from shielding balls to the heating surface is verified to increase CHF non-trivially. The results presented in this paper improve the state of the knowledge base permitting quantitative prediction of CHF in the CANDU end shield, refining our ability to assess the feasibility of IVR. The findings clarify the mechanisms governing CHF in this scenario, permitting identification of potential future research directions.

Bivariate Oscillation Model for Surrogating Climate Change Scenarios in the LCRR basin

  • Lee, Taesam;Ouarda, Taha;Ahn, Yujin
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.69-69
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    • 2021
  • From the unprecedented 2011 spring flood, the residens reside by Lake Champlain and Richelieu River encountered enormous damages. The International Joint Committee (IJC) released the Lake Champlain-Richelieu River (LCRR) Plan of Study (PoS). One of the major tasks for the PoS is to investigate the possible scenarios that might happen in the LCRR basin based on the stochastic simulation of the Net Basin Supplies that calculates the amount of flow into the lake and the river. Therefore, the current study proposed a novel apporach that simulate the annual NBS teleconnecting the climate index. The proposed model employed the bivariate empirical decomposition to contamporaneously model the long-term evolution of nonstationary oscillation embeded in the annual NBS and the climate signal (here, Artic Oscillation: AO). In order to represent the variational behavior of NBS correlation structure along with the temporal revolution of the climate index, a new nonstationary parameterization concept is proposed. The results indicate that the proposed model is superior performance in preserving long and short temporal correlation. It can even preserve the hurst coefficient better than any other tested models.

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