• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.53-60
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• 2008

The cross-sections of continuous multi-span beams sometimes suddenly increase, or become stepped, at the interior supports of continuous beams to resist high negative moments. The three-dimensional finite-element program ABAQUS (2007) was used to analytically investigate the inelastic lateral-torsional buckling behavior of stepped beams subjected to linear moment gradient and resulted in the development of design equations. The ratios of the flange thickness, flange width, and stepped length of beam are considered for the analytical parameters. Two groups of 27 cases and 36 cases, respectively, were analyzed for doubly and singly stepped beams in the inelastic buckling range. The combined effects of residual stresses and geometrical imperfection on inelastic lateral-torsional buckling of beams are considered. First, the distributions of residual stress of the cross-section is same as shown in Pi and Trahair (1995), and the initial geometric imperfection of the beam is set by central displacement equal to 0.1% of the unbraced length of beam. The new proposed equations definitely improve current design methods for the inelastic lateral-torsional buckling problem and increase efficiency in building and bridge design.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.250-265
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• 2008

Distraction osteogenesis is a well-established clinical treatment for limb length discrepancy and skeletal deformities. Appropriate mechanical tension-stress is believed not to break the callus but rather to stimulate osteogenesis. In contrast to fracture healing, the mode of bone formation in distraction osteogenesis is primarily intramembranous ossification. Although the biomechanical, histological, and ultrastructural changes associated with distraction osteogenesis have been widely described, the basic biology of the process is still not well known. Moreover, the molecular mechanisms in distraction osteogenesis remain largely unclear. Recent studies have implicated the growth factor cascade is likely to play an important role in distraction. And current reserch suggested that mechanical tension-stress modulates cell shape and phenotype, and stimulates the expression of the mRNA for bone matrix proteins. The purpose of this study is to examine the pattern of expression of growth factors($TGF-{\beta}1$, IGF-I, bFGF) and extracellular matrix proteins(osteoclacin, osteonectin) related to osteogenesis by osteodistraction of the mandible in rabbits. 24 rabbits is used for this experiment. Experimental group are gradual distraction(0.7mm, twice/day), acute distraction(1.4mm, twice/day) and control group is only osteotomized. After 5 days latency, osteotomic site is distracted for each 7 days and 3.5 days. Consolidation period is 28 days. The animal is sacrificed at the 3th, 7th, 14th, 28th. The distracted bone is examined by immunohistochemical analysis and RT-PCR analysis. The results obtained from this study were as follow : No significant difference was found on clinical examination according to distraction rate, but gradual distraction was shown to improve regenerate bone formation on radiographic and histologic examination. Growth factors and extracelluar matrix proteins expression increased in distraction group than control group. From these results, it could be stated that graudal distraction is shown to improve and accelerate bone formation and mechanical stress like distraction has considerable effects on osteogenesis related factors. And rabbit is the most appropriate animal model for further reseach on the molecular mechanisms that mediate osteodistraction. It is believed that understanding the biomolecular mechanisms that mediate distraction osteogenesis may guide the development of targeted strategies designed to improve distraction osteogenesis and accelerate bone healing.

• Herbal Formula Science
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• v.15 no.1
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• pp.163-173
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• 2007

Jeungaektang (JAT) is the herbal formula, has the effect of moistening the dryness by activating lung Qi and by nourishing Yin, has being used for dryness syndromes. Generally the herbal formulae for moistening dryness are used for exogenous or endogenous dryness syndromes. JAT has been clinically used for the treatment of endogenous dryness syndromes. It is composed of Scrophulariae Radix. Rehmanniae Radix and Liriopis Tuber. Recent studies showed that JAT has a protective effect against $CCl_{4}-induced$ hepatotoxicity and anti-inflammatory effects against ear swelling of mouse induced by Crotonis Fructus. However, the effect of JAT on the immunological activity was rarely studied. Therefore, this study evaluated the effects of JAT the regulatory mechanism of nitric oxide (NO) and cytokines in the lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. After the treatment of JAT water extract, cell viability was measured by MTT assay, NO production was monitored by measuring the nitrite content in culture medium. Cyclooxygenase-2 (COX -2) and inducible nitric oxide synthase (iNOS) were determined by immunoblot analysis, and levels of cytokine were analyzed by sandwich immunoassays. Results provided evidence that JAT inhibited the production of nitrite and nitrate ($0.1{\sim}1.0$ mg/ml), iNOS ($0.1{\sim}1.0$ mg/ml), $interleukin-1{\beta}$ ( $0.1{\sim}1.0$ mg/ml) and tumor necrosis $factor-{\alpha}$ ($0.1{\sim}1.0$ mg/ml) in RAW 264.7 cells activated with LPS. Furthermore, JAT inhibited the expression of COX-2 expression and production of prostagladin E2 ($0.1{\sim}1.0$ mg/ml). These findings suggest that JAT can produce anti-inflammatory effect, which may play a role in adjunctive therapy in Gram-negative bacterial infections.

• Journal of Embryo Transfer
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• v.24 no.3
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• pp.199-205
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• 2009

This study was carried out to investigate the effective genetic resources preservation system using the frozen boar semen. The porcine oocytes were matured for 44 hours in NCSU-23 medium with or without 10% Porcine Follicle Fluid (PFF), 0.5 ${\mu}g/ml$ porcine FSH, 0.5 ${\mu}g/ml$ equine LH, 1.0 ${\mu}g/ml$ 17 $\beta$-estradiol ($E_2$) and 10 ng/ml Epidermal Growth Factor (EGF) under mineral oil at $38.5^{\circ}C$ in humidified atmosphere of 5% $CO_2$ in air. After 44 h of culture, the oocytes were inseminated with frozen-thawed semen and fresh semen prepared with mTBM medium for 6 h. Later, set of 50 presumptive zygotes were transferred into 4-well dish (500 ${\mu}l$) of IVC medium. for embryos freezing, slow-freezing and vitrification methods were used as a cryopreservation. Differences among treatments were analyzed using General Linear Model Procedure by SAS Package (version 6.12) differences were considered significant when p<0.05. Following IVF and IVC, the rates of cleavage and blastocysts formation were significantly higher (p<0.05) in hormone supplemented group than that of hormone-free group (25.7 vs, 12.1). The development rates to cleavage and blastocysts were significantly higher in PZM-5 group than NCSU-23 group (60.3%, 46.6% vs 27.4%, 11.1%). Further improvement was achieved when PZM-5 was supplemented with FBS. Cleavage rates was significantly higher in fresh semen source group than frozen semen (66.7% vs 43.7%). However in blastocysts rates was similar two groups. Post-thaw survival rates of embryos were 1.2% and 2.2% in slow-frezing and vitrification groups, respectively. The results of our study suggest that it is still possible to improve the culture conditions and boar semen cryopreservation for enhance reproductive technology and animal genetic resources conservation.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.5
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• pp.1-12
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• 2009

The purpose of this research was to propose policy directions for the design and construction of nature-friendly park facilities (PF) in national parks. In order to do that, nature-friendliness evaluation indicators(NEIs) used in green building rating systems and related articles were reviewed. After the initial literature review was complete, NEIs for park facilities based on location, design, construction, operation, and management sectors were developed. Data was obtained through a questionnaire completed by 79 managers at 19 national parks in Korea in 2008. The answers were analyzed using descriptive statistical methods, a t-test, a multi-dimensional analysis, and a factor analysis. This research found that: 1) The results indicated that based on relative weight calculation, the location condition was evaluated as the most important; 2) The evaluation results regarding the degree of nature-friendliness of park facilities showed that location condition was ranked higher than design and construction--in addition, the evaluated values of indicators related to energy efficiency were ranked the lowest; 3) the level of nature-friendliness of shelter was given the highest level, but resting facility was the lowest level; 4) Overall, park facilities at Mt. Seorak, Mt. Odae, and Taean Coast national parks showed high levels of nature-friendliness. But park facilities at Mt. Gyeongju and Mt. Songni national parks showed low levels of nature-friendliness. The results of this research shall contribute to the establishment of tailor-made management policies, the development of detailed guidelines for increased energy efficiency and visitor satisfaction, and the preservation of ecosystems and natural resources in Korea's national parks.

• Spatial Information Research
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• v.20 no.4
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• pp.69-82
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• 2012

The purpose of this study was to identify structural properties of C.B.D and to provide direction that required for the plan and its development by analyzing land use patterns and its characteristics in the center of the city. In this study, the future planning elements and detailed land use of Seoul was analyzed, in regard to the spatial structural hierarchy and the function of downtown, by investigation of its current urban spatial structure. First, the characteristic of the land-use for merchandising facilities is that it is developed from west to east along the Jong-ro, Myungdong and Namdaemun, it shows high rate of the facilities along the horizontal axis. The large market area on this district would be the reason to the high rate of mechandising facilities. Second, the characteristic of the land-use for business facilities is that it is highly rated on the area passing through the Sejong-ro and Seoul station. The analysis result of our investigation is that the projects executed by Seoul city such as 'downtown maintenance planning' and 'downtown recreation program' strengthened functions of business and merchandising and promoted downtown shopping, leisure, tourism functions resulting activation of nearby market place and evaluated as maintaing the centrality of downtown Seoul well.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.152-163
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• 2012

At the conceptual phase of a construction project, estimated construction cost is very important as it significantly influences the owner's decision-making. Accurate cost estimating, in the early stage of a public construction project, serves as a critical factor because initial decision-making effects the final cost of a construction project. However in the cases of Korean public apartment projects, excluding a few of the public owners, there is a problem in properly estimating construction cost due to the lack of construction cost estimating system. Thus, this research developed a public apartment cost estimating system using case-based reasoning that was suggested by a previous research with 66 cases of Korean public apartment projects. Based on the system experiments involving 19 public officers and 10 cases of Korean public apartment projects, the effectiveness of the system in terms of estimation accuracy and user-friendly was confirmed. As a result, the developed system has an error range of 1.47% to 13.74% and mean of 6.15%. In addition, the system was evaluated that it could greatly improve the current estimation task of public officers. Consequently, the results of this research can be used as a foundation for a technological advance in estimating construction cost and improving the accuracy and consistency of construction cost estimation.

• Tuberculosis and Respiratory Diseases
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• v.73 no.5
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• pp.258-265
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• 2012

Background: Vitamin D can translocate a vitamin D receptor (VDR) from the nucleus to the cell membranes. The meaning of this translocation is not elucidated in terms of a role in pathogenesis of chronic obstructive pulmonary disease (COPD) till now. VDR deficient mice are prone to develop emphysema, suggesting that abnormal function of VDR might influence a generation of COPD. The blood levels of vitamin D have known to be well correlated with that of lung function in patients with COPD, and smoking is the most important risk factor in development of COPD. This study was performed to investigate whether cigarette smoke extracts (CSE) can inhibit the translocation of VDR and whether mitogen activated protein kinases (MAPKs) are involved in this inhibition. Methods: Human alveolar basal epithelial cell line (A549) was used in this study. 1,25-$(OH_2)D_3$ and/or MAPKs inhibitors and antioxidants were pre-incubated before stimulation with 10% CSE, and then nucleus and microsomal proteins were extracted for a Western blot of VDR. Results: Five minutes treatment of 1,25-(OH2)D3 induced translocation of VDR from nucleus to microsomes by a dose-dependent manner. CSE inhibited 1,25-$(OH_2)D_3$-induced translocation of VDR in both concentrations of 10% and 20%. All MAPKs inhibitors did not suppress the inhibitory effects of CSE on the 1,25-$(OH_2)D_3$-induced translocation of VDR. Quercetin suppressed the inhibitory effects of CSE on the 1,25-$(OH_2)D_3$-induced translocation of VDR, but not in n-acetylcysteine. Conclusion: CSE has an ability to inhibit vitamin D-induced VDR translocation, but MAPKs are not involved in this inhibition.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.31-44
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• 2008

The 1st phase framework data implementation of National Geographic Information Systems (NGIS) used 1:5,000 digital map with 5 years updating period which is lacking in the latest information. This is a significant factor which hinders the use of framework data. This study proposed the efficient technical method of a location based object data management and system implementation for updating framework data. First, we did an object-oriented data modeling and database design using a location based features identifier(UFID: Unique Feature IDentifier). The second, we developed the system with various functions such as a location based UFID creation, input and output, a spatial and attribute data editing, an object based data processing using UML(Unified Modeling Language). Finally, we applied the system to the study area and got high quality data of 99% accuracy and 35% benefit effect of personnel expenses compare to the previous method. We expect that this study can contribute to the maintenance of national framework data as well as the revitalization of various GIS markets by providing user the latest framework data and that we can develop the methods of a feature-change modeling and monitoring using an object based data management.

• Journal of Biosystems Engineering
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• v.8 no.2
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• pp.39-48
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• 1983

This study was performed to obtain the basic data which could be used for the modification of the manual center-burner-type rice-husk furnace into a small scale automatic type for the multi-purpose use in the farm. For this purpose, first, the utilization feasibility of the rice-husk furnace in the farm was analyzed briefly in aspects of available amount of rice-husk for the fuel, annual operation time and replaceble amount of residential heating energy with rice-husk in the farm. For the experiment a prototype furnace geared with an automatic feeding device was fabricated, and feed rate, mold size and chimney height were changed to investigate the combustion efficiency of rice-husk and thermal efficiency of the furnace. Also, optimum and limiting operational factors were observed in each treatments. The results obtained are summarized as follows. 1. If the rice-husk is intensively used for residential heating in the farm for winter season, on an average 51 percent of the total heating energy can be replaced with the rice-husk. Therefore, development of a small scale automatic rice-husk furnace was recognized to be feasible. 2. The operational condition depending on husk-feed rates was very important factor for successive steady burning operation of the given furnace. When the feed-rate was 1.5 kg/hr, the top of the burning zone should be kept at the position about 55 cm from the bottom of the combustion chamber with the periodic removal of ash (termed as steady state position), which was 18 cm above the mold waist. When the feed rates were 2.4 kg/hr and 3.0 kg/hr, the steady state position was at about 4 cm above the mold waist. 3. The mold size affected inflow rate of air into the furnace and consequently CO content in the exhaust gas. The relatively bigger mold gave positive effect on the air-inflow rate. 4. When the husk-feed rates were 1.5 kg/hr, 2.4 kg/hr, 3.0 kg/hr, the combustion efficiencies of the rice-husk were 98.5%, 97.4% and 95.0%, the thermal efficiencies of the furnace were 93.4%, 93.2% and 87.6%, and CO content in the exhaust gas were 1.21%, 1.03%, and 2.43%, respectively. The air-inflow rates were decreased with the increase of feed rates. When the amount of excess air was 30-40%, the CO content in the exhaust gas was at the minimum level. 5. When the chimney height was lowered from 260 cm to 96 cm, the air-inflow rate was slightly decreased, but the average temperature in the combustion chamber, CO content in the exhaust gas and combustion and thermal efficiencies were not changed significantly. 6. The incidental problems associated with the protytype furnace were accumulation of the ash inside the mold, accumulation of the cinder between the outer-drum of the furnace and the combustion chamber wall, and accumulation of the cinder in the chimney.