• Journal of the Korean Magnetics Society
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• v.3 no.3
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• pp.201-207
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• 1993

Starting ingot of $Pr_{15}Fe_{77}B_{8}$ were prepared by vacuum induction melting under argon atmosphere. The ingot were induction melted in a quartz crucible and then ejected as a molten alloy throuth a 0.6 mrn orifice onto a rotating cop¬per wheel. An anisotropic magnet was prepared from ribbon by hot deformation techniques. A fully dense precursor magnet first made by pressing ribbons at $680^{\circ}C$ under a pressure of $21.8\;kg/mm^{2}$. A substantially oriented magnets were obtained by die-upset under various conditions. As the compression ratio increases, the $B_{r}$ value increases pronouncedly though $_{i}H_{c}$ decreases. Also, XRD analyses show increased diffraction peak from (006). From these results, it can be known that the magnetic easy axis was formed along the compression axis. As the die-upset speed increases, $_{i}H_{c}$ increases though $B_{r}$ decreases. The $B_{r}$ increases up to $750^{\circ}C$ of die-upset temperature and above this temperature decreases. The value of $4{\pi}M_{s}$ of the $Pr_{15}Fe_{77}B_{8}$ alloy prepared is found to be 11.8 KG. When the alloy was compressed by 0.8 under the die-upset speed of 0.05 m/sec at $750^{\circ}C$, $B_{r}$ was 11.0 KG indicating that the alloy has excellent magnetic anistropy. However, this alloy has some limitation because of low $_{i}H_{c}$.

• Journal of the Korean Geotechnical Society
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• v.33 no.3
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• pp.37-47
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• 2017

The geotechnical characteristics of frozen ground is one of the key design issues for the construction of infrastructure in cold region. In this study, the dynamic properties (shear modulus and damping ratio) of frozen and unfrozen soils sampled from Terra Nova Bay located in eastern Antarctica, where Jang Bogo station was built, were investigated using Stokoe-type resonant column test (RC). In order to freeze the reconstituted soil specimen, the RC testing equipment was modified by adding a cooling system. A series of resonant column tests were performed in frozen and unfrozen soils with various soil densities and temperatures. The shear modulus (G) and damping ratio (D) of soil frozen at $-7^{\circ}C$ were compared with those of unfrozen soil. In addition, the effect of temperature rise on the maximum shear modulus ($G_{max}$) and damping ratio was experimentally investigated. This study has significance in that the difference of dynamic soil properties between frozen and unfrozen soils and the effect of temperature rise on frozen soil were identified.

• Child Health Nursing Research
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• v.20 no.4
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• pp.275-282
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• 2014

Purpose: The purpose of this study was to identify effects of a maternal-child health education program for nurses in Tigray, Ethiopia. Methods: One-group pre-posttest design was used. The maternal-child health (MCH) education program was given to nurses from 5 health centers in Tigray, Ethiopia. Knowledge and confidence levels were measured before and after each education session. Data were analyzed using paired t-test. Results: The topics of the 5 educational sessions were family planning, antenatal care, care during labor, immunization, and integrated management of neonate, and child illness. Knowledge scores (1st: Z=3.931, p=.001; 2nd: Z=6.189, p <.001; 3rd: Z=5.658, p <.001, 4th: Z=8.734, p <.001, 5th: Z=14.167, p <.001) and confidence levels (1st: Z=8.467, p <.001; 2nd: Z=4.183, p <.001; 3rd: Z=4.992, p <.001) improved significantly. Conclusion: The findings of this study imply that the MCH education program for nurses was effective in developing the maternal-child health capacity of the nurses in Tigray, Ethiopia.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.621-630
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• 2006

Twelve beams made of lightweight high-strength concrete were tested to determine their diagonal cracking and ultimate shear capacities. A total of 12 beams without(4 beams) and with lightweight(8 beams) were tested in a stiff testing facility, and complete load-midspan deflection curves, including the maximum capacities portion, were obtained. The variables in the test program were concrete strength, which varied 35.4 MPa, 65.3 MPa; shear span-depth ratios a/d=1.5, 2.5, 3.5, 4.5; and tensile steel ratio between 0.57 and 2.3 percent. Also, we divided beam by diagonal tension crack and ultimate shearing strength to propose an equation. In addition, it analyzed comparison mutually applying existing proposal and guide. $V_{cr}$ was as result that AIK recommendations and Zsutty proposal decrease more than a/d=2.5, increased some in Mathey's proposal equation. $V_{cr,\exp}/V_{cr,cal}$ showed tendency of overestimation according to increase of tensile steel ratio and compressive strength of concrete. On the other hand, $V_{cr,\exp}/V_{cr,cal}$ is superior in conformability with an experiment result Zsutty's proposal among other equations. The proposal equation hew that expect $V_{cr}/V_u$, rationally about shearing strength. Therefore, shear strength an equation is considered to be utilized usefully evaluating capacity by change of the shear span depth ratio of lightweight concrete, tensile steel ratio, and compressive strength of the concrete in this research.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.473-476
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• 2008

Due to the pursuit of high function and international price increase in the field of construction, the application of the secondary product using cement is on the increase gradually in the construction industry in the pursuit of economic cost reduction by the shortening of the construction time like Expediting and the dry construction method at the same time. However, it is in very urgent situation of measures to improve the structural performance or durable performance because it is limited for use in terms of panel in interior exterior building or functional repair reinforce as yet. Accordingly, this study is to investigate applicability of permanent Formwork like mould with the structural performance or excellent durable performance in the field of construction, and to derive optimum mixture in the performance and quality of manufacture. As a result of analysis comparison with the dynamic and durable properties of vacuum extrusion molding high toughness cement panel according to the mixture of four conditions, this study has found that the test body of mixing ECC-DP3 using small filler and large granulated blast furnace slag and powder flame retardant had excellent relative hardness and bending stress strain. The durable performance has shown excellent tendency by the decrease of porosity and enhancement of water-tightness.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.3
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• pp.396-409
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• 2006

In this paper, first I try to sketch the changing Japanese labor market after 1990s, and then examine the so-called "Job $Caf{\acute{e}}$ program" in detail, which was initiated in 2004 by central and local governments to help young people fine suitable jobs, and finally investigate the possible direction for future labor policy as an important tool for revitalize the local economy. Latter half of 1990s witnessed the high unemployment rate among the population aged twenties in Japan, and the number of 'shinsotsu-mugyo', i.e. population not at work after completing high school or university, NEET (not in employment, education or training) and 'freeters' have grown rapidly. "Job $Caf{\acute{e}}$ program" was initiated as a public response to the increased youth unemployment, aiming at assisting young people's transition from education to career. In the Job $Caf{\acute{e}}$ program, job information service by MHLW, information service for high school students and university students by MEXT, placement service of career internship by METI are integrated into one service, and are provided by local government initiative, therefore named as "one stop service of employment". Although it is highly appreciated for one stop service, the Job cafe program has criticized for paying too much attention to the performance of projects, such as the number of users, and the number of successful job matching. At the final section of the paper, more practical spatial unit for executing effective regional plan on local employment and more empirical research on job search behavior are discussed.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.146-154
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• 2011

Korean contractors have been maintained sustainable growth since entering into overseas construction market for the first time in 1960' s. In 2010, Korean contractors ordered 761 billion (USD) from overseas markets. Especially, billion (USD) were earned by Korean contractors in overseas plant construction market which account for more than 80% of the total amount by Korean contractors. Nevertheless, many Korean contractors are suffering from lack of technological competitiveness and construction management skills in the design phase compared with global leading contractors. These conditions have directly effect on the success of projects in terms of cost, duration, and quality. So, this study focused on identifying the risk factors and developing risk priority method for the design phase of LNG plant projects whose market is expanding. Research procedures were conducted by the following three steps. First, total 57 risk factors were identified in design phase through extensive literature reviews and experts survey. Second, the authors developed risk priority method which are more suitable for design phase of LNG plant projects by using three criteria, Probability(P), Impact(I), and Coordination Index(CI). Finally, the suitability of risk priority method and practical applicability were verified through expert survey and interview. Consequently, if korean contractors use the suggested risk factors and priority method based on their own know-how and experiences, then more reasonable and rational risk management will be conducted in the design phase of LNG plant projects.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.72-80
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• 2010

The 1Gbps clock and data recovery (CDR) circuit using the proposed multi-point phase detector (PD) is presented. The proposed phase detector generates up/down signals comparing 3-point that is data transition point and clock rising/falling edge. The conventional PD uses the pulse width modulation (PWM) that controls the voltage controlled oscillator (VCO) using the width of a pulse period's multiple. However, the proposed PD uses the pulse number modulation (PNM) that regulates the VCO with the number of half clock cycle pulse. Therefore the proposed PD can controls VCO preciously and reduces the jitter. The CDR circuit is tested using 1Gbps $2^{31}-1$ pseudo random bit sequence (PRBS) input data. The designed CDR circuit shows that is capable of recovering clock and data at rates of 1Gbps. The recovered clock jitter is 7.36ps at 1GHz and the total power consumption is about 12mW. The proposed circuit is implemented using a 0.18um CMOS process under 1.8V supply.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.10 no.2
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• pp.173-178
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• 2007

Purpose: This study was conducted to analyze the clinical manifestation and natural course of benign transient hyperphosphatasemia (BTH) in children. Methods: A total of 17 children diagnosed with BTH between June 2006 and July 2007, were included in this study. Clinical records and laboratory tests were analyzed retrospectively for all children. Results: The mean age of the patients was $26.9{\pm}13.8$ months (range: 9 to 49 months). Nine of the 17 BTH cases (52.9%) occurred in patients that had previously suffered from infectious diseases. While the patients were suffering from BTH, the mean serum level of alkaline phosphatase (ALP) was $2,500.2{\pm}1,165.1$ U/L, however, these elevated serum ALP levels normalized within 7 weeks of recovery in all cases. In addition, a seasonal peak in the onset of BTH was observed from September to December. Further, the measurement of ALP isoenzymes in 7 of the patients with BTH, revealed a marked elevation of bone fraction. Conclusion: It is important for pediatricians to understand the clinical manifestation and benign course of BTH to avoid unnecessary diagnostic evaluation in children showing a transient increase in ALP activities.

• The Korean Journal of Malacology
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• v.28 no.4
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• pp.313-319
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• 2012

Mass production method on artificial seedling production of hard clam Meretrix petechialis was developed indoor culture system. Spawning of adult clam (SL $65.8{\pm}8.4mm$) was induced using the combined method of air exposure and water temperature raising. The fertilized eggs were developed to D-shaped larvae after 17.7 hours at $27^{\circ}C$ and hatching rate was 6.1%. Shell length (SL) of D-shaped larvae was measured to be $131.4{\pm}2.6{\mu}m$ and thereafter the larvae grew to the settled spats with SL $190.2{\pm}7.5{\mu}m$ in 4 days. Estimated survival rate of settled spats was 48.1%. Spat collection on 130,000 spats with SL $0.19{\pm}0.01mm$ performed conducted by sand bottom circulation filtering method. Collected spats grew up to $3.1{\pm}0.8mm$ in 46 days, $6.6{\pm}1.8mm$ in 87 days, and $10.5{\pm}0.9mm$ in 114 days. The relative growth between SL and shell height (SH) was calculated to be SH = 0.8501SL + 0.0196 ($R^2=0.9987$) during the whole spat period. During spats rearing, they were suffered from one time of mass mortality at SL 3.1 mm, but 51,000 spats were finally survived with the rate of 39.2% at 114 days of spat rearing in indoor tank system.