• The Journal of Asian Finance, Economics and Business
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• v.7 no.9
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• pp.95-104
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• 2020

In financial economics studies, the autoregressive model has been a workhorse for a long time. However, the model has a fixed value on every parameter and requires the stationarity assumptions. Time-varying coefficient autoregressive model that we use in this paper offers some desirable benefits over the traditional model such as the parameters are allowed to be varied over-time and can be applies to non-stationary financial data. This paper provides the Monte Carlo simulation studies which show that the model can capture the dynamic movement of parameters very well, even though, there are some sudden changes or jumps. For the daily data from January 1, 2015 to February 12, 2020, our paper provides the empirical studies that Thailand, Taiwan and Tokyo Stock market Index can be explained very well by the time-varying coefficient autoregressive model with lag order one while South Korea's stock index can be explained by the model with lag order three. We show that the model can unveil the non-linear shape of the estimated mean. We employ GJR-GARCH in the condition variance equation and found the evidences that the negative shocks have more impact on market's volatility than the positive shock in the case of South Korea and Tokyo.

• Environmental Engineering Research
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• v.15 no.4
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• pp.231-237
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• 2010

With increased chemical and economic development activities in upstream areas, the amounts of pollutants released have increased, and as such, so has the need for positive management of water supply source areas. Although more than 90% of the water supply sources in Korea depend on direct intake from surface water, the interest in indirect intake, such as riverbank filtration water, has recently risen, with some local governments currently undertaking indirect intake. Even in cases of indirect intake, water supply source protection zones need to be assigned for the comprehensive control of pollutants. To establish water quality protection zones for indirect intake, the scope of the protection zones needed to reflect the hydrological features of the water-bearing deposits of each site. Water source protection areas were estimated and presented as the 1st (within a 100 m radius from an intake well) and 2nd (within a 2 km radius from an intake well) zones. The 1st zone was more sensitive; hence, the installation of various facilities should be prohibited, and the area should be regarded as off-limits. For the 2nd zone, appropriate management should prohibit and restrict activities already present in the water source protection zone.

• International Journal of Quality Innovation
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• v.3 no.2
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• pp.159-173
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• 2002

Any organization's Six Sigma program may be at high risk without heeding the lessons learned from the past and that tries to operate without a robust business foundation. A foundation that preferably should consist of stepping-stones such as a 5-S house-keeping program, an effective Integrated Management System (IMS), which includes a strong focus on planning for quality to fully capture the Voice of the Customer (VOC), and an organization-wide training scheme, as well as a reliable Cost of Poor Quality (COPQ) system. That's the best advise I can give to any organization that wishes to embark on a Six Sigma improvement program and hope to be successful. The paper will elaborate on the above issues and provide suggested solutions based on the review of published historical information and the experiences encountered over the last four decades by the author, as a quality practitioner and consultant, in industries that produced safety-critical product. This author maintains that few fundamentally new or useful things have been created in the field of Quality during the last couple of decades. Nevertheless, this paper deliberates on a number of relatively “newer” issues including the concept of “three types of customers”, the CTC, “Critical To Customer” term, the eight Quality Management Principles of the new ISO 9000 family, the growth of industry-specific standards, the adoption of Integrated Management Systems, the rebirth of AS2561 COQ standard, the spread of Six Sigma as well as related ASQ certification and the need for a robust business foundation to ensure Six Sigma survival.

• Development and Reproduction
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• v.6 no.2
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• pp.89-96
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• 2002

The present study was conducted to elucidate genes involved in the primordial-primary follicular transition. By using suppression subtractive hybridization, day1- and day5-subtracted cDNA libraries were obtained with the forward and reverse subtraction method, respectively. In toto, 357 clones were sequenced and analyzed by BLAST and RIKEN program. Sequences of 330 clones significantly matched database entries while 27 clones were novel. Forty-two and 47 genes with known functions were different between day1 and day5 ovaries. Four genes, GDF8, lats2, septin2, and wee1, from the day1 subtracted cDNA library, and 6 genes, HSP84, laminin2, MATER, MTi7, PTP, and wrn, from day5-subtracted cDNA library were chosen, and their differential expression was evaluated using RNAs from whole ovaries as well as captured primordial and primary follicles by laser captured microdissection. Results from the present study would provide insight for the future study on the mechanisms involved in primordial-primary follicle transition in the mouse in addition to the human ovary.

• The Korean Journal of Zoology
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• v.32 no.3
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• pp.211-220
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• 1989

The fine structure of the aggregate glands-one of the capture thread producing organs-in the orb web spider, Nephila clavata L.Koch, is studied with light and electron microscopes. Gluey capture threads or sticky spirals of the orb web are originated from the silks of two flagelliform glands and four aggregate glands which are connected to the posterior spinnerets, and the arrangement fo their spigots(large spinning tubes) shows a charaterstic form called "triad". The aggregate galnd is composed of large and multilobed secretory portion and thick excretory duct surrounded by large irregular nodules. The excretory duct of the aggregate galnds basically consists of three superposed types of cells which are inner columnar epithelium, nodule-forming cells and outer connestives. The cuticles of the proximal duct near the secretory portion are composed of endocuticle and exocuticle, whereas ghe distal duct near the spinning tubes has a electron lucent subcuticle which had the functions of water removal and orientation of silk fibers. In the cytoplasmic process of the large and irregular nodule-forming cells surrounded by invaginations of the plasma membranes, numerous mitochondria and glycogen particles are contained. The maturational level of the nodule cells is perceived from the appearence of these cell inclusions. The secretory portion of the glands which porduce the secretory silk material shows two layers of the cells which are simple cuboidal epithelium and several connective layers. In the cytoplasm of the glandular epithelial cell, rough endoplasmic reticulums are well developed, and two types of secretory granules are observed. Between the adjacent epithelial cells, specialized septate junctions are formed along the plasma membranes.membranes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.567-577
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• 1996

This study is to estimate population ecological parameters, including growth parameters, survival rates, instantaneous coefficients of natural and fishing mortalities, and age at first capture, as well as growth rates at age of the hairtail, Trichiurus lepturus Linne in Korean waters. For describing the growth of the hairtail, three growth models were fitted, and the von Bertalanffy growth model was adopted for the purpose of the further stock assessment work. The von Bertalanffy growth parameters estimated from a nonlinear regression using EXCEL Solver were $L_\infty=46.01cm$, K=0.3868, and $t_0=-0.3220$. Annual survival rate (S) of the hairtail was estimated to be 0.277 (variance=0.00035) and the instantaneous coefficient of natural mortality (M) was estimated to be 0.441/year. Instantaneous coefficient of fishing mortality (F) for the recent years was calculated as 0.843/year, implying an impact from fishing about two times greater than that of natural mortality. The age at first capture $(t_c)$ was estimated to be 0.787 years, which is much younger age than $50\%$ mature age. Finally, the growth rates at age were estimated.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.343-347
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• 2011

Due to the strong dependence on fossil fuels within the history of human progress, it leads to disaster of the whole world like flood, shortage of water and extinction of the species. In order to curb carbon dioxide emissions, many technologies are being developed. Among them, porous carbon materials have important advantages over other absorbent, such as high surface area, thermal and chemical resistance, low cost, various pore distribution and low energy requirement for their regeneration. Carbon capture and storage (CCS) has attracted the significant research efforts for reducing green house gas emission using several absorbent and process. Moreover, the absorbent are used for the separation of bio mass gas that contains methane which is considered a promising fuel as new green energy resource. In this review, we summarized the recent studies and trend about the porous carbon materials for CCS as well as separation from the biogas.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.311-315
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• 2007

Since the first phase of NGIS (National Geographic Information System) project was launched in 1988, various types and spatial database has been produced and updated. With recent developments in the information technology, the application of spatial data has increased in amount as well as in the coverage of the area of interest. There is a need for production and management of a nationwide single continuous digital map. This paper looks into three problems of map edge matching when dealing with such a task : 1) different scales of adjacent maps, 2) different time of capture between adjacent maps, and 3) different responsible organization where map matching has not been peformed along the boundary.

• Structural Engineering and Mechanics
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• v.30 no.6
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• pp.763-785
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• 2008

In this study, a flexibility-based finite element method considering geometric and material nonlinearities is developed for analyzing steel-concrete frame structures. The stability functions obtained from the exact buckling solution of the beam-column subjected to end moments are used to accurately capture the second-order effects. The proposed method uses the force interpolation functions, including a moment magnification due to the axial force and lateral displacement. Thus, only one element per a physical member can account for the interaction between the bending moment and the axial force in a rational way. The proposed method applies the Newton method based on the load control and uses the secant stiffness method, which is computationally both efficient and stable. According to the evaluation result of this study, the proposed method consistently well predicts the nonlinear inelastic behavior of steel-concrete composite frames and gives good efficiency.

• Journal of the Korean Home Economics Association
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• v.37 no.7
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• pp.127-141
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• 1999

The purpose of this study is to classify the elderly over the age of 60 according to their lifestyles and analyze the health and economic status of them that are classified. Data were obtained from 463 elderly living in urban areas. Factor analysis was used for examining dimensions of lifestyles and cluster analysis for classifying the elderly by lifestyles. This study found six different types of lifestyles, Le., the actively self-developing type, the individualist seeing the negative aspects of the world, the sensuous joy oriented type, the obedient to the tradition type, the conservative with discontented attitude toward the world, and the introspective self-fulfilling type. There were significant differences in living status as well as socio-economic characteristics of the elderly among six types of lifestyles. From the results of this study, it is found that the elderly have various lifestyles and, therefore, the understanding the lifestyles of the elderly will enable researchers to capture the problems the elderly face and provide more insight into their living status.