• 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 dental hygiene science
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• v.17 no.1
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• pp.38-45
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• 2017

We evaluated the association between sleep duration, dental caries, and periodontitis by using representative nationwide data. We examined 8,356 subjects aged ${\geq}19$ years who participated in the sixth Korea National Health and Nutrition Examination Survey (2013~2014). Sleep duration were grouped into ${\leq}5$, 6, 7, 8, and ${\geq}9$ hours. Presence of dental caries was defined as caries in ${\geq}1$ permanent tooth on dental examination. Periodontal status was assessed by using the community periodontal index (CPI), and a CPI code of ${\geq}3$ was defined as periodontitis. A chi-square test and multiple logistic regression analysis were used to determine statistical significance. Model 1 was adjusted for age and sex, model 2 for household income, educational level, and marital status plus model 1, and model 3 for smoking status, alcohol consumption, blood pressure level, fasting blood glucose level, total cholesterol level, and body mass index plus model 2. The prevalence of dental caries according to sleep duration showed a U-shaped curve of 33.4%, 29.4%, 28.4%, 29.4%, and 31.8% with ${\leq}5$, 6, 7, 8, and ${\geq}9$ hours of sleep, respectively. In the fully adjusted model 3, the risk of developing dental caries was significantly higher with ${\leq}5$ than with 7 hours of sleep (odds ratio, 1.23; 95% confidence interval, 1.06~1.43). The prevalence of periodontitis according to sleep duration showed a U-shaped curve of 34.4%, 28.6%, 28.1%, 31.3%, and 32.5%, respectively. The risk of periodontitis was significantly higher with ${\geq}9$ than with 7 hours of sleep in models 1 and 2, whereas the significant association disappeared in model 3. In a nationally representative sample, sleep duration was significantly associated with dental caries formation and weakly associated with periodontitis. Adequate sleep is required to prevent oral diseases such as dental caries and periodontitis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8836-8843
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• 2015

This study was performed to investigate the antiproliferative activities of supercritical extracts from phalsak(Citrus hassaku Hort ex Tanaka) and yeagam(Citrus iyo Hort. ex Tanaka) against human cervical carcinoma HeLa cells and the chemical compositions of the extracts. The anticancer properties of supercritical extracts were demonstrated using the MTT assay and Hoechst 33342 staining and the compositional analyses were conducted by using gas chromatography-mass spectrometry(GC-MS). The peel extracts of both species exhibited similar antiproliferative effect. The antiproliferative activity of the flesh extracts was not detected up to $400{\mu}g/mL$, whereas peel extracts of phalsak and yeagam reduced cell viability with 87.16% and 92.95% at $400{\mu}g/mL$, respectively. There was a dramatic increase of the apoptotic body formation in the cell treated with peel extracts while no apoptotic body formation detected in the cell treated with flesh extracts at 100, $200{\mu}g/mL$. By GC-MS analysis, 27 and 31 kinds of compounds identified in flesh and peel of phalsak, while 27 and 29 kinds of compounds were identified in flesh and peel of yeagam, respectively. 1,1,4,4-Tetramethyl-2-tetralone(20.86%), alloimperatorin(8.15%), limonene(11.23%), and auraptene(7.29%) were major in peel of phalsak, whereas limonene(22.19%), linalool(11.23%), and ${\gamma}$-sitosterol(9.12%) were major in peel of yeagam.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.35-47
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• 2001

Traffic represents one of the largest sources of primary air pollutants in urban area. As a consequence. numerous abatement strategies are being pursued to decrease the ambient concentration of pollutants. A characteristic of most of the these strategies is a requirement for accurate data on both the quantity and spatial distribution of emissions to air in the form of an atmospheric emission inventory database. In the case of traffic pollution, such an inventory must be compiled using activity statistics and emission factors for vehicle types. The majority of inventories are compiled using passive data from either surveys or transportation models and by their very nature tend to be out-of-date by the time they are compiled. The study of current trends are towards integrating urban traffic control systems and assessments of the environmental effects of motor vehicles. In this study, a methodology of motor vehicle emission calculation by using real-time traffic data was studied. A methodology for estimating emissions of CO at a test area in Seoul. Traffic data, which are required on a street-by-street basis, is obtained from induction loops of traffic control system. It was calculated speed-related mass of CO emission from traffic tail pipe of data from traffic system, and parameters are considered, volume, composition, average velocity, link length. And, the result was compared with that of a method of emission calculation by VKT(Vehicle Kilometer Travelled) of vehicles of category.

• Journal of Korean Academy of Nursing
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• v.1 no.1
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• pp.64-76
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• 1970

This report will present a clinical and statistical analysis of 210 case of Ectopic pregnancies who were treated at the Department of Obstetrics and Gynecology at Chung Nam Medical Center from January, 1966 to March, 1970. The results obtained are as follows; 1. The total number of Ectopic pregnancies was 8.22%. 2. The occurrence of Ectopic pregnancy was high in June(13.81%), low in October(2.98%). There was a higher occurrence of Ectopic pregnancy in the summer than in the winter. 3. The average age of all patients was 33.25 years. The most frequent age for this type of pregnancy was 31-35 years (32.86%) . The youngest patient was 18 years old and the oldest was 50. 4. Multipara occurred in 82.38% of the cases; Mulipara in 17. 62% and the occurrence of primipara was especially high, 20.95%. 5. 48.09% of the women had previously experienced normal deliveries; 42.8% had received artificial abortions and 5.23% had experienced spontaneous abortions. 3.8% had a previous history of Ectopic pregnancy. It was found that the occurrence of Ectopic pregnancy was more frequent in those women who had a D & C in the Past. 6. The average length of infertility was 21.7 months. The shortest length was 60 days; longest period of infertility was 19 years. 7. The occurrence of Ectopic pregnancy is higher (29.27%) in patient who have experienced only one previous D & C. The total number of patients who received a D & C was 58.57%. 3. Ectopic symptoms appeared during the first 4.7 weeks (mean) and most frequently occurred between the 5th and 6th weeks (48.57%) of pregnancy. The Symptoms were: -99.04% complained of lower abdominal pains. -80.95% experienced abnormal uttering bleeding. -42.38% experienced bleeding before the occurrence of pain. -18.57% experienced pain before the occurrence of bleeding. -8.57% experienced both pain and bleeding. -7.62% experienced only bleeding. -22.86% experienced only pain. 9. In-77.62% of the cases the annexal mass palpated. 91.42% complained of abdominal tenderness. 42.38% complained of pain when the cervix was examined. 10. Culdocentesis was performed in 86.19% of the cases. In 92.82% of the cases the presence of an Ectopic pregnancy was accurately diagnosed 11. 71.90% of the Ectopic pregnancies occurred in the ampule portion of the ovarian tube, of the total number of gestations, 40.95% were tubal abortions and 59.05% were ruptured. The ruptured group occurred more frequently in the islamic portion and interstitial portion of the tube than the aborted group. The aborted group occurred more frequently in the fimbrial extremities of the tube. 12. The blood pressure (systolic) was noted at 119-80mmHg in 81.89% of the total cases. Hemoglobin value was noted at over 8gm/㎗ in 58.57% of the cases. The average blood transfusion was 2.3 pints. 13. In 52.86% of the Ectopic pregnancies the right side of the ovarian tube was affected. The left side of the tube was affected in 47.14% of the cases. 14. 3.33% of the patients were not given an accurate diagnosis. 15. The kinds of operation performed were as follows; Salpingectomy, 41.43%; Adnectomy, 38.57% and Adnectomy with total hysterectomy, 19.05%. 16. The patient mortality rate was significantly small; only 1 case out of 210 died. This patient most likely had a profuse hemorrhage because of a ruptured tube before her admission to the hospital. 17. The patients personal feelings and attitudes must be treated with care. Particularly patients who are concerned about vaginal bleeding or the impossibility of another pregnancy.

• Journal of the Korean earth science society
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• v.27 no.4
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• pp.464-474
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• 2006

The paleoceanography since 14 ka was reconstructed based on the planktic foraminiferal assemblages of core sediments from the outer shelf of the Korea Strait. Planktic foraminifera in the core sediments can be divided into four assemblages: A, B, C, and D. Assemblage A consists mainly of Globigerinoides ruber group and Globigerinoides conglobatus with low abundance (less than 10%), indicating the tropical-subtropical water mass. Assemblage B is composed of Pulleniatina obliquiloculata and Neogloboquadrina dutertrei, the indicator of Kuroshio Current, and shows the aspect of the inflow of the Tsushima Current into the Korea Strait. Assemblage C yields polar-subpolar species, mainly Neogloboquadrina incompta and N. pachyderma. It decreases upward of the core. Assemblage D contains coastal water species such as Globigerina bulloides and G. quinqueloba. It is abundant in the lower to middle region of the core. From the analysis of distributions of each assemblage and the result of age datings in the core, it is suggested that the Korea Strait played a role of channelling the East China Sea and the East Sea after the LGM (ca. 14 ka). During this time, the coastal water, affected by fresh waters originated from the river systems of China and/ or the Korean Peninsula, flourished around the Korea Strait and theses coastal water might entered to the East Sea. Around 8.5 ka, the effect of the Tsushima Current started to strengthen in this region, and the present current system seems to be formed at about $7{\sim}6ka$.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.41-53
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• 1997

Geochemical data of soil and water samples were presented in order to assess the environmental impart for drinking water sites. Microscopic observation of rock samples and physical and chemical analysis of soil and water samples were undertaken. The geology of study areas are classified into three groups such as granitic rocks, meta-sedimentary rocks and sedimentary rocks. Enrichment of heavy metals derived from those rocks is not found in this study areas. Soils were analyzed for Cu, Pb, Zn, Cd and Cr using AAS extracted by HNO$_3$+HClO$_4$ and 0.1 N HCl. Heavy metal concentrations in soils are within the range of those in uncontaminated soils. In comparison of metal contents extracted by 0.1 N HCl and HNO$_3$+HC1O$_4$, less than 10% of the heavy metals are present in the exchangeable fraction. In particular, an pollution index has been proposed to assess the degree of soil contamination. Pollution index in soils are between 0.03 and 0.47 therefore, soils are not polluted with heavy metals. Deep groundwaters within granitic rocks have been evolved into Na$\^$＋/-HCO$_3$$\^$-/ type, whereas other deep groundwaters evolved into Ca$\^$2＋/-HCO$_3$$\^$-/ type. The predominance of Na$\^$＋/ over Ca$\^$2＋/ in deep groundwaters within granitic rocks is a result of dissolution of plagioclase, but for sedimentary and meta-sedimentary rocks, dissolution of calcite is a dominant factor for their hydrogeochemistry. The pH, conductivity and contents of the most dissolved ions in the water increase with depth. Shallow groundwaters, however, are highly susceptible to pollution owing to agricultural activities, considering the fact that high contents of nitrate, chloride and potassium, and high K/Na ratio are observed in some shallow groundwaters. In a thermodynamic approach, most natural water samples are plotted within the stability fields of kaolinite and smectite. Therefore, microcline and other feldspars will alter to form clay minerals, such as kaolinite and smectite. From the modelling for water-rock interactions based on mass balance equation, models accord well with behavior of the ions and results of thermodynamic studies are derived.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.177-183
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• 2008

Ac/Ds mutant lines of this study were transgenic rice plants, each of which harbored the maize transposable element Ds together with a GUS coding sequence under the control of a promoterless(Ds-GUS). We selected the mutants that were GUS expressed lines, because the GUS positive lines will be useful for identifying gene function in rice. One of these mutants was identified knock-out at Oszinc626(NP_001049991) gene, encoding a RING-H2 zinc-finger protein, by Ds insertion. In this mutant, while primary root development is normal, secondary root development from lateral root was very poor and seed development was incomplete compare with normal plant. RING zinc-finger proteins play important roles in the regulation of development in a variety of organisms. In the plant kingdom, a few genes encoding RING zinc-finger proteins have been documented with visible effects on plant growth and development. The consensus of the RING-H2(C3-H2-C3 type) domain for this group of protein is $Cys-X_2-Cys-X_{28}-Cys-X-His-X_2-His-X_2-Cys-X_{14}-Cys-X_2-Cys$. Oszinc626 encodes a predicted protein product of 445 amino acids residues with a molecular mass of 49 kDa, with a RING-zinc-finger motif located at the extreme end of the C-terminus. RT-PCR analysis indicated that the expression of Oszinc626 gene was induced by IAA, cold, dehydration, high-salinity and abscisic acid, but not by 2,4-D, and the transcription of Oszinc626 gene accumulated primarily in rice immature seeds, root meristem and shoots. The gene accumulation patterns were corresponded with GUS expression.

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.391-400
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• 2005

Special Practitioner exists based on the need for special fields that are required to manage difficult patients with specialized skills distinguished from General practitioner. The purpose of dental specialist system is to manage patients who are not treatable by general practitioner by training doctors specializing in one specific field, thereby, enhancing health of the public. Oral Medicine deals with orofacial pain, oral soft tissue disease, forensic dentistry, oral diagnosis. In these days, living environments of city life bring about increase in stress which ultimately lead to increase in prevalence of temporomandibular disorder, oral soft tissue disease, neuropathies such as trigeminal neuralgia, and hence, the number of patients seeking help of those symptoms tend to increase. The purpose of this study was to analyze the rate of referrals and the routes of patients seeking help by investigating 3,707 patients who visited Department of Oral Medicine, College of Dentistry, Yonsei University, from August, 2004 to April, 2005. The results were as follows: 1. The types of disease referred to the Department of Oral Medicine were orofacial pain, oral soft tissue disease, forensic dentistry, oral diagnosis. 2. The rate of referrals was 58.51% which implies that more than half of the patients visiting the Department of Oral Medicine were referred. 3. The types of institution which made referrals were analyzed, and as a result, dental clinics made most of the referrals with the rate of 83.23%, while that from medical or oriental medical institutions was 16.78%. 4. Among the patients who visited the Department of Oral Medicine on their own, 30.52% gained the information about the Department of Oral Medicine from internet and mass media, and from neighbors. From the above results, most of the patients visiting the Department of Oral Medicine were found to be referred not only from the field of dentistry but also from the field of medicine. These suggest that Oral Medicine manages patients who are not treatable by general dental practitioners, and medical specialists tend to cooperate with the Department of Oral Medicine to manage diseases associated with Oral Medicine. Therefore, the role of Oral Medicine can be considered to be important as a special field, and the results of this study should be considered when working out a policy of Dental specialist system on demand and supply of residents in the future.

• Radiation Oncology Journal
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• v.9 no.1
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• pp.47-52
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• 1991

From April,1983 through April,1989, we have treated histologically proven 21 patients with oligodendroglioma using 6 MV linear accelerator at the Division of Radiation Therapy, Kangnam 51. Mary's Hospital Catholic University Medical College. These are 8% of the irradiated 246 primary brain tumors during the same period. To investigate influencing factors on the survival of irradiated U patients with oligodendroglioma, we analyzed the cerebral location of the involvements, initial symptoms, CT findings and survival rates, retrospectively. One case was lost to follow up and excluded from survival data. Of the 28 patients, thirteen were male and 8 female. Ages ranged from 5 to 68 years with a median age of 38 years. Radiation doses varied from 3900 cGy to 0480 cGy and were given for 5 to 8 weeks. All but one were supratentorial. The involvement of the frontal and parietal lobes were 10 (48%) patients in each and temporal lobe in 8 (38.1%). Histological diagnosis was made by stereotactic biopsy in 3 and postoperatively in 18. The type of surgery was divided into partial, subtotal and total resection in 7,9 and 2 cases respectively. In 6 cases, chemotherapy was also tried during or after radiation therapy. Major presenting symptoms were headache, cerebral motor, nausea & vomiting and epilepsy in 18,12, 7 and 5 respectively in decreasing order. In CT analysis, low density (02%), cystic mass (33%), calcifiestion (66%) and positive contrast enhancement (42.8%) were observed as the highest frequency. Mean survival duration after radiation therapy was 38 months (K-M methods). We could not achieve statistically significant factors influencing on the survival rate after radiation therapy for oligodendrogliomas by one or two tail test.