• Journal of the Korean Wood Science and Technology
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• v.35 no.3
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• pp.79-87
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• 2007

This study investigated the effects of lacquer-finishing to prevent discoloration of coloring chestnut wood coated with natural dyes from deteriorating factors such as lights (indoor, 500 lux and outdoor, 50,000~70,000 lux), acid, alkali, and heat through measurement of color difference. Lacquer-finishing coating contributed to protection of intrinsic color of the natural dyeing woods in spite of severe treatment. In particular, dyeing liquor with alkali pH played a great role in prevention of light discoloration.

• Journal of Preventive Medicine and Public Health
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• v.38 no.1
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• pp.38-44
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• 2005

Objective : To compare the mortality rate of Korean medical doctors to that of the general Korean population for the period 1992-2002. Methods : The membership records of the Korean Medical Association were linked to the 1992-2002 death certificate data of Korea s National Statistical Office using 13-digit unique personal identification numbers. The study population consisted of 61,164 medical doctors with a follow-up period of 473,932 person-years. Standardized mortality ratios(SMRs) were calculated to compare cause-specific mortality rates of medical doctors to those of the general population. Results : We confirmed 1,150 deaths at ages from 30 to 75 years from 1 January 1992 to 31 December 2002. The SMR for all-cause of death was 0.47(95% CI : $0.44{\sim}0.50$). The SMRs for smoking-related diseases such as cerebrovascular accidents and chronic obstructive pulmonary disease were smaller than the SMR of all-cause of death. However, the SMRs for colorectal and pancreatic cancers were not significantly lower than those of the general population. Transport accidents and suicides accounted for 72% (94 of 131) of external causes of death. The SMR for suicide was 0.51 (95% CI : $0.38{\sim}0.68$). Conclusions : The mortality rate of South Korean medical doctors was less than 50% that of the general population of South Korea. Cause-specific analysis showed that mortality rates in leading causes of death were lower among medical doctors although differences in mortality rates between medical doctors and the general population varied with the causes of death. These health benefits found among medical doctors may be attributable to the lower level of health damaging behaviors (e.g., lower smoking rates) and better working conditions.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.100-103
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• 2008

Purpose: Eccrine porocarcinoma is a very rare, potentially fatal tumor which arises from the intraepidermal portion of the eccrine sweat ductal apparatus. It does not have a characteristic clinical feature but does have a high incidence of metastasis. It may be developed de novo or in a preexisting benign eccrine poroma. It usually affects older people and is located most commonly on lower extremities. We report a rare case of eccrine porocarcinoma which developed on the back without metastasis. Methods: The patient was a 94-year-old woman who showed a painful, ulcerated, dark brown colored polypoid $3.5{\times}3.0cm$ sized mass on the back for 3 years. We totally excised the lesion including normal tissue. Results: After wide excision of the lesion, pathologist reported an eccrine porocarcinoma. Histopathologic findings reveal that the classic type of eccrine gland carcinoma, eccrine porocarcinoma. Immunocytochemical studies showed a positive reactivity to anti-EMA antibody and anti-CEA antibody. Conclusion: Authors experienced a rare case of primary eccrine porocarcinoma on the back. Because of the propensity to develop local recurrence, wide excision of the primary tumor with histologic confirmation of negative margins represents the only curative treatment regimen for eccrine porocarcinoma.

• Journal of Korean Society of Steel Construction
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• v.22 no.3
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• pp.253-260
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• 2010

The purpose of this paper is to investigate the behavior of concrete-filled tube columns for footing connections. Eight specimens were tested to investigate such structural behavior according to the column base type. The specimens consisted of concrete-filled steel tube columns (or bare steel tube columns), reinforced concrete footings, and base plates (or stud connectors). The specimens were subjected to lateral cyclic load. The cyclic load was applied according to a predetermined strength sequence. The results of the experiment indicated that the flexural strength of the stud-connector- type column base is higher than that of the base-plate-type column base. The structural behavior of the concrete-filled tube column base was similar to that of the bare steel column base.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.6
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• pp.106-112
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• 2015

Many researchers have proposed analytical methods to measure the adsorption of di-sulpho fluorescent whitening agents (D-FWAs), but practical methods for D-FWA utilization in an actual paper mill have not been established. In particular, the D-FWA adsorption behavior must be monitored in paper mills to ensure the effective use of D-FWAs. This study used the zeta-potential of pulps as an indicator of the adsorption behavior of a D-FWA. We identified the relationship between the actual adsorption of the D-FWA and the zeta-potential of the pulps as a function of D-FWA addition. zeta-potential measurements were then used to analyze the D-FWA adsorption behavior under different conditions of pulp type, conductivity, and pH. The actual adsorption of a D-FWA was proportional to the ${\Delta}zeta-potential$ of the pulps (i.e., the difference between the zeta-potential of a pulp containing no D-FWA and one containing the D-FWA). The ${\Delta}zeta-potential$ of the pulps was therefore adopted for adsorption analysis. A higher adsorption of the D-FWA was observed onto Hw-BKP than onto Sw-BKP because of the shorter fiber length and higher fines content of Hw-BKP. A high conductivity and an acidic pH decreased the D-FWA adsorption because of direct effects of high ion concentrations and low pH on the D-FWA solubility. Therefore, a D-FWA must be added to Hw-BKP under low conductivity conditions and at neutral or alkaline pH to optimize the D-FWA adsorption.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.2
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• pp.16-23
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• 2011

This study was carried out to develop the printing Hanji made of mixed raw materials with mulberry bast fibers and alternative plant fibers such as bamboo, soybean stalks, pepper stalk and sea tangle. All alternative plant fibers were produced by the kraft pulping method with 2 stages of bleaching, and used to prepare the modified traditional paper, Hanji for printing purpose. Printing quality of modified Hanji was analyzed by measuring area and Formcircle of halftones and comparing a letter shape printed on paper. The Hanji made of 60% of mulberry bast fibers and 40% of bamboo bleached kraft pulp showed the best printing quality with the smallest area and the largest Formcircle in all modified Hanji. Through the image analysis of form circles of the letters printed on the Hanji, it could also be confirmed that the best printability of the modified Hanji was made using bamboo fibers.

• Journal of Chest Surgery
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• v.31 no.1
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• pp.59-65
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• 1998

Atrial fibrillation is the most common of all cardiac arrhythmias. It is associated with significant morbidity and mortality and is frequently resistant to medical therapy. On the experimental and clinical study, the presence of macroreentrant circuits and the absence of either microreentrant circuits or evidence of atrial automaticity suggests that atrial fibrillation should be amenable to surgical ablation. The results of the maze III procedure are associated with a higher incidence of postoperative sinus rhythm, improved long-term sinus node function, fewer pacemaker requirements, less arrhythmia recurrence, and improved long-term atrial transport function. We had experienced 4 patients with chronic atrial fibrillation. For the first time, Hioki procedure had been performed in the first patient with ASD and atrial fibrillation, regular sinus rhythm showed on postoperative EKG, but junctional rhythm and bradycardia developed postoperative 3 years. The maze III procedure for the rest with mitral valvular disease and atrial fibrillation had been done, followed by regular sinus rhythm for 2 patients and atrial fibrillation for 1 patient, managed with amiodarone, on immediate postoperative state. Echocardiogram documented good contraction of right atrium and hardly contraction of left atrium for 2 patients with regular sinus rhythm postoperative 3 months.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.130-138
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• 2015

In this study, to examine the application of cast-in-place of high-flowable and high-strength concrete, an experimental study on the lateral pressure of a formwork was preformed. The experiment specimens, which have different casting height and casting speed were prepared. The lateral pressure and the change of temperature from test specimens were obtained. The maximum lateral pressure was shown to lateral pressure of fresh concrete. Immediately after placing, the lateral pressure starts to decrease and, after 12 hours, it showed a stabilization. The decreased tend of the lateral pressure was similar with normal-strength concrete, which appears stabilization after 3~4 hours from casting completion. The more casting speed is fast, the more maximum lateral pressure is high, but pressure reduction with the lapse of time was nearly similar. In addition, it was found that there was no direct relation between the hydration heat and the lateral pressure reduction.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.5
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• pp.36-42
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• 2000

The increasing application of power electronic equipment 'especially (ASDs: adjustable speed drives)] on distribution systems has led to a growing concern for harmonic distortion and the resulting impacts on system equipment and operations. Therefore, harmonic studies have become an important aspect of power system analysis and design in recently years. Computer simulations which is related harmonic are used to quantify the distortion in voltage waveforms in a power system. Many digital computer programs are available for harmonic analysis. In frequency spectrum analysis, Simulation using SuperHarm program is superior to simulation using others. Therefore, Computer simulation using SuperHarm program is one of the effective ways to assess the harmonic effects of ASDs. The purpose of this study is to calculate the quantity of harmonic voltage by varying the ASD side load and to design the optimal harmonic filter for the elimination of harmonics.

• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.386-390
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• 2002

The opening phenomenon of mature female cone in Pinus densiflora aye observed from the anatomical characteristics. The differentiation of tissue in young cone aye not complete and are going on. In the green cone as large as the adult cone, shrink-age rate of vascular strands and sclerenchyma aye 1.0∼1.5％ and 14.0∼16.0% respectively. The end parts of cone scales are composed of the parenchymatous cell and sclerenchyma. The middle parts in cone scales are composed of the sclerenchyma and vascular strands with the same thickness and more thin than the thickness of the end part and basal one. But thickness of sclerenchyma which compose of scale prop in the basal part of cone scale aye twice than that of vascular strand. In mature cone, the opening phenomenon of the pine cone results from the difference of shrinkage rate between vascular bundle and sclerenchyma. Especially, opening of cone scales are due to larger shrinkage rate of sclerenchyma than vascular strands in the basal part of cone scale.