• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.92-97
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• 2010

A study is conducted on thermal characteristics of biodiesel which is already being produced in many countries because of its stable supply of energy in non oil-producing countries and economical benefits against increasing oil price, and environment conservation. So biodiesel has been used as important energy source in the fuel fields and a mount of production has increased year by year. Therefore, it is very important to find out the thermal characteristics of biodiesel for ignition temperature, maximum pressure and thermal behavior. The purpose of this study is to compare on thermal characteristics of biodiesel, petroleum diesel and those mixtures. Also, the main study was performed by flash point testers and modified closed type of pressure vessel test (MCPVT). Based on the data of flash point and MCPVT, the ignition temperature and the maximum pressure of biodiesel was $182^{\circ}C$ and 40.1bar, and petroleum diesel was $54^{\circ}C$ and 29.8bar.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.131-137
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• 2021

The purpose of this study was to present the reference value of the intracranial translucency(IT) of the fetus using the mid sagittal plane of the post brain in the early pregnancy ultrasound screening test and to find the clinical significance. From August 2018 to February 2020, the IT of 1529 singleton fetus whose crown lump length were 40.6 mm to 78.3 mm in length among the mothers undergoing regular checkups at Hospital I were measured and analyzed retrospectively. As the crown lump length increased, the IT showed a 54.3% explanatory power and tended to increase(p<0.001). In addition, through frequency analysis, the standard value for the percentile of the IT by gestational weeks was calculated. As a result, it was possible to establish a standard value for Koreans with an IT, and it will be usefully applied as an auxiliary screening test for spina bifida in the evaluation of fetal post brain in early pregnancy.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.54-63
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• 2023

Pedestrian traffic needs to be accurately quantified to predict effectively pedestrian traffic accidents, however, pedestrian traffic is more difficult to measure than vehicle traffic. In this study, we suggest the time-and cost-effective application of mobile closed-circuit television (CCTV) using a smartphone as an alternative that can collect and analyze real-time data with little. In the present investigation, the pedestrian-vehicle conflict that can develop into an accident was defined as the pedestrian accident exposure. After installing mobile CCTV in 40 sections of Dongseong-ro, Daegu, the pedestrian accident exposure was estimated through negative binomial regression analysis using the collected data. The results of the analysis showed statistically significant changes in the pedestrian accident exposure variables. Based on the present results, a pedestrian accident exposure estimation model was developed which can be used in sections where pedestrian accidents may occur.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.1055-1064
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• 2023

This study attempts to understand the mediating effect of health self-efficacy in the relationship between health consciousness and health promoting behavior of nursing college students. The subjects of the study were 255 nursing college students attending nursing departments at four universities located in G city and J province. Collected data were analyzed by descriptive statistics, t-test, ANOVA, Pearson correlation, and multiple regression analysis using SPSS 25.0, and Sobel tests were conducted to verify the mediating effect. As a result, health self-efficacy showed a partial mediating effect between health consciousness and health promoting behavior(Z=5.54, p<.001). The higher the health consciousnes(β=.20, p<.001) and health self-efficacy(β=.39, p<.001), the higher the level of health promoting behavior. And the explanatory power(R2) explaining the health promoting behavior was 48%. Therefore, in order to improve the health promoting behavior of nursing college students, it is necessary to prepare an effective strategy to not only increase health consciousness but also strengthen health self-efficacy at the same time.

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.310-314
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• 2016

The search for natural antioxidants as alternatives to synthetic products is growing. Microalgae have emerged as a source of natural antioxidants with significant and diverse health-promoting properties. In this study, the effects of hot-water extraction conditions on total polyphenol compounds (TPC) production were investigated for lipid extracted microalgae (LEA). In order to enhance the polyphenol productivity, the extraction variables including solvents, temperature, time and ethanol concentration were optimized. The results showed hot-water extraction provided a higher extraction efficiency than the organic solvents and extraction at high temperatures showed a better extraction efficiency. While hot-water extract showed a higher extraction efficiency compared to 98% ethanol extraction, the mixture of water and ethanol (40:60 v/v) showed the highest production of polyphenols. The maximum polyphenols of 3.35 mg GAE (gallic acid equivalent)/g DM were obtained at the optimized extraction time of 10 min, $100^{\circ}C$ and 40% ethanol, respectively. Although Tetraselmis KCTC 12236BP was preprocessed by hexane to remove lipid for bio-diesel production, the results showed LEA contains relatively high level of polyphenols compared to untreated microalgae which can be used in the production of value-added materials. The predictions obtained from the developed Peleg's model were compared with the experimental data under the same operating conditions. The predicted and experimental data were consistent, indicating the reliability of the model.

• Korean Journal of Social Welfare
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• v.66 no.3
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• pp.209-230
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• 2014

The study is to show the prevalence of double-care burdened households who care simultaneously for children(under 6) and provide invalid elderly care for aging parents among women aged 30s to 40s in Korea. The study aims to place care as ordinary needs for our whole lifetime, not as a special happening to a certain age group at specific period. Also, study attempts to reveal that care experiences include both burden and pleasure, and that care relationship, such as care giver-receiver-assistants(second-helpers), strongly affects the diversity of caring experience. Results are as follows. 38.1% of the survey respondents report that they are/have ever been the double-care burdened households who carry both child care under 6 and elderly care suffering from health problems in the past or the present. If including those who expecting the double burden of care in the near future, the prevalence rate goes up to 54.9%. As hypothesized, caring includes both pleasure and burden. The order of pleasant feelings is child care> parents care>in-law parents care, and that of burden is in reverse. However, caring relationship has a strong influence on pleasure or agony of the caring experience. The association between the relationship and the experience, which is expressed by pleasure or pain, occurs to both daughter-parents and in-laws. Interestingly, the caring experiences by daughter to her parents tend to go more burdensome because their husbands do not commit their identity as carer aid, with no additional caring effort for their in-laws. In conclusion, some policy suggestions for double care problems are provided.

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.598-606
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• 2015

This study analyzed the characteristics of the disaster occurrence and disaster-prone zones on the 85 forest roads in the Jeollabuk-do area by referring to their forest environment factors. The on-site survey reveal the types of forest road disasters as follows: erosions of cutting slopes 54.1%, erosions of the filling slope 35.3%, collapses of cutting slopes with filling slope 9.4%, and erosions of road surface 1.1%. Disasters most frequently occurred in the vertical location (the hillside) and the horizontal location (the slope), and the forest factors affecting the road disasters were degree of cutting slopes in $31^{\circ}{\sim}40^{\circ}$, degree of filling slopes in $21^{\circ}{\sim}30^{\circ}$, and the soil texture of SiL. The most significant factors on the most frequent occurrence of forest road disasters were forest type of coniferous, slope aspect northeast, forest age of plantation and felling area, and rainfall in 1601~1700. An analysis of the occurrence of the forest road disasters in the Jeollabuk-do area showed a positive correlative relationship with the following factors of the forest environment within a 1% error: degree of cutting slope in $31^{\circ}{\sim}40^{\circ}$, annual accumulation rainfall in 1601~1700. and showed a positive correlative relationship with the following factors of the forest environment within a 5% error: horizontal location of valley, forest type of coniferous, length of slope more than 20 m, forest age of plantation and felling area, soil texture of SiL.

• Radiation Oncology Journal
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• v.3 no.2
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• pp.113-121
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• 1985

This is a retrospective analysis of 54 patients with stage I or II Non-Hodgkin's lymphoma involving the head and neck region treated with curative radiotherapy in the Department of Therapeutic Radiology, Seoul National University Hospital during the period of February 1979 through September 1982. The minimum follow-up period was 24 months. The review of histologic slides was available in 36 cases. Waldeyer's ring was the most common extranodal sites $(40\%)$. $41\%$ of patients were in the stage 1 and $59\%$ in the stage II by Ann Arbor classification. Of the 44 patients who responded after radiotherapy, 24 patients$(54.4\%)$subsequently relapsed. Regional recurrence rate was $29\%$, distant metastasis was $54\%$ and simultaneous regional recurrence and distant metastasis was $17\%$. The survival rate and disease free survival at 2 years were $57\%\;and\;45\%$ respectively. Those patients with a large primary lesion (over 6cm in diameter), multiple conglomerated, extranodal site and diffuse ceil type, experienced a high rate of distant metastasis. Therefore it seems desirable to study the use of adjuvant chemotherapy in those patients with a high probability of distant metastasis.

• Korean Journal of Bronchoesophagology
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• v.17 no.1
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• pp.5-8
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• 2011

The proliferation of new technologies has significantly enhanced the diagnostic capabilities of flexible bronchoscopy compared with traditional methods. Narrow band imaging (NBI), an optical technique in which filtered light enhances superficial neoplasms based on their neoangiogenic patterns, was developed to screen for central intraepithelial moderate or severe dysplasia, carcinoma in situ (CIS), and microinvasive neoplasia in patients at risk for lung cancer. Because angiogenesis occurs preferentially in dysplastic and neoplastic lesions, NBI may identify early dysplastic lesions better than white light bronchoscopy (WLB) currently in use. NBI bronchoscopy can be used not only to detect precancerous lesions, but also to screen for cancerous lesions. We prospectively evaluated 101 patients with suspected lung cancer between July 2009 and June 2010. All were previously scheduled for flexible bronchoscopy CT scans. Abnormal NBI was defined by Shibuya's descriptors (tortuous, dotted, or spiral and screw patterns). Biopsies of 132 lesions in 92 patients showed that 78 lesions (59.1%) were malignant and 54 (40.9%) were benign. The diagnostic sensitivity of bronchoscopy in detecting malignancy was 96.2% (75/78). When assorted by lesion pattern, the sensitivity and specificity of NBI bronchoscopy in detecting malignancies were 69.2% (54/78) and 96.3% (52/54), respectively, for the spiral and screw pattern and 14.1% (11/78) and 96.3% (52/54), respectively, for the dotted pattern. Unexpectedly, additional cancerous lesions were detected in five patients (2 dotted and 3 spiral and screw). As a screening tool for malignant lesions, NBI bronchoscopy should assess combinations of all three lesion. The dotted and spiral and screw patterns may be helpful in determining which lesions should be biopsied. NBI bronchoscopy may be useful not only for the diagnosis of early-stage lung cancer but also for more accurate local staging of lung cancer.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.54-54
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• 2010

Interplanetary space is filled with dust particles originating mainly from comets and asteroids. Such interplanetary dust particles lose their angular momentum by olar radiation pressure, causing the dust grains to slowly spiral inward Poynting-Robertson effect). As dust particles move into the Sun under the influence of Poynting-Robertson drag force, they may encounter regions of resonance just outside planetary orbits, and be trapped by their gravities, forming the density enhancements in the dust cloud (circumsolar resonance ring). The circumsolar resonance ring near the Earth orbit was detected in the zodiacal cloud through observations of infrared space telescopes. So far, there is no observational evidence other than Earth because of the detection difficulty from Earth bounded orbit. A Venus Climate Orbiter, AKATSUKI, will provide a unique opportunity to study the Venusian resonance ring. It equips a near-infrared camera for the observations of the zodiacal light during the cruising phase. Here we consider whether Venus gravity produces the circumsolar resonance ring around the orbit. We thus perform the dynamical simulation of micron-sized dust particles released outside the Earth orbit. We consider solar radiation pressure, solar gravity, and planetary perturbations. It is found that about 40 % of the dust particles passing through the Venus orbit are trapped by the gravity. Based on the simulation, we estimate the brightness of the Venusian resonance ring from AKATSUKI's locations.