• Clinical and Experimental Reproductive Medicine
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• v.32 no.3
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• pp.223-230
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• 2005

Objective: This study was performed to evaluate the accuracy of hysterosalpingography (HSG) for evaluating female infertility patients by comparison with hysteroscopic and laparoscopic examination. Methods and Material: Total 219 infertile patients were retrospectively analyzed between January 1, 2002 and December 31, 2003. Ninety seven patients (44.3%) were primary infertility, 122 patients (55.7%) were secondary infertility. We performed hysteroscopic and laparoscopic examination on next cycle when HSG revealed any abnormal finding, and 3~6 cycles later if HSG was normal. Results: The accuracy of HSG was 65.2% compared with hysteroscopic examination (sensitivity 88.4%, specificity 46.4%, false positive rate 53.6%, false negative rate 11.6%). The most common abnormal finding of hysteroscopy was uterine synechia (67.4%) followed by endometrial polyp, uterine anomaly (e.g. uterine septum), endometrial hyperplasia. Compared with laparoscopic examination, the accuracy of HSG was 76.9% (sensitivity 98.9%, specificity 70.6%, +LR 3.36, -LR 0.02). The positive predictive value of normal patent tube was excellent (99.6%) but that of proximal tubal blockage was only 46.7%. The unilateral tubal obstruction of HSG was poor accuracy (+LR 3.85 -LR 0.68) and 70% of those was patent by laparoscopic examination. Laparoscopic examination also revealed that 53% of patients had peritubal adhesion and 37% of patients has additional pelvic findings, especially endometriosis. Among the patients had normal HSG, 53.5% patients with normal ultrasonography was diagnosed endometriosis (25.6% of them had endometriosis stage I-II). Conclusion: Normal HSG shows a high negative predictive value. Nevertheless, the incidence of associated pelvic disease in the normal HSG group is high enough to warrant diagnostic laparoscopy if nonsurgical treatment is unsuccessful. Because HSG has poor accuracy in predicting distal tubal blockage and peritubal adhesion, and poor positive predictive value of proximal tubal blockage, laparoscopic examination could be considered in abnormal HSG group.

• Research in Community and Public Health Nursing
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• v.31 no.spc
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• pp.525-533
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• 2020

Purpose: Workers in special employment relationship (WSERs) are workers in nonstandard employment arrangements who lack worker protection accorded in standard employment arrangements. This study aimed to describe self-rated health (SRH) and depressive symptoms (DS) among Korean WSERs in comparison to regular wage workers (RWW) and identify associations between working conditions and those outcomes. Methods: In this study, secondary data analysis using the 5th Korean Working Conditions Survey was used. The sample totaled 29,120, including 1,538 WSERs and 27,564 RWWs. Sociodemographic and work-related characteristics were employed as explanatory variables and SRH and DS as dependent variables. Using multiple logistic regression, the determinants of fair/poor SRH and DS were identified. Results: The prevalence rates for fair/poor SRH and DS in WSERs were 25.2% and 28.3%, respectively, and 20.7% and 25.0% in RWWs, respectively. Compared to RWWs, WSERs had 31% (aOR=1.31, 95% CI=1.14~1.49) and 20% (aOR=1.20, 95% CI=1.06~1.36) higher odds of SRH and DS, respectively. Some factors, such as a lack of rest guarantee and sickness presenteeism, had a larger influence in the WSER than in the RWW group. Conclusion: Compared to RWWs, WSERs reported having poorer working conditions and were more likely to report poor general and mental health. Therefore, in Korea, public health policymakers should consider measures to protect the working conditions and health of WSERs, a growing segment of the working population. The study produced new epidemiological evidence regarding the relationships between employment arrangements and health.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.2
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• pp.291-299
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• 2013

The purpose of this study was to examine effects of socio-demographic, health, and delinquent behavior factors on internet addiction among the Korean youth. This study used the 2009 Korean Youth Health Risk Behavior On-line Survey data. It selected 73,238 cases of junior and senior high school students from the raw data and conducted a secondary data analysis. Frequency analysis, chi-square test and logistic regression analysis was conducted. Being male, living without parents, low economic status, poor academic record, poor subjective health status, poor subjective well-being, high level of stress, presence of depression and experience of drug use significantly increased likelihood of internet addiction. Findings may be used for developing strategies to deal with internet addiction among adolescents in Korea.

• Korean Journal of Materials Research
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• v.23 no.1
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• pp.7-12
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• 2013

The $Cu_2ZnSnS_4$ (CZTS) thin film solar cell is a candidate next generation thin film solar cell. For the application of an absorption layer in solar cells, CZTS thin films were deposited by pulsed laser deposition (PLD) at substrate temperature of $300^{\circ}C$ without post annealing process. Deposition time was carefully adjusted as the main experimental variable. Regardless of deposition time, single phase CZTS thin films are obtained with no existence of secondary phases. Irregularly-shaped grains are densely formed on the surface of CZTS thin films. With increasing deposition time, the grain size increases and the thickness of the CZTS thin films increases from 0.16 to $1{\mu}m$. The variation of the surface morphology and thickness of the CZTS thin films depends on the deposition time. The stoichiometry of all CZTS thin films shows a Cu-rich and S-poor state. Sn content gradually increases as deposition time increases. Secondary ion mass spectrometry was carried out to evaluate the elemental depth distribution in CZTS thin films. The optimal deposition time to grow CZTS thin films is 150 min. In this study, we show the effect of deposition time on the structural properties of CZTS thin film deposited on soda lime glass (SLG) substrate using PLD. We present a comprehensive evaluation of CZTS thin films.

• Journal of Welding and Joining
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• v.32 no.4
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• pp.26-33
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• 2014

The metallurgical and mechanical characteristics, toughness and corrosion resistance of dissimilar welds between super duplex stainless steel UNS S32750 and carbon steel ASTM A516Gr.70 have been evaluated. Three heat inputs of 21.12, 24.00, 26.88kJ/cm were employed to make joints of dissimilar metals with flux cored arc welding(FCAW). Based on microstructural examination, vermicular ferrite was formed in the first layer of weld at low heat input(21.12kJ/cm) and $Cr_{eq}/Ni_{eq}$ of 1.61 while acicular ferrite was formed in last layer of weld at high heat input(26.88kJ/cm) and $Cr_{eq}/Ni_{eq}$ of 1.72. Ferrite percentage in dissimilar welds was lowest in the first layer of weld regardless of heat inputs and it gradually increased in the second and third layers of weld. Heat affected zone showed higher hardness than the weld metal although reheated zone showed lower hardness than weld metal due to the formation of secondary austenite. Tensile strengths of dissimilar welds increased with heat input and there was 100MPa difference. The corrosion test by ferric chloride solution showed that carbon steel had poor corrosion resistance and pitting corrosion occurred in the first layer(root pass) of weld due to the presence of reheated zone where secondary austenite was formed. The salt spray test of carbon steel showed that the surface only corroded but the amount of weight loss was extremely low.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.2
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• pp.259-268
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• 2018

The $PM_{2.5}$ samples were collected for every 6th day during one year at a suburban site in the Namwonsi, Jeollanamdo, Republic of Korea. Samples were analyzed for elemental carbon (EC), organic carbon (OC), and water-soluble organic carbon (WSOC), and levoglucosan. Although the water-soluble fraction of fine particulate OC consistently showed over a year, levoglucosan fraction of WSOC varied considerably from month to month. In this study, non-biomass-burning WSOC ($WSOC_{NBB}$) and biomass-burning $WSOC_{BB}$ were calculated with measurements of organic source tracer, levoglucosan, to better understand the temporal distribution and sources of WSOC. Two methods of predicting the secondary organic carbon from the biomass-burning $WSOC_{BB}$ Method and the EC-tracer Method were compared. Poor correlations between SOC estimated between two methods suggested that the use of the EC tracer method to estimate SOC may be significantly flawed. Direct measurements of levoglucosan and WSOC can provide a reasonable estimate of secondary organic carbon concentrations.

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.398-407
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• 2021

This study intended to identify causes of poor tree vigor in the Hanbando coastal forest by investigating its geographical environment, climate condition, soil physicochemical characteristics, and growth condition of Pinus thunbergii. It divided the forest into an area with poor tree vigor or dead standing trees and a control area with good tree vigor and examined them separately. The survey showed that stand density was significantly higher in the area with poor tree vigor. In contrast, the crown width in the area with good tree vigor was wider. The number of dead standing trees and the stand density showed a negative correlation. The stand density and diameter at breast height (DBH), tree height, crown height, and crown width also showed a negative correlation. The result indicated that, as the tree's stand density increases, the crowns of individual trees overlapped and the lower branches died. Then crown height and crown width decreased, and the number of leaves and photosynthesis was reduced, leading to lower tree height and weaker growth of breast diameter. As a result, tree vigor weakened, and combined with environmental pressures from the lack of moisture and nutrients in coastal soil and salty wind, P. thunbergii in coastal areas is expected to die massively. Although the causes of dead standing trees and poor tree vigor of P. thunbergii in the Hanbando coastal forest are complicated, poor management of adequate tree density in response to the growth of P. thunbergii is the primary cause. The secondary cause is external environmental pressures, including unfavorable soil conditions and salty and strong wind that obstruct the growth of P. thunbergii.

• Journal of Yeungnam Medical Science
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• v.13 no.2
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• pp.211-224
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• 1996

The patients of developmental dislocation of the hip(DDH) are almost found after walking age because of early diagnosis of DDH in younger children is not easy. A controversy still exists as to the relative value of closed and operative management in the treatment of a child who has reached walking age. This study is a report of the results of 16 patients(17 cases) in developmental dislocation of the hip who have visited our hospital at the age of 9 months to 3 years old, and have been followed more than 12 months (12-112 months) on review of plain radiographs and arthrograms. The results were as follows : 1. The age at diagnosis was 16.4 months(9-31 months) in average. The methods of treatment were conservative for 8 cases, and operation for 4 cases and secondary operation for 5 cases who were failed with conservative therapy. 2. By Severin's radiologic grade, the result was good in 4 cases, fair in 3 cases and poor in 1 case in conservative treatment. In operative treatment, fair was in 2 cases and poor in 2 cases. In secondary operative patients who were failed with conservative therapy, good was in 2 cases, fair in 2 cases and poor in 1 case. 3. Avascular necrosis of femoral head was developed in 3 cases. 4. In the good reduction as determined by arthrogram according to Race and Herring, we can get a favorable result in conservative treatment, and in the poor reduction as determined by arthrogram, the better result in operative treatment can be expected.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.241-249
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• 2022

The current research attempts to measure the level of the acceptance of the Blackboard System (BBS) during the Corona crisis, and whether this is one of the reasons for the low use of the BBS at Al-Jouf University. To achieve this, the technology accepting model in the time of crisis (TAMTC) has been proposed to measure the degree of acceptance by students, which was then applied to a random sample of 339 of such. The results show a high level of student acceptance, despite their lower use of the system. The research also highlights the importance of upgrading e-courses and that the discontinuation of exam disqualification of students is secondary to their poor course attendance.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.185-187
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• 2004

In many multiple output SMPS, the cross regulation between the output voltage is so poor that the linear regulator is usually added to avoid this problem. Therefore, manufacturing cost is increased. In this paper, the TTFC(Two Transistor Forward Converter) using the magamp was presented to obtain better cross regulation between the multiple output SMPS. Also, as the synchronous rectifier was applied in the secondary section, whole efficiency can be improved. In this paper, the mode analyses in steady slate and experimental results of the prototype to verify the validity of the presented converter are presented and discussed.