• Journal of Korea Foresty Energy
• /
• v.21 no.3
• /
• pp.1-9
• /
• 2002

Various types of acids, such as mineral acids, organic acids, and organic sulfonic acids, were used as catalysts in order to investigate their effectiveness during phenol liquefaction of pine bark. Hydrochloric arid was the most effective acid catalyst of the mineral acids used in this experiment for the phenol liquefaction, but the amount of the acid needed for more than 90% liquefaction was at least 11 mmol. Among the carboxylic acids used triflouroacetic acid (TFA) was effective for the liquefaction, but it was not possible to obtain liquefaction of more than 80%. Organic sulfonic acids, p-toluenesulfonic acid (PTSA) and methanesulfonic acid (MSA), showed remarkable effects for liquefaction, even in small amounts and at low liquefaction temperatures. Especially in the case of PTSA, a 92% liquefaction yield was obtained at the liquefaction condition of 14$0^{\circ}C$ for 2 h. Therefore, it was evident that the PTSA is a good acid catalyst for the phenol-pine bark liquefaction system.

• Spatial Information Research
• /
• v.19 no.2
• /
• pp.37-46
• /
• 2011

Recently in the field of GIS(Geographic Information System), data integration from various sources has become an important topic in order to use spatial data effectively. In general, the integration of spatial data is accomplished by navigating corresponding space object and combining the information interacting with each object. But it is very difficult to navigate an object which has correspondence with one in another dataset. Many matching methods have been studied for navigating spatial object. The purpose of this paper is development of method for searching correspondent spatial object considering local position error which is remained even after coordinate transform ation when two different building data sets integrated. To achieve this goal, we performed coordinate transformation and overlapped two data sets and generated blocks which have similar position error. We matched building objects within each block using similarity and ICP algorithm. Finally, we tested this method in the aspect of applicability.

• IMMUNE NETWORK
• /
• v.7 no.3
• /
• pp.117-123
• /
• 2007

Background: This study was designed to investigate the role of the hepatocyte growth factor (HGF) with regards to differentiation of somatic stem cells originating from the human umbilical cord blood (UCB) into hepatic lineage cells in vitro culture system. Methods: Mononuclear cells from UCB were cultured with and without HGF based on the fibroblast growth factor (FGF)-1, FGF-2, and stem cell factor. The cultured cells were confirmed by immunofluorescent staining analysis with albumin (ALB), cytokeratin-19 (CK-19), and proliferating cell nuclear antigen (PCNA) MoAb. ALB and CK-18 mRNA were also evaluated by reverse transcription-polymerase chain reaction. In order to observe changes in proliferating capacity with respect to the cultured period, CFSE with affinity to proliferating cells were tagged and later underwent flow cytometry. Results: In the HGF-treated group, cultured cells had a large oval shaped appearance with adherent, but easily detachable characteristics. In the HGF-non treated group, these cells were spindle-shaped with strong adherent characteristics. Expressions of ALB and CK-19 were evident in HGF-treated group compared to non-expression of those in to HGF-non treated group. Dual immunostaining analysis of the ALB producing cells showed presence of PCNA in their nuclei, and ALB and CK-18 mRNA were detected on the 21st day of cultured cells in the HGF-treated group. Conclusion: Our findings suggest that HGF has a pivotal role in differentiating somatic stem cells of human UCB into hepatic lineage cells in vitro.

• Korean Journal of Childcare and Education
• /
• v.12 no.4
• /
• pp.23-40
• /
• 2016

The purposes of this study were 1) to examine the differences in job stress, teacher efficacy, emotion-focused coping strategies and depression of teachers in early childhood education and care according to their demographic backgrounds, 2) to investigate the influences of these variables on depression. 586 teachers in ECEC answered the questionnaires and the collected data were analyzed through frequence, percentages, Pearson's correlations, One-Way ANOVA, Bonferroni post hoc test, and stepwise regression using SPSS 21.0. The findings are as follows. First, job stress was significantly different according to ECEC teachers' ages and types of centers they were employed at teacher efficacy was significantly different according to their ages and education levels, emotion-focused coping strategies and depression were respectively significantly different according to ages, types of centers and education levels. Second, ECEC teachers' depression was influenced by undercontrolled expressionof emotion-focused coping strategies, home connection and promotion of positive learning environment of teacher efficacy, undercontrolled thinkingof emotion-focused coping strategies and work overload and job stress in order. These results imply that a support system and a policy should be established for ECEC teachers to express and understand their emotions in a positive way and related information should be provided to them through workshops.

• Korean Journal of Community Nutrition
• /
• v.20 no.1
• /
• pp.30-40
• /
• 2015

Objectives: This study was performed to investigate the associations of food security with socio-demographic characteristics, nutrient intakes and mental health status among older Korean adults. Methods: This study was conducted using data from the 2008-2010 Korea National Health and Nutrition Examination Survey (KNHANES). Subjects were 4,451 adults aged 65~98 years. Food security was measured using a self-reported question on food sufficiency of subjects' household. Based on the answers, study subjects were classified into secure, mildly insecure, moderately insecure, and severely insecure groups. Dietary intake was estimated by 24-hour dietary recall. Nutrient intake was assessed by dietary reference intakes (DRI). As for mental health status, the data on mental stress, depression, and suicide ideation were used. Results: Rate of food insecurity in older adults was 14.3%. Old age, being female, low education, low income level, living alone, and discomfort in daily living were more related to food insecurity. Means of nutrient intakes were significantly different according to food security status. Intakes of calcium, potassium, and vitamin $B_2$ were lower than recommended intakes in all groups. Consumption amounts of soy and soybean products, vegetables, mushrooms, fruits, vegetable oils, meats, eggs, seafood, and dairy products were lower in food insecure groups. Mental stress, depression, and suicide ideation were higher in food insecure groups independent of the gender and income level. Conclusions: These present findings suggested that food security is related to mental health as well as nutrition status in older Korean adults. A national system that include food and psychosocial support programs for the elderly should be considered in order to improve the overall health of older Korean adults.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.21 no.3
• /
• pp.426-439
• /
• 2015

Purpose: The purpose of this study was to identify the core competencies of nursing students and to improve competency-based nursing education. Methods: A triangulation method was used. A literature review and focus group interviews (FGI) were used to identify nursing core competencies. The present level of nursing competencies of students was identified through the nursing core performance questionnaire. Results: 1) Nursing core competencies, including 23 different competencies, were categorized into seven areas through a literature review and qualitative research. These competencies included: desirable personality, attitude & interpersonal skills, professionalism, nursing knowledge & basic nursing skills, ability to cope with nursing situations, basic ability in nursing research, coping ability with changes in the healthcare environment, and leadership. 2) Core nursing skills, nursing research, and nursing leadership were the three lowest ranking competencies. Some courses in the curriculum were to be newly established in an e-learning system, student's portfolio in non-curriculum. Conclusions: Further research is needed in order to show effects of the changes. Changes after applying the strategy of a nursing education program will be measured. Continuous research in competency-based nursing education is needed.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.2
• /
• pp.49-58
• /
• 2020

In this study, we solve an online multi-object problem which finds object states (i.e. locations and sizes) while conserving their identifications in online-provided images and detections. We handle this problem based on a tracking-by-detection approach by linking (or associating) detections between frames. For more accurate online association, we propose novel online appearance learning with discrete fourier transform and partial least square analysis (PLS). We first transform each object image into a Fourier image in order to extract meaningful features on a frequency domain. We then learn PLS subspaces which can discriminate frequency features of different objects. In addition, we incorporate the proposed appearance learning into the recent confidence-based association method, and extensively compare our methods with the state-of-the-art methods on MOT benchmark challenge datasets.

• Macromolecular Research
• /
• v.8 no.4
• /
• pp.179-185
• /
• 2000

Generally vascular grafts with a relatively large inner diameter (> 5 mm) have been successfully employed for replacement in the human body. However, the use of small diameter grafts is limited, because these grafts rapidly occlude due to the thrombosis. The ideal blood-contacting surface of a prosthesis would be an endothelial cell (EC) lining, because the confluent monolayer of healthy ECs that culture natural blood vessels represents the ideal nonthrombogenic surface. For vascular graft application, the stable EC adhesion on surface under How conditions is very important. In this study, the adhesive strength of ECs attached on polymer surfaces coated with collagen type IV (Col IV), fibronectin (Fn), laminin (Ln), and treated with corona was investigated onto polyurethane (PU) films. The EC-attached PU surfaces were mounted on parallel-plate flow chambers in a How system prepared for cell adhesiveness test. Three different shear stresses (100, 150, and 200 dyne/㎠) were applied to the How chambers and each shear stress was maintained for 120 min to investigate the effect of shear stress and surface treatment condition on the EC adhesion strength. It was observed that the EC adhesion strength on the surface-modified PU films was in the order of Ln≡Fn > Col IV > corona 》 control. More than 70% of the adhered cells were remained on surface-modified PU surface after applying the shear stress,200 dyne/㎠ for 2 hrs, whereas the cells were completely detached on the control PU surface within 10 min after applying the same shear stress. It seems that the type of adsorbed proteins and hydrophilicitv onto the PU surfaces play very important roles for cell adhesion strength.

• Korea journal of population studies
• /
• v.5 no.1
• /
• pp.4-16
• /
• 1982

The Korean Population Control Program has been implementing under the jurisdiction of the Ministry of Health and Social Affairs through an existing network of health centers. This arrangement was successful in bringing population growth down to targeted level by the end of the Fourth Five Year Economic Planning, 1981. It is expected, however, that future goal will be harder to reach due to difficulty of reducing traditional family size norms further and to the projected increasing the number of eligible couples as the past Korean war baby boom generation enters the reproductive activity in the next few years. The recognition of the need for modification of population policy is increasing. The 1980 census shows that the total number of population reached approximately 38.5 million with 1.57 per cent of the growth rate. It was projected that the size of Korean Population will reach around 42 million and 51 million in 1986 and 2000 respectively. Furthermore, there is some argument as to whether decline in the birth rate in Korea is too slow to meet government target. Hence, a new development of population policy and greatly increased amount of effort will be needed in order to achieve Zero Population Growth Rate before the year 2050. The development of future national population policy and its related area are recommended as follow: 1. It is highly recommended that the population planning law governing both vital events of birth and death and population migration should be legislated. 2. The National Population Policy Council, Chaired by Deputy Prime Minister should be activated to implement and coordinate population program within ministries. 3. Responsible organization of population and family planning program should be established as a Bureau unit at central government level. 4. For the improvement of national vital registration, an existing system should be studied and developed.

• Elastomers and Composites
• /
• v.45 no.1
• /
• pp.2-6
• /
• 2010

The sizing treatments of PAN-based carbon fiber surfaces were carried out in order to improve the interfacial adhesion in the carbon fibers/nylon6 composite system. The parameter to characterize the wetting performance and surface free energy of the sized fibers were determined by a contact angle method. The mechanical interfacial properties of the composites were investigated using critical stress intensity factor ($K_{IC}$). The cross-section morphologies of sized CFs/nylon6composites were observed by SEM. As the experimental results, it was observed that silane-based sizing treated carbon fibers showed higher surface free energies than other sizing treatments. In particular, the KIC of the sizing-treated carbon fibers reinforced composites showed higher values than those of untreated carbon fibers-reinforced composites. This result indicated that the increase in the surface free energy of the fibers leads to the improvement of the mechanical interfacial properties of carbon fibers/nylon6 composites.