• Journal of Life Science
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• v.20 no.4
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• pp.561-571
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• 2010

Colon cancer is one of the most common malignancies in the western world and the second leading cause of cancer death in Korea. Epidemiology studies have shown a reduced incidence of colon cancer among populations consuming a large quantity of ${\omega}3$-polyunsaturated fatty acids (${\omega}3$-PUFA) of marine origin. Recently, it has been found that ${\omega}3$-PUFA has an antineoplastic effect in several cancers. This study was designed to investigate the mechanism of the anti-invasive effect of ${\omega}3$-PUFA in colon cancer. ${\omega}3$-PUFA, docosahexaenoic acids (DHA) and eicosapentaenoic acid (EPA) treatment resulted in a dose-dependent inhibition of cell growth in SW480 human colon cancer cells. In contrast, arachidonic acid (AA), a ${\omega}6$-PUFA, exhibited no significant effect. This action likely involves apoptosis, given that DHA treatment increased apoptotic cells in TUNEL assay. Moreover, invasiveness of SW480 cells was inhibited following treatment of DHA in a dose-dependent manner; in contrast, AA had no effect. The levels of MMP-9 and MMP-2 mRNA decreased after DHA pretreatment. MMP-9 and MMP-2 promoter activities were also inhibited by DHA treatment. The levels of NF-kB and p-IkB protein were down-regulated by DHA pretreatment in a dose dependent manner. In addition, DHA inhibited NF-kB promoter reporter activities. These findings suggest that ${\omega}3$-PUFA may inhibit cancer cell invasion by inhibition of MMPs via reduction of NF-kB in colon cancer. In conclusion, ${\omega}3$-PUFA could be used for chemoprevention and treatment of human colon cancer.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.6
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• pp.327-340
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• 2017

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

• Journal of Preventive Medicine and Public Health
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• v.32 no.3
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• pp.421-426
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• 1999

Objectives: An outbreak of dermatosis occurred at a city gas manufacturing factory in Pohang in Aug, 1998. The authors conducted a study to find the cause and prevent the dermatosis, Methods: We conducted a questionnaire survey of 73 workers in the factory twice, once or Aug. 14th and then Sept. 11th, 1998. Also, a dermatologist examined their skin lesions. We suspected ants as the cause, so we collected them for identification. Results: Twelve cases of dermatosis were identified with an attack rate of 16.4%. The attack rates were not different by age, educational level or tenures. The attack rates were 66.6% among production workers, 2.0% among clerical workers, 16.7% among tank trailer drivers and 0% among guards. The attack rate among production workers was significantly higher than that of the others (<0.01). There were no histories of the same dermatosis for the past one year. Histories of other skin diseases and allergies were very rare in both cases with skin diseases and control. Multiple, pruritic, rice-grained to bean sized erythemafous macules or papules with a central biting point could be found after initial severe itching occurred, Three cases showed signs of dermatosis with an allergic nature. The onset of dermatosis was between July 30 and Aug 12 and the durations varied from 5 days to over a month. The most frequent sites of stir lesions were the chest and abdomen (60.6%), and they were also observed on the neck (33.3%), arms (33.3%), shoulders (16.7%) and back (16.7%). Over 10 ants with their wings were collected in the work place and identified as Pachycondyla chinensis, subfamily Ponerinae. Conclusions : We thought that the outbreak of dermatosis was brought about by the ants flying into the work place through the open windows. Further studies on the factors contributing to the prosperity of the ants in this area are needed.

• Journal of Internet Computing and Services
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• v.16 no.6
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• pp.89-95
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• 2015

Traditional frequent pattern mining discovers valid patterns with no smaller frequency than a user-defined minimum threshold from databases. In this framework, an enormous number of patterns may be extracted by a too low threshold, which makes result analysis difficult, and a too high one may generate no valid pattern. Setting an appropriate threshold is not an easy task since it requires the prior knowledge for its domain. Therefore, a pattern mining approach that is not based on the domain knowledge became needed due to inability of the framework to predict and control mining results precisely according to the given threshold. Top-k frequent pattern mining was proposed to solve the problem, and it mines top-k important patterns without any threshold setting. Through this method, users can find patterns from ones with the highest frequency to ones with the k-th highest frequency regardless of databases. In this paper, we provide knowledge both on frequent and top-k pattern mining. Although top-k frequent pattern mining extracts top-k significant patterns without the setting, it cannot consider both item quantities in transactions and relative importance of items in databases, and this is why the method cannot meet requirements of many real-world applications. That is, patterns with low frequency can be meaningful, and vice versa, in the applications. High utility pattern mining was proposed to reflect the characteristics of non-binary databases and requires a minimum threshold. Recently, top-k high utility pattern mining has been developed, through which users can mine the desired number of high utility patterns without the prior knowledge. In this paper, we analyze two algorithms related to top-k high utility pattern mining in detail. We also conduct various experiments for the algorithms on real datasets and study improvement point and development direction of top-k high utility pattern mining through performance analysis with respect to the experimental results.

• Journal of Chest Surgery
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• v.38 no.8 s.253
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• pp.523-528
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• 2005

Background: Investigation of the change of ventricular function and mitral regurgitation after surgical repair of patient with anomalous origin of left coronary artery from the pulmonary artery (ALCAPA) is key issue for the better surgical outcome. Material and Method: From April 1986 to July 2002, 12 patients presented with ALCAPA. The median age at repair was 4 months. Surgical methods included left coronary artery transfer to the aorta (10), Takeuchi procedure (1), saphenous vein free graft bypass (1). Mitral valve was repaired in 1. Result: There were 2 hospital death $(16.7\%)$. The mean follow-up period was $7.1\pm4.1$ years (range, 7 months to 13 years). Four patients required postoperative circulatory assist for $2.2\pm1.1$ days and one needed left ventricular assist device (LVAD) for 1day. Postoperative echocardiography demonstrated significant improvements in mean fractional shortening $(33.4\pm9.1\%\;vs\;17.7\pm9.6\%,\;n=10,\;p<0.05);$ left ventricular end diastolic dimension $(33.4\pm7.3\;mm\;vs\;44.8\pm7.0\;mm,\;n=10,\;p<0.05)$ and systolic dimension $(22.2\pm7.5\;mm\;vs\;33.4\pm7.9\;mm,\;n=10,\;p<0.05)$. Severities of mitral regurgitation decreased in all survivors at 1st and 4th year follow-up echocardiography. There were 2 reoperation due to residual MR and right ventricular outflow obstruction (Takeuchi case). Conclusion: Anatomic repair of anomalous left coronary artery from the pulmonary artery offered an excellent surgical results, especially in terms of the recovery of left ventricle function and mitral regurgitation. However, preoperative indications for mitral procedure is to be evaluated.

• Korean Journal of Microbiology
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• v.37 no.3
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• pp.228-233
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• 2001

The acid tolerance response (ATR) of log-phase Salmouella enterica seroyar Typhimurium is induced by acid adaptation below pH4.5 and will protect cells against more severe acid. Two distinctive ATR systems in thisorganism are a log-phase and stationary-phase ATR in which acid adaptations trigger the synthesis of acid shockproteins (ASPs). We found that log-phase ATR system was strongly affected by environmental factor, low tem-perature, $25^{\circ}C$. Exposure to low temperature and mild acid has been shown to increase acid survival dra-matically, and this survival rate was showed higher than $37^{\circ}C$. Especially unadapted cells at $25^{\circ}C$ presented tenthousand folds survival increasing when compared with cells at $37^{\circ}C$. The degree of acid tolerance of rpoSwhich is blown to be required for acid tolerance more increase than $37^{\circ}C$. Even though AIR pattern of rpoSbetween unadapted and adapted was showed similar at pH 3.1, rpoS-dependent ATR system also has beendetected in low temperature because rpoSAp prevents sustained acid survival at $25^{\circ}C$. Therefore the resultssuggest low temperature ATR system requires rpoS-dependent and -independent both. To investigate the basisfor low temperature related ATR system, gene that was participated for low temperature acid tolerance (lat) wasscreened in virulent S. enterica serovar Typhimurium UKl Using the technique of P22- MudJ (Km, lacZ)-directed lacZ operon fusion, LF452 latA‥‥MudJ was isolated. The latA‥‥MudJ of S. enterica Typhimurium pre-vented low temperature acid tolerance response. Therefore latA is considered one of the important genes for acidadaptation.

• Journal of Chest Surgery
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• v.30 no.9
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• pp.862-868
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• 1997

Shone's syndrome is a congenital cardiac malformation that consists of multiple levels of left heart obstruction including supravalvular mitral ring, congenital mitral stenosis(parachute mitral valve), subaortic stenosis, and coarctation of aorta. This syndrome is a very rare congenital anomaly and its prognosis is poor. We experienced 9 patients with Shone's syndrome between 1985 and 1994. There were 8 male and 1 female patients, and mean age was 33.0$\pm$31.0 months ranged from 2 months to 1 1 years. The congenital mitral, stenosis and coarctation of aorta existed in all patients and the supravalvular mitral ring and subaortic stenosis in 4 patients. Two patients had all four anatomic lesions. 3 patients underwent one stage total correction and the other 6 patients underwent two staged operation that was initial coarctoplasty with thoracotomy and later correction of intracardiac anomalies with median sternotomy. A third operation was performed in 2 patients. These procedures included reoperation for coarctation and replacement of mitral valve for persistent mitral stenosis. There was no operative death at the first operation but two operative deaths at the second operation. The cause of death in two cases was severe heart failure secondary to left ventricular hypoplasia. There was no operative death at the third operation. The seven survivors have beeli followed from 11 months to 12 years(mean follow-up 6.7 $\pm$ 3.6 years). There was no late death and the New York HeArt Association activity level was class I for all patients. We conclude that a food lone-term outcome can be expected by proper surgical treatment tailred to each individual's anatomy and pathophysiology although the operative mortality and morbidity of Shone's syndrome are high.

• Asia pacific journal of information systems
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• v.17 no.4
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• pp.61-95
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• 2007

Small-and-medium sized enterprises(SMEs) represent quite a large proportion of the industry as a whole in terms of the number of enterprises or employees. However researches on information system so far have focused on large companies, probably because SMEs were not so active in introducing information systems as larger enterprises. SMEs are now increasingly bringing in information systems such as ERP(Enterprise Resource Planning Systems) and some of the companies already entered the stage of ongoing use. Accordingly, researches should deal with the use of information systems by SME s operating under different conditions from large companies. This study examined factors and mechanism inducing faithful appropriation of information systems, in particular integrative systems such as ERP, in view of individuals` active feedback-seeking behavior. There are three factors expected to affect end users` feedback-seeking behavior for faithful appropriation of information systems. They are management support, peer IT champ support, and IT staff support. The main focus of the study is on how these factors affect feedback-seeking behavior and whether the feedback-seeking behavior plays the role of mediator for realizing faithful appropriation of information systems by end users. To examine the research model and the hypotheses, this study employed an empirical method based on a field survey. The survey used measurements mostly employed and verified by previous researches, while some of the measurements had gone through minor modifications for the purpose of the study. The survey respondents are individual employees of SMEs that have been using ERP for one year or longer. To prevent common method bias, Task-Technology Fit items used as the control variable were made to be answered by different respondents. In total, 127 pairs of valid questionnaires were collected and used for the analysis. The PLS(Partial Least Squares) approach to structural equation modeling(PLS-Graph v.3.0) was used as our data analysis strategy because of its ability to model both formative and reflective latent constructs under small-and medium-size samples. The analysis shows Reliability, Construct Validity and Discriminant Validity are appropriate. The path analysis results are as follows; first, the more there is peer IT champ support, the more the end user is likely to show feedback-seeking behavior(path-coefficient=0.230, t=2.28, p<0.05). In other words, if colleagues proficient in information system use recognize the importance of their help, pass on what they have found to be an effective way of using the system or correct others' misuse, ordinary end users will be able to seek feedback on the faithfulness of their appropriation of information system without hesitation, because they know the convenience of getting help. Second, management support encourages ordinary end users to seek more feedback(path-coefficient=0.271, t=3.06, p<0.01) by affecting the end users' perceived value of feedback(path-coefficient=0.401, t=6.01, p<0.01). Management support is far more influential than other factors that when the management of an SME well understands the benefit of ERP, promotes its faithful appropriation and pays attention to employees' satisfaction with the system, employees will make deliberate efforts for faithful appropriation of the system. However, the third factor, IT staff support was found not to be conducive to feedback-seeking behavior from end users(path-coefficient=0.174, t=1.83). This is partly attributable to the fundamental reason that there is little support for end users from IT staff in SMEs. Even when IT staff provides support, end users may find it less important than that from coworkers more familiar with the end users' job. Meanwhile, the more end users seek feedback and attempt to find ways of faithful appropriation of information systems, the more likely the users will be able to deploy the system according to the purpose the system was originally meant for(path-coefficient=0.35, t=2.88, p<0.01). Finally, the mediation effect analysis confirmed the mediation effect of feedback-seeking behavior. By confirming the mediation effect of feedback-seeking behavior, this study draws attention to the importance of feedback-seeking behavior that has long been overlooked in research about information system use. This study also explores the factors that promote feedback-seeking behavior which in result could affect end user`s faithful appropriation of information systems. In addition, this study provides insight about which inducements or resources SMEs should offer to promote individual users' feedback-seeking behavior when formal and sufficient support from IT staff or an outside information system provider is hardly expected. As the study results show, under the business environment of SMEs, help from skilled colleagues and the management plays a critical role. Therefore, SMEs should seriously consider how to utilize skilled peer information system users, while the management should pay keen attention to end users and support them to make the most of information systems.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.224-229
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• 2003

Purpose : To examine various neonatal outcomes and perinatal factors resulting from assisted reproduction compared to that of spontaneous conception. Methods : This is a retrospective study. The control cases were all twins of spontaneous conception born between periods from January 1995 to June 2000. The study cases were identified from twins conceived by assisted reproduction in the same time peried. A total of 460 sets of twins consisted of 250 twins of spontaneous conception and 156 twins of assisted reproduction were studied. The primary outcomes were neonatal morbidity and mortality and the secondary outcomes were perinatal factors including number, length and cost of hospitalization for the delivery. Results : No differences were seen in various neonatal factors including gestational age, birth weight and incidences of respiratory distress syndrome, patent ductus arteriosus, necrotizing enterocolitis, hyperbilirubinemia, sepsis, intraventricular hemorrhage and the length of hospitalizations. Lower one minute and five minute Apgar scores and frequently encountered electrolyte abnormalities were observed in neonates of assisted reproduction. In general, the second twin of assisted reproduction had increased incidences of respiratory distress syndrome, sepsis and necrotizing enterocolitis than the first twin. Increased frequencies of preterm labor, hospitalization and elective cesarean section were seen among mothers who underwent artifical conception. However, overall hospital costs in terms of mothers hospitalization for the delivery and neonates hospitalization did not show differences. Conclusion : Assisted reproduction twins had similar neonatal morbidities, mortalities and perinatal morbidities compared to those born by spontaneous conception.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.525-531
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• 1999

Background: We analyzed five hundred patients who underwent either isolated or concomitant coronary artery bypass grafting(CABG) between November 1981 and June 1997. Material and Method: There were 330 males and 170 females with a mean age of 57.4$\pm$8.9 years. To evaluate the preoperative status, we performed electrocardiograghy, echocardiography, MIBI scan, Duplex sonogram, common blood test including CK and LDH and coronary angiography. Result: Preoperative clinical diagnoses were unstable angina in 282 (56.4%), stable angina in 141 (28.2%), postinfarction angina in 58 (11.6%), acute myocardial infarction in 8 (1.6%), variant angina in 7 (1.4%) and failed percutaneous transluminal coronary angioplasty in 4 (0.8%) patients. Preoperative angiographic diagnoses were three-vessel disease in 263 (52.6%), two-vessel disease in 93 (18.6%), one-vessel disease in 71 (14.2%), left main disease in 68 (13.6%), and others in 5 (1.0%) patients. Patients had various risk factors for coronary disease, and the frequency of the risk factors such as hypertension, diabetes and smoking showed increasing tendency year by year. We used saphenous vein grafts in 1143, internal thoracic artery grafts in 442, radial artery graft in 17, and gastroepiploic artery graft in 1 anastomosis. The mean number of grafts was 3.2$\pm$1.2 per patient. Concomitant operations were prosthetic valve replacement or valvuloplasty in 31, coronary endarterectomy and angioplasty in 27, left main coronary angioplasty in 13, carotid endarterectomy in 5, and neurologic problems, bleeding, and perioperative myocardial infarction. The mean follow-up period was 25$\pm$23 months and there were 5 cases of reoperation. Conclusion: We hope that the surgical results would improve with the accumulation of experience, application of new myocardial protection technique, and timely intervention of mechanical assisted devices.