• Title/Summary/Keyword: 선행 연구

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The Study on the Usefulness of Short-run GDP Forecasting Using Generation (발전량을 이용한 단기 GDP 전망의 유용성 연구)

  • Paik, Kwang-Hyun;Kim, Kwon-Soo;Park, Jong-In
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.808-809
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    • 2007
  • 전력수요는 경기변동과 밀접한 관련성을 가지고 동행적으로 움직이며, 전력자료는 경제자료에 비해 조기 관측되는 선행성이 있다. 본 연구에서는 GDP 전망을 위해 발전량이 유용하게 사용될 수 있는가를 살펴 보았다. 발전량과 GDP의 관련성은 그랜저 인과관계 검정을 통해서 검증해 보았으며, 발전량 자료 취득의 선행성은 선행차수를 변화시켜 보면서 관련성이 어떻게 변하는가를 살펴보았다. 실제 자료를 이용하여 분석하고, 2004년부터 2006년 기간의 전망치를 평가한 결과, 본 논문에서 살펴 보고자 했던 발전량과 GDP 사이에는 아주 높은 관련성이 있음을 확인할 수 있었고 또한 발전량 자료를 이용함으로써 실제로 GDP 전망의 예측력을 상당히 개선시킬 수 있음을 볼 수 있었다. 발전량과 GDP 사이의 관계는 시간변동계수를 가지는 공적분 및 오차수 정모형을 이용하여 모형화하였다.

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A Study for Reducing Traffic Accident at Signalized Intersection - Focus on Left-turn Phase Sequence - (교차로 교통사고 감소방안에 관한 연구 - 좌회전 현시 순서를 중심으로 -)

  • Park, Jong-Wook;Lee, In-Won;Lee, Choul-Ki;Yang, Lyun-Ho;Lee, Gun-Sang
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.5 no.2 s.10
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    • pp.61-71
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    • 2006
  • The main purpose of this study is to search a method for reducing traffic accident at signalized intersections. One of the important factors for this is the Left-turn phase sequence. In 1985, the operational principle of Left-turn phase Sequence was changed from Lagging left-turn to Leading left-turn in Korea. Then there was a resonable motive-no exclusive left turn-lane and narrow intersection. So, it is necessary to evaluate the performance difference between Leading and Lagging left -turn phase Sequence. The process of this study is as follows: $\cdot$ First, all the intersection was divided three parts for analysis the traffic safety: Inside part of an Intersection, Crosswalk, Intersection approach and exit. $\cdot$ Second, a safety analysis was performed by using the concepts of 'Effective interphase Period(EIP)' and 'Conflict method' The Study result is that the benefit of of phase Sequence changes from Leading to Lagging phase were significant. For an example the Accident cost will reduced about 41.8 billion won per year in korea.

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Study on Prediction of Performance with Design Variables of Solar-Assisted Still Using Waste Heat from Diesel Generator (디젤 발전기 폐열을 활용한 태양열원 해수담수기의 설계변수에 따른 성능 예측에 관한 연구)

  • Jang, Hyun;Yi, Chung Seob;Suh, Jeong Se;Jeong, Kyoung Yul;Park, Change Dae
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.12
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    • pp.1061-1068
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    • 2013
  • This study predicts distillate productions according to design variables by numerical analysis when the waste heat from a diesel generator is added to the solar-assisted still proposed in a previous study. Mathematical models were set up in reference to previous studies, and the amount of heat exchange from the waste heat recovery pipe was considered. To ensure the reliability of numerical analysis, the result was compared with that of a previous study and then, the distillate productions according to design variables were obtained by the analysis model. The results were found to generally be in agreement, and the increasing amount of distillate production of the still with the added waste heat was confirmed. In addition, the optimal value of the tilt angle of glass cover and the number of cells were determined by numerical analysis.

A Study on the Relationship Between Depressive Symptoms and Alcohol Use - Focusing on 'Tension Reduction Theory' and 'Intoxication Theory'- (우울과 음주의 관계에 대한 연구 - '긴장감소가설'과 '독성가설'에 대한 검증을 중심으로 -)

  • Kahng, Sang-kyoung;Kwon, Tae-yeon
    • Korean Journal of Social Welfare Studies
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    • no.36
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    • pp.253-280
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    • 2008
  • Previous research indicates that depressive symptoms and alcohol consumption are highly correlated with each other. However, there is lack of consensus on the causal relationship between depressive symptoms and alcohol use. In order to address this limitation, this paper examines causal relationship between the two variables using non-recursive structural equation modeling, controlling sociodemographic and psycho-socio-behavioral variables. Data included 14,469 community dwelling individuals who participated in Korea Welfare Panel Study in 2006. Results showed that the effects of alcohol consumption on depressive symptoms was statistically significant, whereas the effects of depressive symptoms on alcohol consumption was not. Significant portions of the effects of psycho-socio-behavioral variables on depressive symptoms were indirect through their effects on alcohol consumption. Based on the results, implications for intervention and future research were discussed.

The Effect of Managerial Information Security Intelligence on the Employee's Information Security Countermeasure Awareness (경영진의 정보보안 지능이 조직원의 보안대책 인식에 미치는 영향)

  • Jin Young Han;Hyun-Sun Ryu
    • Information Systems Review
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    • v.18 no.3
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    • pp.137-153
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    • 2016
  • Organizations depend on smart working environments, such as mobile networks. This development motivates companies to focus on information security. Information leakage negatively affects companies. To address this issue, management and information security researchers focus on compliance of employees with information security policies. Countermeasures in information security are known antecedents of intention to comply information security policies. Despite the importance of this topic, research on the antecedents of information security countermeasures is scarce. The present study proposes information security intelligence as an antecedent of information security countermeasures. Information security intelligence adapted the concept of safety intelligence provided by Kirwan (2008). Information security intelligence consists of problem solving skills, social skills, and information security knowledge related to information security. Results show that problem solving skills and information security knowledge have positive effects on the awareness of employees of information security countermeasures.

Structural Optimization and Improvement of Initial Weight Dependency of the Neural Network Model for Determination of Preconsolidation Pressure from Piezocone Test Result (피에조콘을 이용한 선행압밀하중 결정 신경망 모델의 구조 최적화 및 초기 연결강도 의존성 개선)

  • Kim, Young-Sang;Joo, No-Ah;Park, Hyun-Il;Park, Sol-Ji
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3C
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    • pp.115-125
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    • 2009
  • The preconsolidation pressure has been commonly determined by oedometer test. However, it can also be determined by insitu test, such as piezocone test with theoretical and(or) empirical correlations. Recently, Neural Network (NN) theory was applied and some models were proposed to estimate the preconsolidation pressure or OCR. It was already found that NN model can come over the site dependency and prediction accuracy is greatly improved when compared with present theoretical and empirical models. However, since the optimization process of synaptic weights of NN model is dependent on the initial synaptic weights, NN models which are trained with different initial weights can't avoid the variability on prediction result for new database even though they have same structure and use same transfer function. In this study, Committee Neural Network (CNN) model is proposed to improve the initial weight dependency of multi-layered neural network model on the prediction of preconsolidation pressure of soft clay from piezocone test result. Prediction results of CNN model are compared with those of conventional empirical and theoretical models and multi-layered neural network model, which has the optimized structure. It was found that even though the NN model has the optimized structure for given training data set, it still has the initial weight dependency, while the proposed CNN model can improve the initial weight dependency of the NN model and provide a consistent and precise inference result than existing NN models.

Influence of Antecedent Rainfall in Stability Analysis of Unsaturated Soil Slope (불포화토 사면 안정해석에서 선행강우의 영향에 관한 연구)

  • Lee, Yeongsaeng;Yoon, Seunghyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.5
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    • pp.1073-1082
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    • 2015
  • The behavior of the unsaturated soil slope can be influenced by the various factors such as the hydraulic characteristics, the mechanical characteristics, the coefficient of conductivity, the stratifications, the rainfall conditions i.e. the rainfall intensity, the rainfall pattern, the duration time of the rainfall and the antecedent rainfall etc. It is known that the slope failure is influenced greatly by the antecedent rainfall rather than the rainfall condition at the failure time, so the antecedent rainfall is supposed to be a very important factor in slope stability analysis among these factors. To predict and to prevent the slope failure by the rainfall, the distribution of the matric suction by the antecedent rainfall must be considered first of all and the slope stability analysis should be carried out by considering the successive rainfall characteristics. In this research, 3 samples with different quantity (5%, 10%, 20%) of silts were prepared and the SWCC (Soil-water characteristic curve) tests were carried out and the associated parameters were analyzed. After analyzing the distribution of the matric suction and the change of the mechanical characteristics such as the stress and the strength when applying the antecedent rainfall for one month and the successive intensive rainfall for 12 hours, the slope stability analyses were carried out numerically. And the influence of the antecedent rainfall for one month and the SWCC on the stability of a slope were compared and analyzed.

Analysis of KOSPI·Apartment Prices in Seoul·HPPCI·CLI's Correlation and Precedence (종합주가지수·서울지역아파트가격·전국주택매매가격지수·경기선행지수의 상관관계와 선행성 분석)

  • Choi, Jeong-Il;Lee, Ok-Dong
    • Journal of Digital Convergence
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    • v.12 no.5
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    • pp.89-99
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    • 2014
  • Correlation of KOSPI from stock market and Apartment Prices in Seoul HPPCI from real estate market has been found from this research. Furthermore, from the comparison of those indicators' flows, certain precedence was found as well. The purpose of this research is to analyze correlation and precedence among KOSPI, Apartment price in Seoul, HPPCI and CLI. As for predicting KOSPI of stock market and real estate market, it is necessary to find out preceding indices and analyzing their progresses first. For 27 years from the January 1987 to December 2013, KOSPI has been grown by 687%, while CLI showed 443%, Apartment of Seoul showed 391%, HPPCI showed 263% of growth rate in order. As the result of correlation analysis among Apartment of Seoul, CLI, KOSPI and HPPCI, KOSPI and HPPCI showed high correlation coefficient of 0.877, and Apartment of Seoul and CLI showed that of 0.956 which is even higher. Result from the analysis, CLI shows high correlation with stock and real estate market, it is a good option to watch how CLI flows to predict stock and real estate market.

Curve Number for a Small Forested Mountainous Catchment (산지 소유역 유출곡선지수)

  • Oh, Kyoung-Doo;Jun, Byong-Ho;Han, Hyung-Geun;Jung, Sung-Won;Cho, Young-Ho;Park, Soo-Yun
    • Journal of Korea Water Resources Association
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    • v.38 no.8 s.157
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    • pp.605-616
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    • 2005
  • In this paper, runoff curve numbers (CN's) for a small forested mountainous catchment are estimated using rainfall-runoff data measured at Sulma experimental catchment every 10 minutes and a new guideline for applying the antecedent rainfall conditions (ARC's) for small mountainous watersheds in Korea is proposed. Sulma experimental catchment is a typical natural mountainous basin with $97\%$ of forested land cover and CN's are estimated to be in the range between 51 and 89 with median value of 72. The test hypothesis stating as 1-day ARC is better than 5-day ARC in determining CN's for a small mountainous watershed is shown to be acceptable. Also, linear regression equations for the estimation of CN's for small mountainous catchments are proposed. As there is no significant investigations available on CN's for small mountainous catchments, the newly proposed relationships between CN's and ARC may be used as a preliminary guideline to assign CN's for the estimation of floods from rainfall data on mountainous regions.

A study on consonantal voicing-dependent vowel duration in English (영어의 자음 유.무성 대립과 선행모음길이와의 상관관계 연구)

  • 고현주
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1998.06c
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    • pp.399-402
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    • 1998
  • 영어에서 자음의 유.무성 대립이 선행모음에 미치는 영향은 다른 여느 언어에서보다 두드러지게 커서 언어 보편적이기보다는 영어 특유의 음운현상으로 보는 견해가 주류를 이루고 있다. 본 연구에서는 영어를 학습하고 있는 한국어 화자들이 영어특유의 이 현상을 어떻게 인지하여 실현하고 있는지를 발성실험을 통하여 알아보고 더 나아가 모음길이가 후행자음의 유.무성 인지에 어떤 실마리로 작용하는지 인지실험을 통하여 알아보았다.

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