• Journal of Korean Society of Steel Construction
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• v.19 no.6
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• pp.737-749
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• 2007

Flexural design of double composite box girder over the interior pier for three-span continuous bridge was performed by the LRFD method. The maximum span length of the continuous bridge ranged from 80m to 120m and the relative ratio of the span length was assumed to be 1:1.25:1. The girder section was designed for the strength limit state and service limit state with additional design check for constructibility. Before the bottom concrete and compression flange showed a complete composite action, the buckling of lower compression flange was checked. The flexural stiffness and flexural resistance characteristics for the section and for the constituent members such as tension flange, compression flange, and web were analyzed for different thicknesses of the bottom concrete on top of the compression flange. The effect of the distribution ratio of steel between the top and bottom flanges was investigated by analyzing ductility behavior and stress distribution through the girder's depth for several different relative area ratios of steel between the top and bottom flanges. It was found that a total amount of 15% of steel can be saved by applying the double composite system compared with that of the conventional composite system.

• Journal of the Korean Institute of Gas
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• v.13 no.2
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• pp.41-48
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• 2009

I collected the cases of CNG vehicle accidents which had happened for 30 years and analyzed the causes of the accidents according to each type of cylinders. There are about six accidents including three cylinder explosion accidents due to bad heat treatment, one composite damage, one CNG vehicle fire, and one fuel piping accident owing to the poor maintenance. When looking into the cylinder types involved in the accidents and the causes, 29% of the cylinder accidents are Type I and 24% Type IV, 16% Type II, and 14% Type III. 37% of the accidents are caused by the defects of the raw materials and the errors of a manufacturing process, 16% by the stress corrosion cracking as a result of the repetitive use, 15% by the cylinder's explosion on account of the malfunction of PRD(Pressure Relief Device) and the overpressure. The remainders of the causes are fire and unknown causes. Therefore, cylinder manufacturers have to strengthen quality management of raw materials and manufacturing process and painting regardless of each type of cylinder. Also bus operators need to make an effort to keep safety condition through every day check.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.225-233
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• 2008

The purpose of this study is to investigate the relationship between leisure motives of private guards and their sports participation, verify the casual relationship between its variables, and finally present the need of leisure activities for them and related politic data. The subjects are the private guards who work for a private guard company in Seoul in 2007, Except the data having inadequate answers among the 200 copies which are collected by stratified cluster random sampling, the data of total 193. The result of reliability analysis check up was here below; Chronbach's ${\alpha}= .835$. SPSSWIN 15.0 program is used for the reliability and correlation analysis of the questionnaire. The followings are the conclusions from this investigation through above methods and procedures. First, leisure motives affect the experience of sports participation; the more relaxational motives are, the less the experience of sports participation is. Second, leisure motives affect the degree of sports participation; the more motives of recognizing competence are, the more the frequency of sports participation is; the more intellectual motives are, the longer the period of sports participation is; the more relaxational motives are, the less the intensity of sports participation is, while the more motives of recognizing competence are, the more the intensity of sports participation is.

• Journal of Animal Science and Technology
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• v.45 no.2
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• pp.163-168
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• 2003

This study was carried out to estimate the effects of environmental factors on the activities and rectal temperatures(heat tolerance) of Holstein dairy cows in a summer season. An activity-meter(Alpro system$^{\circledR}$) was used to record activities of 77 cows for 24 hours. The feeding standards for milking and dry cow were formulated with concentrates and corn silages based on the NRC(1998). Cows to check temperature were kept in stanchions and temperature was checked in rectum. Ambient temperature was $29.0^{\circ}C$ between 1 p.m. and 3 p.m. of the day. The rectal temperatures were affected by parities and status of milking or dry(p<0.01). The activities recorded between 9 a.m. and 12 a.m., and between 1 p.m. and 4 p.m. were not effected by the status of lactating and dry. The rectal temperature of lactating cow was 39.0${\pm}0.03^{\circ}C$, it was higher than dry cow(38.6${\pm}0.04^{\circ}C$). A higher activity of cow under third parity at 1 p.m. to 4 p.m. was observed comparing with fourth and above. The activities were tended to decrease with an increase of parity. Rectal temperature was negatively correlated with milk compositions, which were fat, protein, solid-not-fat and total solid except lactose.

• Women's Health Nursing
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• v.17 no.3
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• pp.225-242
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• 2011

Purpose: The purpose of this study was to identify students' experiences of performance and their satisfaction with clinical nursing practice in Women's health nursing. Methods: Data was collected using questionnaire consisting of 104; 89,; and 82 nursing activities with 12; 10; and 7 domains for delivery floor, obstetric, and gynecologic wards retrospectively. Five hundred ninety nursing students from 10 four year and one three year colleges, were recruited and selected for data collection. Results: Site specific core nursing activities among top 15 items of performed experience were: interpreting fetal monitoring; massage for pain reduction; breathing technique; perineal pad change; non stress test; manual check for uterine contraction; and position change for the delivery floor. Experiences of clinical nursing practice for the obstetric ward and the gynecologic ward were identified and ranked as well. Observation of delivery, measurement & test during labor and observation of anesthesia and operation were the highest ranked activity domains of satisfaction for delivery floor, obstetric and gynecologic wards retrospectively. Conclusion: Discussions are needed to standardize curriculum for clinical practice in women's health nursing initiated at the level of Korean Society of Womens' Health Nursing by reflecting this result. Strategic approaches are emphasized in order to enhance a collaboration between clinical fields and colleges.

• Journal of agricultural medicine and community health
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• v.42 no.4
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• pp.226-233
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• 2017

Objective: The purpose of this study was to describe and understand self-care status of the aged diabetic patients with noncompliance after hospital discharge. Methods: A qualitative research method was used for the study design. The participants were 15 diabetic patients aged 65 or older who had been admitted more than two times for hyperglycemia in the past 1 year in a general hospital in Daegu. Data were collected from November 1 2015 to March 1 2016 through in-depth personal interview. Results: Patients' knowledge level on causes and symptoms of diabetes was low. Most participants rarely and irregularly checked blood sugar at home. They were under a lot of stress from their family. Due to old age and illness they did not have sufficient physical activity and they have had rarely regular meals. They considered the self-care education program unnecessary and there was limitations of accessibility for education. Conclusions: The aged diabetic patients who had the repeat admission did not perform self-care activities properly and had problems especially in blood glucose check, support from their family, and health education after returning home. More personalized and community-based self-management education programs will be necessary.

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.53-63
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• 2013

Bored pre-cast piles using PHC piles is widely used in foundation of building structures constructed in urban areas because noise and vibration due to pile installation are low. However, since slime is formed at the base of borehole and the density of bearing stratum surrounding the base of borehole is decreased due to stress relaxation in drilling process of bored pre-cast pile method, the base load capacity of bored pre-cast piles is very low compared to the strength of bearing stratum. In this study, a new type of PHC pile, which short steel pipe with the same diameter as the PHC pile is attached to the pile tip, is developed to increase the base load capacity of bored pre-cast piles. In order to check the effect of the use of new PHC pile on the base load capacity of bored pre-cast piles, field pile load tests are performed for bored pre-cast piles using the new and existing PHC piles. Results of the pile load tests show that the new PHC pile gives higher base load capacity to bored pre-cast piles than the existing PHC pile, since the tip of new PHC pile is penetrated to undisturbed bearing stratum passing through the slime at the base of borehole and the loosened bearing stratum under the slime by pile driving using light hammer.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.453-460
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• 2004

To prevent penetration of rainwater into the landfill site is the main purpose of the final cover in landfill sites. Conventional designs of landfill covers uses geotextiles such as geomembrane and GCL, and clay liners to lower the permeability of final covers of landfill sites. However, differential settlement and the variation of temperature in landfill sites cause the development of cracks or structural damage inside the final cover and it is also difficult to obtain clay - the main material of the compacted clay liner in Korea. Thus the former final cover system that suggests geomembrane and GCL or compacted clay liner has several limitations. Therefore, an alternative method is necessary and one of them is the application of SRSL(self-Recovering Sustainable Liner) material. SRSL is two different layers consist of individual materials that react with each other and form precipitates, and with this process lowers the permeability of the landfill final cover. SRSL generally is made up of two layers, so that when a internal crack occurs the reactants of the two layers migrate towards the crack and heal it by forming another liner. In this study the applicability of SRSL material for landfill final cover was examined by performing; (1) jar test to verify the formation of precipitate in the mixture of each reactants, (2) falling head test considering the field stress in order to confirm the decrease of permeability or prove that the hydraulic condctivity is lower than the regulations, (3) compression tests to judge weather if the strength satisfies the restricts for landfills, (4) freeze/thaw test to check the applicability of SRSL for domestic climate. In addition, the application of waste materials in the environmental and economical aspect was inspected, and finally the possibility of secondary contamination due to the waste materials was examined by performing elution tests.

• Journal of Plant Biotechnology
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• v.35 no.1
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• pp.55-61
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• 2008

Previous studies on genetic transformation of chrysanthemum using cold regulated gene (BN115) have been conducted and the PCR and Real-Time PCR based method to determine the presence of the transferred cold regulated gene in the chrysanthemum was established. To check whether over-expression of BN115 gene in transgenic chrysanthemum will enhance their tolerance to cold stress, the transgenic chrysanthemum were grown under low temperature condition and several cold signalling including growth characteristics, stoma size and shape, SPAD value and ion leakage test were investigated. The transgenic chrysanthemum in the low temperature growth chamber grow much faster in term of the height, number and size of the leaves than those of wild-type plants and damage of transgenic plant caused by the low temperature was much less than that of wild-type plants. The stoma type and size of transgenic plant leaves grown at $5^{\circ}C$ were much similar to of wild-type plant cultured on $25^{\circ}C$ It has been found that SPAD value of transgenic plants was much higher than those of wild-type, but the EC density being lower under low temperature condition.

• The Journal of Engineering Geology
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• v.30 no.1
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• pp.17-30
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• 2020

An optical televiewer is a geophysical logging device that produces continuous high-resolution full-azimuth images of a borehole wall using a light-emitting-diode and a complementary metal-oxide semiconductor image sensor to provide valuable information on subsurface discontinuities. Recently, borehole imaging logging has been applied in many fields, including ground subsidence monitoring, rock mass integrity evaluation, stress-induced fracture detection, and glacial annual-layer measurements in polar regions. Widely used commercial borehole imaging logging systems typically have limitations depending on equipment specifications, meaning that it is necessary to clearly verify the scope of applications while maintaining appropriate quality control for various borehole conditions. However, it is difficult to directly check the accuracy, implementation, and reliability for outcomes, as images derived from an optical televiewer constitute in situ data. In this study, we designed and constructed a modular fractured borehole model having similar conditions to a borehole environment to report unprecedented results regarding reliable data acquisition and processing. We investigate sonde magnetometer accuracy, color realization, and fracture resolution, and suggest data processing methods to obtain accurate aperture measurements. The experiment involving the fractured borehole model should enhance not only measurement quality but also interpretations of high-resolution and reliable optical imaging logs.