• Journal of the Korean Ceramic Society
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• v.33 no.10
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• pp.1163-1169
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• 1996

The effects of borax on the phase formation of C2S, C4A3 and $\alpha$'-C2S phases. It has negative effects on formation of C4A3 And it lowers the forming temperature of C4AF. It also has been found that borax improves the clinkerization of MBC. In the MBC clinker with borax 3% C2S have larger and more irregular shapes, larger C/S mole ratio and C4A3 have smaller size larger C/ molr ratio than in the clinker without borax.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.1-10
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• 1991

Two-dimensional explicit finite element code was developed. The transient dynamics code can analyse large deformations of non-linear materials subjected to extremely high strain rates. The Lagrangian finite element program uses an explicit time integration operator to integrate the equations of motion, thus the stiffness matrix is not introduced. Cylinder upsetting and ring compression problems are simulated to check the effects of friction and inertia force. It is shown that (1) calculated results agree very well with experimental results, (2) constant shear friction method overestimates the decrease of inner ring radius and then underestimates after on in comparison with the Coulomb friction method, and (3) the effect of the increase in initial strain rate is similar to the effect of higher frictional coefficient.

• Journal of Oriental Neuropsychiatry
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• v.8 no.2
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• pp.13-24
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• 1997

This study was done to know the effects of the water extracts of Gyogamdan(GGD) on the function of macrophages, the most important cells of the innate immune system, and the rosette forming ability of splenocytes in the mouse under stress. The effects of GGD on the immunosuppression induced by noise stress are as follows. 1. Administration of GGD water extracts normalized the bo요 weight which might be decreased by noise stress. 2. Administration of GGD water extracts increased the production of the such reactive oxygen intermediates as superoxide and hydrogen peroxide from macrophsges in vivo & in vitro which were decreased by noise stress. 3. Administration of GGS water extracts did not affect the production of reactive nitrogen intermediates. 4. Administration of GGD water extracts increased the rosette forming ability of splenocytes which was decreased by noise stress. The above effects of GGD might be useful for the treatment of stress-induced infections diseases which could be caused by the suppression of immune responeses which are initiated by the functions of macrophages of the innate immune system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.347-355
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• 2014

This study examined the effects of additives on the physical properties of surimi made from Antarctic krill Euphausia superba. Krill surimi was prepared from krill meat with an added cryoprotectant (sugar 6%, polyphosphate 0.2%). Krill surimi without additives does not form a gel. In order to enhance the gelling of krill surimi, additives such as soy protein isolate (SPI), guar gum, carrageenan, and wheat starch were examined. Of these, SPI had the highest gel-forming activity, while guar gum, carrageenan, and wheat starch had decreasing gel-forming activity and negative effects on other physical properties as their concentrations were increased. In addition, SPI enhanced the gel strength and physical properties of krill surimi. The fluoride and astaxanthin contents of krill surimi with added SPI were 55.0 mg/kg and 0.8 mg/kg, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.160-168
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• 2017

Optimizing the conditions for stem cell culture is an essential prerequisite for the efficient utilization of stem cells. In the culture of fish embryonic stem cells (ESCs) or ESC-like cells, embryo extracts are important for stable growth, but there is no rule for determining the developmental stage of the embryos used to obtain extracts. Therefore, this study investigated the effects of the developmental stage of extract donor embryos on the culture of Oryzias dancena ESC-like cells. O. dancena ESC-like cells were cultured in different media containing each of four types of embryo extract depending on the developmental stage of the extract donor embryos. Growth, morphology, colony-forming ability, alkaline phosphatase (AP) activity, and embryoid body (EB) formation of the cells were investigated. While the developmental stage of the extract donor embryos did not influence the growth, morphology, AP activity, or EB formation of ESC-like cells, colony-forming ability was affected and the pattern of the effects differed completely between the two ESC-like cells investigated. These results suggest that the developmental stage of extract donor embryos should be selected carefully for the culture of ESC-like cells, according to the research purpose and type of cell line.

• Journal of the Korean Society for Heat Treatment
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• v.13 no.6
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• pp.405-411
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• 2000

The effects of added elements, such as Co or Nb, on wear properties of high speed steel by powder metaliurgy(PM-HSS) had been eluminated in auther's previous paper. In addition, it is generally known that the wear properties of materials have been influenced by heat-treating conditions as well. Therefore, a study has been done to clarify the effects of heat-treating conditions on wear properties of PM-HSS. The wear tests have been performed under the same conditions as the previous paper using heat-treated PM-HSS(5%Co-1%Nb) with different quenching and tempering temperatures. The result of this paper shows that wear resistance of PM-HSS is improved with relatively high quenching temperature. However, tempering temperature is not sensitive to the wear resistance in the range of high quenching temperature. It may be deduced by the fact that the shear strength of matrix by strengthening mechanisms due to not only the quenching aging but also dispersion-hardening is improved.

• Transactions of Materials Processing
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• v.24 no.6
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• pp.425-430
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• 2015

In the current paper, the effects of initial slug design on the earring of an Al rectangular battery case manufactured by impact extrusion were studied. During impact extrusion, non-uniform metal flow between the long and the short sides of the battery case leads to earring, which is subsequently trimmed. Process parameters such as friction, aspect ratio of the battery case, the die shape and the forming temperature tend to induce earring because they cause greater non-uniform metal flow. Large aspect ratio of the battery case and high friction between slug and die can greatly affect the earring of a rectangular battery case. To make a rectangular battery case without earring, it is necessary to control metal flow uniformly during impact extrusion. One of the ways to reduce the earring is to control the metal flow of slug at the initial upsetting stage. To analyze the effects of the initial slug design on earring, FE analysis was conducted using DEFORM 3D. Two types of initial slug designs were evaluated where volume was removed along either the width or thickness directions. The results show that the initial slug design can be effective in adjusting the uniformity of metal flow.

• Archives of Pharmacal Research
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• v.20 no.6
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• pp.545-549
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• 1997

Effects of swainsonine (SW;8${\alpha}$, ${\beta}$-indolizidine-${\alpha}$, $2{\alpha}$8-triol from Locoweed) on the humoral immune responses of lipopolysaccharide (LPS) wer studied in ICR mice. Mice were divided into 4 groups (10 mice/group), and LPS was given to each mouse 1 hr after i.p. injection with 3.7 mg/kg of swainsonine, by i.p. injection twice a week for 14 days at a dose of 2 mg/kg. Humoral immune responses were evaluated by hemagglutination (HA) titer and splenic plaque forming cells (PFC). The results of this study were summarized as follows: Mice administrated each of LPS and SW showed significant enhancement of the weight ratios of spleen to body, HA titer, 2-mercaptoethanol-resistant HA(MER-HA) titer and PFC compared with those in controls. However, the LPS plus SW treatment decreased HA titer, MER-HA titer and PFC corresponding to humoral immunity, as compared with those in the mice treated with LPS alone. These findings indicated that LPS significantly enhanced humoral immune responses, but their enhancement effects were lowered somewhat by SW.

• Korea Trade Review
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• v.44 no.3
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• pp.203-226
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• 2019

This study incorporates the structural relationships between leadership styles (LS), affect climate (AC), and organizational performance (OP) in Korean export manufacturing companies with three or more overseas subsidiaries. A theoretical model is suggested with the following empirical results. First, the positive effect of engaging leadership (EL) on organizational citizenship behavior (OCB), as well as of engaging leadership, involving leadership (IL), and goal-oriented leadership (GL) on team performance (TP), proved to be significant. Second, both engaging leadership and goal-oriented leadership have significant positive effects on optimism, while involving leadership has significant negative effects on pessimism. Third, only optimism has a positive (+) effect on OCB and TP. The mediating effects were proved to be significant in two paths: one in EL->optimism->OCB and the other in EL->optimism->TP. Finally, in responding to rapid changes in the external environment of exporting companies, the engaging leadership is a key source of organizational performance by forming a favorable affect climate. Therefore, top management should recognize the role of team leaders and strengthen their leadership training. In addition, it was confirmed that leaders with emotional intelligence that can respond to the affects of members play a more important role in forming an optimistic climate in Korea export manufacturing enterprises with foreign subsidiaries.

• Steel and Composite Structures
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• v.47 no.5
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• pp.601-613
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• 2023

Numerous methods have been proposed in predicting formability of sheet metals based on microstructural and macro-scale properties of sheets. However, there are limited number of papers on the optimization problem to increase formability of sheet metals. In the present study, we aim to use novel optimization algorithms in neural networks to maximize the formability of sheet metals based on tensile curve and texture of aluminum sheet metals. In this regard, experimental and numerical evaluations of effects of texture and tensile properties are conducted. The texture effects evaluation is performed using Taylor homogenization method. The data obtained from these evaluations are gathered and utilized to train and validate an artificial neural network (ANN) with different optimization methods. Several optimization method including grey wolf algorithm (GWA), chimp optimization algorithm (ChOA) and whale optimization algorithm (WOA) are engaged in the optimization problems. The results demonstrated that in aluminum alloys the most preferable texture is cube texture for the most formable sheets. On the other hand, slight differences in the tensile behavior of the aluminum sheets in other similar conditions impose no significant decreases in the forming limit diagram under stretch loading conditions.