• Journal of Chest Surgery
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• v.31 no.12
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• pp.1119-1126
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• 1998

Background: In this study, we investigated the early time course of expression of the major histocompatibility(MHC) antigens, intercellular adhesion molecule-1(ICAM-1), vascular cell adhesion molecule-1(VCAM-1), interleukin-6 and the histopathological changes in the coronary arteries of cardiac allografts exchanged between inbred mice strains that differ in one loci of class I major histocompatibility antigen (B10.BR to B10.A). Material and Method: No immunosuppressive therapy was used. Both allografts and the hearts of the recipients were harvested at 7(group 1, n=6), 15(group 2, n=6), 21(group 3, n=6), and 30(group 4, n=6) days after transplantation. They were examined by immunohistochemistry, microscopy and morphometry. All allografts had contractions at the time of harvest. Result: A strong MHC class I antigen expression was present on the endothelial and medial cells of the coronary arteries in group 1 and remained unchanged in the rest of the groups. However, MHC class II reactivity was none or very little at any time. Mild to moderate ICAM-1 expression was observed on the endothelial cells, but not on the medial cells at any time by 30 days. VCAM-1 expression was strong both on the endothelial and medial cells at any time. Moderate degree expression of interleukin-6 was observed from 7 to 30 day specimens. Histopathologically, percentage of affected vessels(vessels with intimal thickening) was less than 10 % in 7 day group and increased up to 50 % at 30 days. Mean percent narrowing of the lumen of the affected vessels revealed less than 20 % at 7 days and 40 % at 30 days. The area occupied by tropomyosin positive cells in the intimal lesion, graded from 0 to 3, showed gradual increase but remained between grade 0 to 1 by 30 days. Medial integrity was also well preserved at any time. Moderate perivascular mononuclear cell infiltration was observed at 7 days and it was progressively increased upto 30 days. Recipients' heart revealed no positive immunopathologic findings. Conclusion: In this study, the early time course of progression of the transplantation vasculopathy was demonstrated in the murine heterotopic heart transplant model.

• Journal of Korean Society of Forest Science
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• v.58 no.1
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• pp.8-16
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• 1982

To study the comparison of aboveground biomass of paulownia coreana Uyeki of 6-year-old, located in Seongju of non-attacked forest and Ulsan of damaged forest by the air pollution were selected. Ten sample trees in Seongju district and seven trees in Ulsan selected taking account of DBH were measured for 16 trees in total within a $10{\times}10m$ experimental plot. The diagram of oven-dry weight distribution of stem, branch and needle for each 1m segment was constructed. The logarithmic regression equations between dry weight of each component and the two-variables, DBH and tree height, combined term were presented. IF the estimations are extended to a hectare area stand, it contains 47.49 tons of aboveground biomass in Seongju district and 19.05 tons of it in Ulsan. The annual net productions were 11.64 tons of above 2.29 kg/kg/yr in Ulsan and the efficiency of leaf to produce stem was 2.99kg/kg/yr in Seongju and 0.83kg/kg/yr in Ulsan.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.2
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• pp.121-143
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• 2010

To investigate the effect of implant types and bone resorption on the fracture characteristics. 4 types of Osstem$^{(R)}$Implant were chosen and classified into external parallel, internal parallel, external taper, internal taper groups. Finite elements analysis was conducted with ANSYS Multi Physics software. Fatigue fracture test was performed by connecting the mold to the dynamic load fatigue testing machine with maximum load of 600N and minimum load of 60N. The entire fatigue test was performed with frequency of 14Hz and fractured specimens were observed with Hitachi S-3000 H scanning electron microscope. The results were as follows: 1. In the fatigue test of 2 mm exposed implants group, Tapered type and external connected type had higher fatigue life. 2. In the fatigue test of 4 mm exposed implants group, Parallel type and external connected types had higher fatigue life. 3. The fracture patterns of all 4 mm exposed implant system appeared transversely near the dead space of the fixture. With a exposing level of 2 mm, all internally connected implant systems were fractured transversely at the platform of fixture facing the abutment. but externally connected ones were fractured at the fillet of abutment body and hexa of fixture or near the dead space of the fixture. 4. Many fatigue striations were observed near the crack initiation and propagation sites. The cleavage with facet or dimple fractures appeared at the final fracture sites. 5. Effective stress of buccal site with compressive stress is higher than that of lingual site with tensile stress, and effective stress acting on the fixture is higher than that of the abutment screw. Also, maximum effective stress acting on the parallel type fixtures is higher. It is careful to use the internal type implant system in posterior area.

• Tuberculosis and Respiratory Diseases
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• v.51 no.5
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• pp.426-436
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• 2001

Objective : This study was performed to determine the smoking status and its associated factors in military life among young Korean men to provide data for smoking prevention in military areas as a part of the health promotion program for soldiers. Methods : 1,033 infantrymen serving in 17 military units, which are located in suburbs of K city, were enrolled in this study. A questionnaire on the soldiers smoking status and other various characteristics was obtained from October 2nd to 12th, 2000. Logistic regression analysis was performed on the various variables in order to determine the factors related to smoking. Results : 1) 830(80.3%) out of 1033 subjects had smoked cigarettes and 759 persons(73.4%) were regular smokers. 2) Among the 734 soldiers who started smoking before their military service, 714 soldiers(97.2%) continued to smoke after, while 45 soldiers(15.0%) among the 299 non-smokers started smoking after joining the army. 3) Through the logistic regression analysis. the education level. specialty in the army. smoking amongst the friends they met before military service, smoking amongst soldiers in the army. dating girl friends, drinking, satisfaction with their army lives and the presence of convenient smoking places at the barracks were significant factors related to the prevalence of smoking in soldiers. Conclusion : The factors related with incidence of smoking in the army are the complicated interactions among the individuals personal background, general characteristics of the soldier and the special environment in the barracks. Therefore, to improve national soldiers' health, an active non-smoking campaign and education should be pushed to discourage smoking in the barracks.

• Journal of Wetlands Research
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• v.1 no.1
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• pp.29-44
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• 1999

Vegetation structure and distribution of the vascular hydrophytes and hygrophytes, and the growth pattern, standing crop and amounts of nutrient uptake by Salix species were investigated in the upper stream wetlands of the Namgang-Dam, Chinju-city, Gyeongsangnam-do, Korea from April to November in 1997. The flora was composed of 43 hydrophytes and 241 hygrophytes, or total 284 vascular plants. The life forms of the hydrophytes were classified as 27 kinds of emergent plants, 4 floating-leaved plants, 3 free-floating plants, and 9 submersed plants. In the herb layer, the dominant species was Persicaria hyciropiper, and the ranges of the species diversity indices (H'), equitabilities, (J') and community similarity indices (CCs) were 1.59~1.89, 0.87~0.96, and 0.35~0.83, respectively. In the shrub and subtree layers, 17 kinds of Salix species were supposed to the pioneer plants at the early stage of the succession. The number of branches per main stem of Salix species was 5.0. The DBH class-frequency histograms of Salix species were the reverse J type, and the natural regeneration of the Salix community was expected. Basal area of Salix species per square meter was $24.87cm^2$. Volume of Salix species per square meter was $12,008cm^3$ and total phytomass of the Salix species was estimated as 12,894 ton. Biomass distribution of Salix species in the stem, the branch and twig, and the leaf was 64.1%, 28.1%, and 7.8%, respectively. The amounts of nitrogen and phosphorus absorbed by Salix species were 68,022 and 19,823 kg. It was recommended that application and conservation of the wetland and other counterplans are indispensable to reduce the adverse effects of water pollution and to preserve the wetland ecosystem.

• Journal of Yeungnam Medical Science
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• v.7 no.1
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• pp.81-93
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• 1990

The author fractographically analyized the cause of metal failure(the first time this procedure has been used for this metal failure)and also analyized it clinically. In this study, I selected eight cases which have been analyized fractographically. In all these cases, the analysis was done after treatment of metal failure of implants internally fixed to femur shaft fractures at the Department of Orthopedic Surgery, Yeung-Nam University Hospital during the six year period from May 1983 to September 1989. 1. Metal failure occured in five dynamic-compression plates, one Jewett nail, one screw in Rowe plate, and one interlocking nail. 2. The clinical cause of metal failure was deficiency of medial butress in five cases, incorrect position of implant in one case, and incorrect selection of implant in two cases. 3. The time interval between internal fixation and metal failure was four months in one case, between five months to twelve months in six cases, three years in one case. 4. The fractographically analytical cause of metal failure was ; first, impact failure, one case, second, fatigue failure, six cases, machining mark(stress liser), four cases type : low consistent cyclic fatigue failure irregular cyclic fatigue failure third, stress corrosion crack, one case. 5. 316L Stainless Steel has good resistance to corrosion. However, when its peculiar surface film is destroyed by fretting, it shows pitting corrosion. This is, perhaps, the main cause of metal failure. 6. It is possible that mechanical injury occured in implants during the manufacturing of implants or that making a screw hole is the main cause of metal failure.

• Journal of Intelligence and Information Systems
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• v.27 no.3
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• pp.75-94
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• 2021

The low birth rate and shortened military service period are causing concerns about selecting excellent military officers. The Republic of Korea entered a low birth rate society in 1984 and an aged society in 2018 respectively, and is expected to be in a super-aged society in 2025. In addition, the troop-oriented military is changed as a state-of-the-art weapons-oriented military, and the reduction of the military service period was implemented in 2018 to ease the burden of military service for young people and play a role in the society early. Some observe that the application rate for military officers is falling due to a decrease of manpower resources and a preference for shortened mandatory military service over military officers. This requires further consideration of the policy of securing excellent military officers. Most of the related studies have used social scientists' methodologies, but this study applies the methodology of text mining suitable for large-scale documents analysis. This study extracts words of discriminative characteristics from the Republic of Korea Air Force Non-Commissioned Officer Applicant cover letters and analyzes the polarity of pass and fail. It consists of three steps in total. First, the application is divided into general and technical fields, and the words characterized in the cover letter are ordered according to the difference in the frequency ratio of each field. The greater the difference in the proportion of each application field, the field character is defined as 'more discriminative'. Based on this, we extract the top 50 words representing discriminative characteristics in general fields and the top 50 words representing discriminative characteristics in technology fields. Second, the number of appropriate topics in the overall cover letter is calculated through the LDA. It uses perplexity score and coherence score. Based on the appropriate number of topics, we then use LDA to generate topic and probability, and estimate which topic words of discriminative characteristic belong to. Subsequently, the keyword indicators of questions used to set the labeling candidate index, and the most appropriate index indicator is set as the label for the topic when considering the topic-specific word distribution. Third, using L-LDA, which sets the cover letter and label as pass and fail, we generate topics and probabilities for each field of pass and fail labels. Furthermore, we extract only words of discriminative characteristics that give labeled topics among generated topics and probabilities by pass and fail labels. Next, we extract the difference between the probability on the pass label and the probability on the fail label by word of the labeled discriminative characteristic. A positive figure can be seen as having the polarity of pass, and a negative figure can be seen as having the polarity of fail. This study is the first research to reflect the characteristics of cover letters of Republic of Korea Air Force non-commissioned officer applicants, not in the private sector. Moreover, these methodologies can apply text mining techniques for multiple documents, rather survey or interview methods, to reduce analysis time and increase reliability for the entire population. For this reason, the methodology proposed in the study is also applicable to other forms of multiple documents in the field of military personnel. This study shows that L-LDA is more suitable than LDA to extract discriminative characteristics of Republic of Korea Air Force Noncommissioned cover letters. Furthermore, this study proposes a methodology that uses a combination of LDA and L-LDA. Therefore, through the analysis of the results of the acquisition of non-commissioned Republic of Korea Air Force officers, we would like to provide information available for acquisition and promotional policies and propose a methodology available for research in the field of military manpower acquisition.

• Journal of the Korean Orthopaedic Association
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• v.56 no.3
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• pp.234-244
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• 2021

Purpose: To date, studies of firearm and explosive injuries in the Korean military have been limited compared to its importance. To overcome this, this study examined the characteristics of musculoskeletal damages in soldiers who have suffered firearm and explosive injuries over the past four years. Materials and Methods: From January 2015 to July 2019, military forces who had suffered musculoskeletal injuries from firearms or explosive substances were included. The medical records and radiographs were reviewed retrospectively, and telephone surveys about Short Musculoskeletal Functional Assessment (SMFA) for this group were conducted. To compare the functional outcomes, statistical analysis was performed using a t-test for the types of weapons, and ANOVA for others. Results: Of the 61 patients treated for firearms and explosives injuries, 30 patients (49.2%) were included after undergoing orthopedic treatment due to musculoskeletal injury. The average age at injury was 26.4 years old (21-52 years old). The number of officers and soldiers was similar. Eleven were injured by gunshot and 19 by an explosive device. Sixteen were treated in the Armed Forces Capital Hospital and 10 at private hospitals. More than half of the 16 patients (53.3%) with a fracture had multiple fractures. The most common injury site was the hand (33.3%), followed by the lower leg (30.0%). There were 14 patients (46.7%) with Gustilo-Anderson classification 3B or higher who required a soft tissue reconstruction. Fifteen patients agreed to join the SMFA survey for the functional outcomes. Between officers and soldiers, officers had better scores in the Bother Index compared to soldiers (p=0.0045). Patients treated in the Armed Forces Capital Hospital had better scores in both the Dysfunction and Bother Index compared to private hospitals (p=0.0008, p=0.0149). Conclusion: This is the first study to analyze of weapons injuries in the Korean military. As a result of the study, the orthopedic burden was high in the treating patients with military weapon injuries. In addition, it is necessary to build a military trauma registry, including firearm and explosive injuries, for trauma treatment evaluation and development of military trauma system.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.1
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• pp.7-16
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• 1995

In countries where confucianism is popular, it is extremely hard to get fresh cadaver bone for allograft. Therefore in Korea, the reimplantation of resected autoclaved autogenous bone segments has been increasingly performed for limb reconstruction of extremities with malignancies. To preserve the bone morphogenetic protein and mechanical strength of heated bone, many studies have reported that pasteurization of bone is far better than autoclaving over $100^{\circ}C$. Based on this assumption, replacement with a pasteurized autogenous bone graft after resection of a malignant bone tumor was deemed feasible for reconstruction. However, little is known about how high a temperature and how much time for pasteurization is needed to make tumors completely necrotic and to maintain the mechanical strength of bone. Consequantly, experimental studies were carried out to test heat conductivity of human bone and torsional strength of porcine tibia after pasteurization. First, two pairs of human proximal tibia and distal femur were used. We used T-type thermocoples to check core temperature of the bone and a computerized data acquisition system to record results. Without reaming of the medullary cavity, in a $60^{\circ}C$-thermostatic saline tub, it took 32 minutes and 50 seconds to raise the core temperature of human proximal tibia from $20^{\circ}C$ to $58^{\circ}C$, and 30 minutes for distal femur. In a $80^{\circ}C$ saline tub, it took 12 minutes and 50 seconds for proximal tibia, and 11 minutes and 10 seconds for distal femur. In contrast, using porcine tibia whose cortical thickness is similar to that of human tibia, after reaming of the medullary canal, it took less than 3 minutes and 30 seconds in a $60^{\circ}C$ saline tub, less than 1 minute and 45 seconds in a $70^{\circ}C$ tub, and less than 1 minute in a $80^{\circ}C$ tub to elevate core temperature from $20^{\circ}C$ to $58^{\circ}C$. Second, based on data of the heat conductivity test, we compared the torsional strength before and after pasteurization. Twenty matched pairs of porcine tibia were used, The left one was used as a non-heated control group and the right one as a pasteurized experimental group. Wighout reaming of the medullary cavity, there was no statistical difference in torsional strength between the pasteurization of the $60^{\circ}C$-35minute and of $80^{\circ}C$-15minute. With reaming, we also found no statistical difference among pasteurization of $60^{\circ}C$-15 minute, of $70^{\circ}C$-15 minute, and of $80^{\circ}C$-15 minute groups. In conclusion, reaming of the medullary canal is very helpful in saving pasteurization time. And, in a $60^{\circ}C$ saline tub, no significant weakness in torsional strength occurs with pasteurization of the bone for up to 35 minutes. Also no significant weakness in torsional strength occurs with an exposure of 15 minutes to the $80^{\circ}C$ saline tub.

• Journal of Yeungnam Medical Science
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• v.20 no.1
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• pp.28-35
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• 2003

Purpose: To evaluate physeal remodeling after internal fixation of slipped capital femoral epiphysis, We performed a retrospective review of the medical records and radiographs of 14 children (17 cases) who had had slipped capital femoral epiphysis. Materials and Methods: We reviewed 14 patients who had slipped capital femoral epiphysis. They were divided two groups. Group I were in situ pinning with single screw and group II were corrective osteotomy with multiple pinning. We identified physeal remodeling camparing with their preoperative, postoperative and last follow-up radiographs with measuring physeal-shaft angle. Results: Early closure of the physis was observed in 6 cases among 14 patients (17 hips). Compared with their postoperative radiographs, the last follow up radiographic study revealed that physeal remodeling was observed in 4 patients (4 hips) at group I (mean, $7.8^{\circ}$), in 2 patients (3 hips) at group II (mean, $10.7^{\circ}$). Conclusion: In this study, physeal remodeling was observed in 4 patients (4 hips) in group I and 2 patients (3 hips) in group II. The incidence of physeal remodeling was related with degree of epiphyseal slippage, and age was not related with physeal remodeling potential.