• Journal of the Korea Concrete Institute
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• v.18 no.6 s.96
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• pp.759-767
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• 2006

This paper presents a method to estimate the setting time of concrete using super retarding agent(SRA) and fly ash(FA) under various curing temperature conditions by applying maturity based on equivalent age. To estimate setting time, the equivalent age using apparent activation energy($E_a$) was applied. Increasing SRA content and decreasing curing temperature leads to retard initial and final set markedly. $E_a$ at the initial set and final set obtained by Arrhenius function showed differences in response to mixture type. It is estimated to be from $24{\sim}35KJ/mol$ in all mixtures, which is smaller than that of conventional mixture ranging from $30{\sim}50KJ/mol$. Based on the application of $E_a$ to Freisleben-Hansen and Pederson's equivalent age function, equivalent age is nearly constant, regardless of curing temperature and SRA contents. This implies that the concept of maturity is applicable in estimating the setting time of concrete containing SRA. A high correlation between estimated setting time and measured setting time is observed. Multi-regression model to determine appropriate dosage of SRA reflecting FA contents and equivalent age was provided. Thus, the setting time estimation method studied herein can be applicable to the concrete containing SRA and FA in construction fields.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.11
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• pp.1575-1589
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• 2017

Objective: This study was conducted to determine molecular structures related to carbohydrates and lipid in alfalfa hay cut at early bud, late bud and early flower and in the afternoon and next morning using Fourier transform infrared spectroscopy (FT/IR) and to determine their relationship with alfalfa hay nutrient profile and availability in ruminants. Methods: Chemical composition analysis, carbohydrate fractionation, in situ ruminal degradability, and DVE/OEB model were used to measure nutrient profile and availability of alfalfa hay. Univariate analysis, hierarchical cluster analysis (CLA) and principal components analysis (PCA) were conducted to identify FT/IR spectra differences. Results: The FT/IR non-structural carbohydrate (NSCHO) to total carbohydrates and NSCHO to structural carbohydrate ratios decreased (p<0.05), while lignin to NSCHO and lipid CH3 symmetric to CH2 symmetric ratios increased with advancing maturity (p<0.05). The FT/IR spectra related to structural carbohydrates, lignin and lipids were distinguished for alfalfa hay at three maturities by PCA and CLA, while FT/IR molecular structures related to carbohydrates and lipids were similar between alfalfa hay cut in the morning and afternoon when analyzed by PCA and CLA analysis. Positive correlations were found for FT/IR NSCHO to total carbohydrate and NSCHO to structural carbohydrate ratios with non-fiber carbohydrate (by wet chemistry), ruminal fast and intermediately degradable carbohydrate fractions and total ruminal degradability of carbohydrates and predicted intestinal nutrient availability in dairy cows ($r{\geq}0.60$; p<0.05) whereas FT/IR lignin to NSCHO and CH3 to CH2 symmetric stretching ratio had negative correlation with predicted ruminal and intestinal nutrient availability of alfalfa hay in dairy cows ($r{\geq}-0.60$; p<0.05). Conclusion: FT/IR carbohydrate and lipid molecular structures in alfalfa hay changed with advancing maturity from early bud to early flower, but not during the day, and these molecular structures correlated with predicted nutrient supply of alfalfa hay in ruminants.

• Journal of Navigation and Port Research
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• v.41 no.4
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• pp.235-242
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• 2017

Earnings management is defined as an intentional act during the financial reporting process or a manager's choice of accounting policies to avoid earnings decreases or obtain some private gains. Shipping firms have a highly debt-intensive capital structure and a significant motivation in earnings management to avoid failure of a Debt Covenant. From this point of views, this paper tries to determine the relationship between the capital structure and discretionary accruals estimated using the re-modified Jones model (1995). The sample used to test the research models is made up of 87 Korean shipping firms during the period from 2007 to 2015. A histogram analysis, t-test and FGLS confirm the possibility of using earnings management, and it proved that Korean shipping firms manage their earnings to avoid financial loss. An analysis of the relationship between the capital structure and earning managements, shows it is difficult to support the Debt Covenant, shown as a negative relationship between the debt ratio and debt maturity as shipping firms' capital structure and discretionary accruals as earning management variable. An additional analysis presents a negative relationship between previous debt maturity and discretionary accruals, and the possibility of earning management in a highly increased debt ration group.

• Journal of Korean Society of Forest Science
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• v.32 no.1
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• pp.9-15
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• 1976

Financial rotations of Pinus koraiensis stands are calculated and compared on the basis of five basic financial maturity concepts. The rotations given by the forest rent and average annual gross revenue models are in excess of sixty years by adopting zero interest rates of capital and forest lands. IRR model also neglects land value and highly sensitive to the changes of fixed and regeneration costs. The Faustmann doctrine recommands rotation ages of 23-39 years depend upon applied interest rates and site indices, and seems to be most adequate for determining financial maturity. It is however the situation in Korea that economic conditions are changing rapidly, and thus a model which does not require many exogenous variables in calculation process is preferable. The Duerr's solution has a basic simplicity and logic which is appealing from both a theoritical and practical viewpoint, and most adaptable to the Korean situation, even though the model completly neglects the opportunity cost for forest land. There is a tendency to reduce rotation length with the increase of site quality, but the difference is negligible.

• Industrial Engineering and Management Systems
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• v.11 no.3
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• pp.233-240
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• 2012

The implementation of business process management (BPM) systems in large number of business organizations transforms BPM system into such a level of maturity and tends to collect large repositories of business process (BP) models. This issue encourages BP flexibility that leads to a large number of process variants derived from the same model, but differing in structure, to be stored in the large repositories of BP models. Therefore, the repositories may include thousands of activities and related business objects with variation of requirements and quality of service. It is a common practice to customize processes from reference processes or templates in order to reduce the time and effort required to design and deploy processes on all levels. In order to address redundancy and underutilization problems, a generic process model, called as reference BP, is absolutely necessary to cover the best of process variants. This study aims to develop multiple-objective business process genetic algorithm (MOBPGA) to find a set of non-dominated (Pareto) solutions of business reference model to enhance conventional approach which considered only a single objective on creating BP reference model by using proximity score measurement. A mixed-integer linear program is constructed to evaluate performance of the proposed MOBPGA on small-scale problems by using standard measures for multiple-objective techniques. The results will show the viability of applying MOBPGA in terms of simultaneously maximizing proximity score measurement, minimizing total duration, and total costs of the selected reference model.

• The Korean Journal of Applied Statistics
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• v.28 no.3
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• pp.393-406
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• 2015

We examine how to model mortality risk using the adaptation of the mean-reverting processes for the two factor model proposed by Cairns et al. (2006b). Mortality improvements have been recently observed in some countries such as United Kingdom; therefore, we assume long-run mortality converges towards a trend at some unknown time and the mean-reverting processes could therefore be an appropriate stochastic model. We estimate the parameters of the two-factor model incorporated with mean-reverting processes by a Metropolis-Hastings algorithm to fit United Kingdom mortality data from 1991 to 2015. We forecast the evolution of the mortality from 2014 to 2040 based on the estimation results in order to evaluate the issue price of a longevity bond of 25 years maturity. As an application, we propose a method to quantify the speed of mortality improvement by the average mean reverting times of the processes.

• Animal Bioscience
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• v.34 no.4
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• pp.471-481
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• 2021

Objective: A comprehensive study was conducted to study the effects of partition of variance on accuracy of genetic parameters and genetic trends of economic traits in Vanaraja male line/project directorate-1 (PD-1) chicken. Methods: Variance component analysis utilizing restricted maximum likelihood animal model was carried out with five generations data to delineate the population status, direct additive, maternal genetic, permanent environmental effects, besides genetic trends and performance of economic traits in PD-1 chickens. Genetic trend was estimated by regression of the estimated average breeding values (BV) on generations. Results: The body weight (BW) and shank length (SL) varied significantly (p≤0.01) among the generations, hatches and sexes. The least squares mean of SL at six weeks, the primary trait was 77.44±0.05 mm. All the production traits, viz., BWs, age at sexual maturity, egg production (EP) and egg weight were significantly influenced by generation. Model four with additive, maternal permanent environmental and residual effects was the best model for juvenile growth traits, except for zero-day BW. The heritability estimates for BW and SL at six weeks (SL6) were 0.20±0.03 and 0.17±0.03, respectively. The BV of SL6 in the population increased linearly from 0.03 to 3.62 mm due to selection. Genetic trend was significant (p≤0.05) for SL6, BW6, and production traits. The average genetic gain of EP40 for each generation was significant (p≤0.05) with an average increase of 0.38 eggs per generation. The average inbreeding coefficient was 0.02 in PD-1 line. Conclusion: The population was in ideal condition with negligible inbreeding and the selection was quite effective with significant genetic gains in each generation for primary trait of selection. The animal model minimized the over-estimation of genetic parameters and improved the accuracy of the BV, thus enabling the breeder to select the suitable breeding strategy for genetic improvement.

• Journal of Korean Society for Quality Management
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• v.31 no.1
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• pp.76-89
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• 2003

Recently, CMM have been recognized as a critical factor to validate the competitiveness of software organizations, even if the organizations have already achieved the ISO9001 certification. Furthermore, the new version of ISO9001:2000 is being required instead of ISO9001:1994. Both CMM and ISO9001 have a common point that they pursuit quality improvement for the organizations processes and products. Therefore, it is important to understand the similarities of specific requirements between the two models in software organizations which attempt to employ both of the models. From this background, this paper compares CMM and ISO9001 by considering the versions in 1994 and 2000 of ISO9001. The results of this research are likely to help software organizations ma]fe a decision for a strategy to adopt CMM and ISO9001.

• The Journal of Fisheries Business Administration
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• v.38 no.2
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• pp.63-78
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• 2007

The objective of this study is to examine the speculative efficiency of shrimp futures market. Testing for the speculative efficiency hypothesis is carried out using Johansen's the maximum-likelihood cointegration method and Fama(1984) regressison model. Analysis data are obtained Kansai Commodities Exchange in Osaka and are daily data of frozen shrimp futures and cash prices for all trading days in the time period from September 6, 2002, frozen shrimp futures is introduced, to May 10, 2007. The empirical results are summarized as follows:First, there exists the cointegrating relationship between realized spot India 16/20, Indonesia 16/20, vietnam 16/20 prices and futures prices of the 14 day to maturity. Second, shrimp futures contract prices do not behave as unbiased predictor s of future spot shrimp prices. This indicates that the shrimp futures market is inefficient.

• 한국경영정보학회:학술대회논문집
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• 2008.06a
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• pp.850-858
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• 2008

최근 공공기관 및 금융권에서는 경쟁력 향상을 위한 정보시스템의 통합으로 프로젝트 규모가 대형화되고 또한, 프로젝트 수가 증가하고 있어 적절한 소프트웨어 프로젝트 관리 방안이 필요하다. 그러나 프로젝트 관리 영역간의 미치는 영향에 대하여 체계적인 연구가 미흡하였다. 따라서 선행 연구를 통하여 프로젝트 관리에 중요한 영역을 도출하였고, 도출된 "범위, 일정, 품질, 인력, 위험"의 각 영역들간의 상호 미치는 영향도의 분석과 각 영역의 진행 상태를 "계획, 실행, 완료" 단계로 구분하여 수행도를 분석하였다. 분석된 영향도와 수행도의 결과를 종합하여 프로젝트 관리 수준을 평가하는 모델을 제시하였다. 본 연구는 IT 분야의 전문가 그룹을 통해 프로젝트 관리 영역들간의 영향 분석이 실증적으로 연구가 이루어졌고, 또한 각 영역의 진행상태를 측정 함으로써 실무적인 측면에서 더욱 체계적이고 균형 잡힌 프로젝트 관리와 감리 수행 시에 활용할 수 있을 것이다.