• The Journal of Economics, Marketing and Management
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• v.9 no.5
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• pp.15-25
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• 2021

Purpose: In the Korean railway infrastructure process, contractors and operators are involved at a later stage, which results in significant inefficiency. This study examines the benefits of early stakeholder involvement in Korean railway infrastructure projects and provides practical guidelines. Design, data and methodology: Literatures and foreign cases are analyzed. Building on the new product development model, we derive propositions explaining the relationship between early stakeholder involvement and the performance of Korean railway infrastructure project. Results: Major propositions include that early involvement of contractor has a positive effect on the project performance by shortening the infrastructure construction period and that early involvement of railway operator has a positive effect on the project performance by improving the effectiveness of railway infrastructure. Four requirements for the success of early stakeholder involvement are addressed. Conclusions: This study suggests that early stakeholder involvement shortens the construction period and improves railway infrastructure effectiveness. Academic contribution is to present the framework on railway infrastructure projects as holistic interactions among stakeholders. Practical contribution is to provide railway policy makers and other business practitioners with policy guidelines to improve railway infrastructure project process and to recommend an open access to relevant data.

• Biomolecules & Therapeutics
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• v.27 no.5
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• pp.466-473
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• 2019

Angelica gigas has been used as a Korean traditional medicine for pain relief and gynecological health. Although the extracts are reported to have an anti-inflammatory property, the bioactive compounds of the herbal plant and the effect on T cell responses are unclear. In this study, we identified decursinol angelate (DA) as an immunomodulatory ingredient of A. gigas and demonstrated its suppressive effect on type 17 helper T (Th17) cell responses. Helper T cell culture experiments revealed that DA impeded the differentiation of Th17 cells and IL-17 production without affecting the survival and proliferation of CD4 T cells. By using a dextran sodium sulfate (DSS)-induced colitis model, we determined the therapeutic potential of DA for the treatment of ulcerative colitis. DA treatment attenuated the severity of colitis including a reduction in weight loss, colon shortening, and protection from colonic tissue damage induced by DSS administration. Intriguingly, Th17 cells concurrently with neutrophils in the colitis tissues were significantly decreased by the DA treatment. Overall, our experimental evidence reveals for the first time that DA is an anti-inflammatory compound to modulate inflammatory T cells, and suggests DA as a potential therapeutic agent to manage inflammatory conditions associated with Th17 cell responses.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.263-270
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• 2017

The precast concrete (PC) structure has been preferred for reasons of shortening the construction time and securing the quality and, in particular, it has a cost saving effect in case of long span and heavy loaded structure with high floor height. Most engineers take it for granted to install the plant produced PC members. Researchers in several papers have argued that slander PC members such as columns and girders can be cost-effective if in-situ production is possible, while ensuring quality equal to or better than in-plant production. However, this argument is not officially accepted because objective verification has not been done. Therefore, the purpose of this study is to experimentally conduct in-situ production of PC members to verify the above claim. For this study, a storage building with long span and heavy loaded structure with high floor height was selected as a case study site. For the site, most of the PC members were supplied from the plant, and some of the columns were produced in the site for this study. As a result, it has been confirmed that it has a cost saving effect of 20% while having superior quality to plant-produced PC columns.

• Computational Structural Engineering
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• v.9 no.3
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• pp.199-207
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• 1996

When an initially straight thin cylinder is bent, there is a tendency for the cross section to flatten. This phenomenon was investigated by L.G. Brazier in 1927 and is called "Brazier Effect" or "Brazier Theory". The main characteristic is the reduction of carrying capacity due to the decrease of bending stiffness by shortening of thickness with the increase of external load. And the relationship of curvature-bending moment becomes a soft spring type as shown in Fig.2. In this paper, the Brazier theory on plate type structures is investigated from the following view points : (1) What is the Brazier effect? (2) the reason of the occurrence of the Brazier effect in plate type structures by using beam model and (3) factors which cause the brazier effect.

• The Korean Journal of Pharmacology
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• v.13 no.2
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• pp.11-17
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• 1977

The effects of varing concentrations of extracellular potassium on the positive inotropic actions of Aconiti tuber butanol fraction and ouabain were studied on isolated left atrium of rat. The patterns of active tension increment, such as time to peak and total duration of tension development, was contrasted in Aconiti tuber butanol fraction to ouabain. Ouabain did not induce significant shortening in time to peak and total duration of tension development, but Aconiti tuber produce significant shortening. The isometric tension and peak dF/dt were not significantly different at the range of extracellular potassium concentration $2mEq{\sim}10mEq$ per. liter in control studies. The ouabain-induced increase in active tension and peak dF/dt at 2mEq. per. liter potassium concentration was significantly different from that of 6mEq or 10mEq. per. liter, but there was no difference between 6mEq and 10mEq. per. liter. but Aconiti tuber is not. In contrast to ouabain, Aconiti tuber butanol fraction did not show potassium dependent positive inotropic effect. It produced almost same increment of tension and peak dF/dt at all the concentration of extracellular potassium concentrations in this experiment.

• Journal of the Korean Applied Science and Technology
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• v.5 no.2
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• pp.39-54
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• 1988

The effects of exercise and selenium added high fat diet on edurance and serum lipid components were studied in rats. A total of 72 male Sprague-Dawley ($150{\pm}35g$, body weight) were divided into trained group and untrained group and were bred for 7 weeks. Each group had 6 different dietary subgroups; namely, basal diet, 20％ shortening and 20％ soybean oil subgroup and selenium (0.01mg％) added each subgroups. Exercises of 8-min treadmill running and 10-min swimming were given to the trained group every other day during the experimental period while only treadmill running was given to the untrained group during the last week. The amounts of food intake, changes in body weight and endurance were determined once a week and serum lipid components were measured before and after experimental period. Following are the results obtained : 1) The untrained group took a slightly larger amount of food than that in the trained group. The food efficiency is, however, higher in the trained group. Body weight increased more in untrained group, while high fat diet resulted in greater increment in body weight than that in normal diet groups. 2) The trained group showed remarkably longer endurance than the untrained group and selenium added high fat diet enhanced the effect. 3) The trained group showed lower blood level of T-chol., TG and TG/PL than the untrained group. All the other blood values of HDL-chol., PL, MDL-chol./T-chol., HDL/LDL and A/G ratio were higher in trained group. 4) Soybean oil added dietary groups exibited lower blood levels of T-chol., TG, TG/PL and A/G than those in shortening added dietary groups. On the contrary, the former groups showed higher blood HDL-chol., PL., HDL, HDL-chol. and HDL/LDL ratio than those of soybean oil added dietary groups. 5) $LDH_5$ was the most abundant one among serum LDH isozymes. The electrophoretic pattern of serum LDH isozymes was not changed by exercise training and selenium added high fat diet. 6) Exercise training lowered blood GOT and TBA. These effects were enhanced by soybean oil added diets. From the above results it was concluded that a regular and long term exercise training as well as a small amount of selenium added high fat diet result in reduction of body weight and TBA and improve dietary efficiency and physical endurance in rats.

• Journal of Chest Surgery
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• v.32 no.4
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• pp.353-357
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• 1999

Background: Mitral valve replacement(MVR) with chordal preservation in patients with mitral vlavular disease has been proven to be beneficial for left ventricular function and for reduction of postoperative complication. Material and Method: From January 1995 to July 1996, the early postoperative results of mitral valve replacement were compared between 20 patients who underwent chordae resection(classic MVR group) and 10 patients who underwent chordae preservation(preservation MVR group) in the Department of Thoracic and Cardiovascular Surgery, Chunbuk National University Hospital. Result: There was no significant difference between the two groups in age, sex, NYHA functional class, cardiothoracic ratio, echocardiographic finding, cardiopulmonary bypass time and aortic cross clamping time. The difference between preoperative and postoperative cardiothoracic ratio after 3 months was not statistically significant. At echocardiographic left ventricular evaluation, ejection fraction and fractional shortening decreased slightly in the preservation group then preoperative value (p=0.47, p=0.12), however, decreased significantly in the classic MVR group(p=0.03, p=0.04), and were statistically significant between the two groups(p=0.03, p=0.02). Conclusion: We conclude that MVR with chorda preservation seems to have a beneficial effect on postoperative left ventricular performance in mitral valve disease than the classic MVR.

• The Journal of Pediatrics of Korean Medicine
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• v.29 no.3
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• pp.54-64
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• 2015

Objectives : This study was to investigate the anti-oxidative and anti-inflammatory effect of Lonicera japonica water extracts (LE) on Ulcerative Colitis Induced by DSS (Dextran Sulfate Sodium) in Mice. Methods : Colitis was induced by DSS in Balb/c mice. The sample group was divided into three. The mice in control group were not inflammation-induced. The pathological group was composed of untreated colitis elicited mice. The experimental group was administered Lonicera japonica water extracts (LE) after colitis elicitation. The effects on ulcerative colitis were evaluated the anti-oxidant effect, inhibition of COX-2 mRNA expression, the morphological change of colonic mucosa, decrease effect of HSP 70 and COX-2 in mucosa. Results : The SOD ability of LE was dose-dependently increased and the LPS-induced COX-2 mRNA expression of LE was dose-dependently decreased. LE showed the protective effects on DSS-induced experimental colitis. LE inhibited shortening of colon length, the hemorrhagic erosion in colonic mucosa. LE also showed the decrease effect for HSP70 and COX-2 in mucosa. Conclusions : The current results demonstrate the clinical utility of LE in traditional medicine and indicate the possible treatments for ulcerative colitis from natural products. Further investigations for exact mechanisms will be needed.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.122-122
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• 2019

Protaetia brevitarsis (PB) extracts has been traditionally used as medicinal stuff to treat blood stasis, occlusion of menstruation, tetanus and liver cancer in Asian countries (Korea, Japan, China, Taiwan, India and Myanmar). Especially, Donguibogam, which is traditional korean medicinal book, described the PB extracts as traditional medicine to treat hepatic diseases and vascular disorders. The PB extracts has been considered as highly nutritional food. The major constituents of PB extracts are rich in protein, healthy fats, iron, calcium. Recent studies announced that PB extracts has hepatoprotective effect and anti-microbacterial effect. However, the effect of PB on ulcerative colitis has not been uncovered yet. The aim of this study was to examine the anti-inflammatory effect of PB extracts in dextran sulfate sodium (DSS)-induced colitis mice model. Cytotoxicity of PB was determined by MTT assay and the antiinflammatory effect of PB extract was investigated by measuring nitric oxide (NO) production. PB extracts did not show any cytotoxicity. AIso, PB extracts supressed NO production in LPS-stimulated mice peritoneal macrophages. To determine whether PB could be an effective treatment on ulcerative colitis, DSS was administered in BALB/c mice for 10 days. PB extract significantly improved the clinical signs of DSS-induced UC, including body weight loss, colon length shortening, and disease activity index increase, with histological markers of colon injury. These findings indicated the possibility of PB as a therapeutic agent on ulcerative colitis.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.210-216
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• 2022

The army is concerned about the decrease in enlistment resources due to the low birth rate and the weakening of military combat power due to the shortening of the military service period. Now, the military's quantitative growth is no longer limited and it is a time for qualitative growth. To this end, the Army has been applying the Israeli learning method Havruta to recruit training to improve the quality of training since 2019. After applying Havruta, several scholars have studied the effect of recruit training applying Havruta. As a result, it was verified that recruit training applying Havruta improves the inner motive, creativity, and military service value of trainees. This study investigated how trainees' inner motive, creativity, and military service value affect their satisfaction and achievement. In addition, it was studied whether the effect of recruit training applied with Havruta on achievement differs according to the educational background (high school graduate or higher) and military family (professional soldiers within 4th degree) of the trainees. To this end, a survey was conducted on 472 recruits, and the structural relationship between each variable and the moderating effect were analyzed using the structural equation model. As a result of the study, military service value did not affect training satisfaction. Also, there was a difference in the effect of creativity on training satisfaction according to the educational background of new recruits, and there was a difference in the effect of military service value on training satisfaction and training achievement according to military family members. The purpose of this study is to contribute to the improvement of the army's recruit training development plan and effective training system.