• The Korean Journal of Ecology
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• v.22 no.2
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• pp.89-94
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• 1999

Thirty-day-old seedlings of tomato (Lycopersicon esculentum) were treated with different concentrations of HgCl$_2$(0. 10 and 50 $\mu$M) for up to 20 days. and the detailed distribution of Hg absorbed and its toxicity in different plant parts (roots, stems and leaves) were investigated. The accumulation of Hg in plants increased with external Hg concentrations. and Hg is strongly retained by roots. Further. Hg content in leaves was various. showing more accumulation in older leaves. Seedlings exposed to toxic levels of Hg showed not only the reduction of dry weight and length of both shoot and root. and chlorophyll levels in leaves but also the enhancement of malondialdehyde (a lipid peroxidation product) formation in all plant parts investigated. These results suggest that physiological impairment of a plant exposed to Hg may be achieved by internal distribution of Hg absorbed and Hg-induced oxidative stress in different plant parts.

• Journal of the Korean Wood Science and Technology
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• v.44 no.6
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• pp.903-912
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• 2016

Morphological and anatomical evaluation of grafted P. merkusii have been undertaken to obtain the information about compatible and incompatible symptoms of 18 years old grafts based on morphological observation and microscopic analysis. Samples of compatible and incompatible grafts were obtained from previous research conducted by the Silviculture Departement Team in 1994. Result showed that compatible grafts have normal stem form and secondary growth (diameter growth), but some abnormality symptoms like undulated pattern of annual growth rings, phloem thickening and abnormality resin ducts in inner and middle parts of the union area occurred. Incompatible ones showed abnormality of the stem form, cortex-bark necrosis and swelling in the union area. Microscopic observation showed abnormality of all parts of the union, undulated pattern of annual growth rings, phloem thickening, abnormal resin ducts, low numbers and discontinuity of vascular elements in the union area.

• Korean Journal of English Language and Linguistics
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• v.3 no.2
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• pp.211-231
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• 2003

The study of English words in terms of etymology has a long history, going back over 110 years since Murray et al. (1884). Scholars have therefore had lots of time to gather all kind of information on the origin of English words. In fact, Modern English is the product of a long and complex process of historical developments from a great diversity of sources. The origins and development of English words meaning ‘a vessel for washing, a bath or a toilet’ are traced from Old English to the twentieth century in this paper in terms of the semantic and/or conceptual categories of the words with their particular senses. We conclude this paper with a brief discussion of how the teaching of English words can give some feedback to both teachers and students under the circumstances of English education in Korea and/or how we come to a better understanding of this charming field of English etymology in its own right.

• Journal of Information Processing Systems
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• v.6 no.2
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• pp.219-234
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• 2010

Gaming is an old humans' habit. Games help in logical development and encourage learning of theoretical and practical concepts. Besides they offer entertainment and challenge. The advent of the personal computer changed this tradition. Every year new challenges arise in a digital format, which lead the young and adults to spend hours in front of a computer or TV screen in an attempt to overcome hurdles and reach an objective. Quality, sophistication, and constant innovation are attained through complex computer software that almost has an obligation to improve as each new title is released, due to this game development becomes a challenge. Considering that a game title is software and thus faces the same restrictions of business applications, this article intends to analyze, under the optics of reuse, if game development resorts to reuse, and where and how this happens.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.2
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• pp.217-228
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• 1994

This paper presents a new integer formulation (Type III ALB) for a single model assembly line balancing problem. The objective of the formulation is to minimize the total idle time, which is defined as the product of the number of work stations and the cycle times minus the total work content. This formulation considers currently existing Type I (minimizing the number of work stations for a given cycle time) and type II (minimizing the cycle time for a given number of work stations) formulations as its special cases and provides the global minimum solutions of the cycle time and the number of work stations. This information would be of great value to line designers involved in designing new assembly lines and rebalancing old lines under flexible conditions. Solution methods based on combination of Type I and Type II approaches are also suggested and compared.

• Korean Journal of Mathematics
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• v.26 no.1
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• pp.103-127
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• 2018

This paper is dedicated to studying some Hausdorff operators on the Heisenberg group ${\mathbb{H}}^n$. The sharp bounds on the strong-type weighted Lorentz spaces ${\Lambda}^p_u(w)$ and the weak-type weighted Lorentz spaces ${\Lambda}^{p,{\infty}}_u(w)$ are investigated. Especially, the results cover the classical power weighted space $L^{p,q}_{\alpha}$. The results are also extended to the product spaces ${\Lambda}^{p_1}_{u_1}(w_1){\times}{\Lambda}^{p_2}_{u_2}(w_2)$, especially for $L^{p_1,q_1}_{{\alpha}_1}{\times}L^{p_2,q_2}_{{\alpha}_2}$. Our proofs are quite different from those in previous documents since the duality principle, and some well-known inequalities concerning the weights are adopted. The results recover the existing results as well as we obtain new results in the new and old settings.

• Korean Journal of Child Studies
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• v.31 no.1
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• pp.235-248
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• 2010

The purpose of this study was to establish strategies that support multi-cultural children' development and adaptation in day care centers. The subjects were 61 young children, 49 parents from multi-cultural family and 550 Korean young children. The instruments utilized were the Sukemune-Hiew Resilience Test for parents and the Danaka Deveopment Test for children. The statistical instruments used were the t-test and the Pearson product correlation coefficients. Our results indicated that : (1) In the case five or six years old children from multi-cultural families, language development lagged behind that of Korean children. (2) Social support systems were insufficient for parents of multi-cultural families. Our cnclusions suggest that establishing strategies is necessary for not only supporting the linguistic development of children from multi-cultural families, but strategies aimed at supporting their parents in day care centers need to be developed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.1 no.1
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• pp.51-62
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• 1972

In Korea, fermented fish has been playing an important role as a preserved and flavor rich food. It is said that the digestion of fish protein is due to both action of intrinsic (autolytic enzymes) and bacterial enzymes in fish. The mass production of fermented fish has been impeded since traditional method of fermentation requires a long duration for a complete digestion. A high concentration of salt and unsanitary condition are also considered disadvantages of the old method. To improve the quality of the product and to develop mechanized process of fermentation, fermentors which have such control device as temperature, pH and agitation control system have been urgently needed. In this study, a model design of a fermentor is studied. The calculation was based on the optimum conditions for enzymatic hydrolysis of fish protein which involve temperature, pH, viscosity and other factors.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1187-1192
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• 2003

The computer is an important tool to design an engineering system and CAD systems are widely used for various design practice. To meet the market requirements, the old mass production system is being changed into the mass customization system. As for CAD systems, it is increasingly required to extend, automate, and customize a wide range of functionality. This article describes the state-of-the-art of the principal technologies for customizing CAD systems. And we have implemented an application that enables the parametric design by directly inputting numerical values of parameters for a CAD model. Based on this application, we have developed another system that makes it possible sharing of part family data between SolidEdge and Pro/Engineer. Through customization of CAD systems, it is possible to improve the product quality using external knowledge-based systems or to integrate with external system such as CAE tools. This paper can be a guide for engineering designers who want to customize CAD systems.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1578-1583
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• 2007

The suspension system of railway rolling-stock is composed of the primary and secondary suspension elements. Recently, a conical rubber spring is widely used as the primary suspension element due to the merits of the three directional stiffness characteristics. So, understanding the properties and characteristics of the conical rubber spring is very important from the viewpoint of vehicle stability and efficient maintenance. Thus, this study is started to acquire the basic data for maintaining spring elements efficiently. For this, we tested the conical rubber spring samples including a new and old specimen with aging. As a test result, we have obtained the property characteristics of the aged spring comparing with the new product and we describe the results.