• Current Optics and Photonics
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• v.3 no.6
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• pp.583-589
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• 2019

We report experimental results on 940-nm 350-mW AlGaAs/InGaAs transverse single-mode laser diodes (LDs) adopting graded-index separate confinement heterostructures (GRIN-SCH) and p,n-clad asymmetric structures, with improved temperature and small-divergence beam characteristics under high-output-power operation, for a three-dimensional (3D) motion-recognition sensor. The GRIN-SCH design provides good carrier confinement and prevents current leakage by adding a grading layer between cladding and waveguide layers. The asymmetric design, which differs in refractive-index distribution of p-n cladding layers, reduces the divergence angle at high-power operation and widens the transverse mode distribution to decrease the power density around emission facets. At an optical power of 350 mW under continuous-wave (CW) operation, Gaussian narrow far-field patterns (FFP) are measured with the full width at half maximum vertical divergence angle to be 18 degrees. A threshold current (I_th) of 65 mA, slope efficiency (SE) of 0.98 mW/mA, and operating current (I_op) of 400 mA are obtained at room temperature. Also, we could achieve catastrophic optical damage (COD) of 850 mW and long-term reliability of 60℃ with a TO-56 package.

• Journal of Elementary Mathematics Education in Korea
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• v.5 no.1
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• pp.55-75
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• 2001

The purpose of this paper is to find out the full extent of abilities of elementary students on area of operations and the effects on student's affective domain toward mathematics, after providing 3rd grade students with Skemp's play activities instead of providing activities suggested in the textbook of 7th curriculum. For this study, we will first analyse new elementary mathematics curriculum of 3rd grade and then explore mathematical factors for play activities related to operational sections. The play activities are revised from that of Skemp's for our classroom circumstances, but the ideas included from Skemp's such as thinking aloud were not changed. The experimental group while consists of 39 students were taught Skemp's play activities instead of usual textbook activities for 30 hours for the second term. In all other area, both the experimental group and the comparative group were taught the same contents. Statistical data is as follows 1) In addition and subtraction, the experimental group had 5.6% higher score than the comparative's, but the difference of mean of the both groups is not significant within 5% level. 2) In multiplication and division, the experimental group had 7.8% higher score than the comparative's and also the difference of mean of the beth within 5% level is significant. 3) When measured the effects in affective domain, the interests, attitude, and values for mathematics had about 10% higher score after the experiment than before the experiment. So we conclude that Skemp's activities are more effective than the activities suggested in the textbook on the area of operations, especially in multiplication and division.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.131-136
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• 2004

Osseointegration involves anchoring dental implants to stable bone rather than to soft-tissue. Clinical osseointegration is currently defined as the process whereby alloplastic material is asymptomatically and rigidly fixed and maintained in bone during functional loading. Full osseointegration is necessary for the success of long-term dental implants. Recent developments in computer assisted measurement of bone formation have improved maxillofacial examination and osseointegration. Computer assisted examination has also proved effective in dental implantology. This investigation was aimed to determine osseointegration in immediate and delayed implantation in the dog mandible using dental computed tomography (CT) and bone scintigraphy. Five adult (mean age of 2 years) mongrel dogs with a mean weight of 9.1 kg were used in this investigation. Titanium alloy implant systems with 4 mm in diameter and 10 mm in length were chosen for insertion. The second and third left mandibular premolars in each dog were extracted for the delayed implant insertion. Twelve weeks later, the second and third right mandibular premolars were extracted for the immediate implant insertion. Before the delayed and immediate implantation procedures and 0, 4, 8, and 12 weeks after the insertions, dental CT and scintigraphy were conducted. The CT and scintigraphic images indicate that reconstruction of bone surrounding of the immediate implant can be as successful as reconstruction of bone surrounding of the delayed implant.

• Journal of Chest Surgery
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• v.33 no.6
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• pp.502-506
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• 2000

Background: Anticoagulant therapy can be required during pregnancy with prosthetic heart valves. Warfarin and heparin provide real protection against thromboembolic phenomena, but they also carry serious risks for the fetus and the mother. In an attempt to identify the best treatment for pregnant women with cardiac valve prostheses who are receiving anticoagulant, we studied 19 pregnancies, the warfarin was discontinued and heparin was administered every 12 hours by subcutaneous injection in doses adjusted to keep the midinterval aPTT in the therapeutic range(at least 2-2.5 control) from the conception to the 12th week of gestation and oral antiocagulant was then administered until the middle of the third trimester in the therapeutic range(at least 2 INR), and heparin therapy was restared until delivery. Also in order to avoid an anticoagulant effect during delivery, it has been our practice to instruct women to either discontinue their heparin injections with the onset of labur or to stop heparin injections 12 hours prior to the elective induction of labour. Result: The outcome of 19 pregnancies managed with above protocol was spontaneous abortion in 3 cases, voluntary termination in 2 cases, premature delivery at 35 weeks in 1 case and delivery at full-term in 14 cases. There was no maternal morbidity and moratality and fetopathy. Conclusion: We conclude that in the second and third trimester of pregnancy, warfarin provide effective protection against thromboembolism, Oral antiocagulant therapy should be avoided in 2 weeks before delivery because of the risk of serious perinatal bleeding caused by the trauma of delivery to the anticoagulated fetus. However, the substitution of heparin at first trimester and 2 weeks before delivery reduce the incidence of complications.

• Journal of Korean Public Health Nursing
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• v.16 no.2
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• pp.315-324
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• 2002

Objectives : This study was conducted to explore the relating factors with the delivery of low-birth-weight infants in Pyungtaek city. Methods : A questionnaire survey was obtained from 51 mothers with low-birth-weight babies and 90 mothers with full-term normal babies from April to October in 2001. Questionnaire consisted of demographic characteristics, dietary habits including alcohol. drugging, and smoking, past and present disease, prenatal risk factors and prenatal check-up, and complications related to labor and delivery. Results : 1. In the low-birth-weight infants group, father's education level and mother's height were significantly lower, and proportion of old age mothers was significantly higher than those of the normal infant group. 2. Mothers with low-birth-weight infants experienced more premature rupture of membrane, placenta previa, ecclampsia, and twin pregnancy than mothers with normal infants. Gestational period of mothers with low-birth-weight infants was significantly shorter than that of mothers with normal infants. 3. No differences were found in eating habit, alcohol and drug ingestion, smoking, exposing to dangerous materials in two groups, but both groups were highly exposed to indirect smoking, although mothers rarely smoke. Conclusion : The findings of this study indicate that high risk group such as less educated, or older mothers need more prenatal health assessment and support from public health services. Addition to determine the risk factors related to the delivery of low-birth-weight infants, public health nurses pay more attention and develop efficient management system for vulnerable women and infants.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.3-23
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• 1997

The growth in fast-track construction and repair has prompted major efforts to develop high-early-strength concrete mix compositions. Such mixtures rely on the use of relatively high cement contents and accelerator dosages to increase the rate of strength development. The measures, however, seem to compromise the long-term performance of concrete in applications such as full-depth patches as evidenced by occasional premature deterioration of such patches. The hypothesis successfully validated in this research was that traditional methods of increasing the early-age strength of concrete, involving the use of high cement and accelerator contents, increase the moisture and thermal movements of concrete. Restraint of such movements in actual field conditions, by external or internal restraining factors, generates tensile stresses which introduced microcracks and thus increase the permeability of concrete. This increase in permeability accelerates various processes of concrete deterioration, including freeze-thaw attack. Fiver reinforcement of concrete is an effective approach to the control of microcrack and crack development under tensile stresses. Fibers, however, have not been known of accelerating the process of strength gain in concrete. The recently developed specialty cellulose fibers, however, were found in this research to be highly effective in increasing the early-age strength of concrete. This provides a unique opportunity to increase the rate of strength gain in concrete without increasing moisture an thermal movements, which actually controlling the processes of microcracking and racking in concrete. Laboratory test results confirmed the desirable resistance of specialty cellulose fiber reinforced High-early-strength concrete to restrained shrinkage microcracking an cracking, and to different processes of deterioration under weathering effects.

• Journal of Yeungnam Medical Science
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• v.30 no.1
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• pp.21-24
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• 2013

Hemolytic disease in a newborn that causes early jaundice is common. It is often due to the Rh (D) and ABO incompatibility, but rarely due to unexpected antibodies. Among these unexpected antibodies, the anti-$Di^a$Dia antibody rarely occurs. The anti-$Di^a$ antibody was observed in the serum and red-cell eluate of an infant, and in the serum of his mother. The frequency of the appearance of the $Di^a$ antigen in the Korean population is estimated to be 6.4-14.5%. This paper reports a case of hemolytic disease in a newborn associated with the anti-$Di^a$ antibody. A full-term male infant was transferred to the authors' hospital due to hyperbilirubinemia the day after his birth. The laboratory data indicated a hemoglobin value of 11.6 g/dL, a reticulocyte count of 10.6%, a total bilirubin count of 14.4 mg/dL, a direct bilirubin count of 0.6 mg/dL, and a positive result in the direct Coombs' test. Due to the identification of an irregular antibody from the maternal serum, an anti-$Di^a$ antibody was detected, which was also found in the eluate made from the infant's blood. The infant had been treated with phototherapy and intravenous immunoglobulin since the second day after his birth and was discharged due to an improved condition without exchange transfusion. Therefore, in cases of iso-immune hemolytic disease in a newborn within 24 hours from birth who had a negative result in an antibody screening test, the conduct of an anti-$Di^a$ antibody identification test is recommended due to the suspicion of an anti-$Di^a$ antigen, followed by early administration of intravenous immunoglobulin.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.7
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• pp.1675-1683
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• 1995

A numerical study of the fluid flow and heat transfer characteristics of the two-dimensional impingement jet with a confinement plate has been carried out. The fluid flow was calculated by solving the full Navier-Stokes equation. In doing that, the well known SIMPLER algorithm was used and the trouble making convection term was discretized according to QUICKER scheme. The energy equation was simply solved by using the SOR method. For the Reynolds number of 10000, two channel heights, say 1.5 and 3.0 times the jet exit width, and two thermal boundary conditions constant wall temperature and constant wall heat flux were considered. Discrete heat sources were flush mounted along the impingement plate at a distance of 0, 2, 3, 4, 5, 6, 10, 12, times the jet exit width from the stagnation point. The length of each heat source is 4 times the jet exit width long. The Nusselt number averaged over each heat source was compared with experiment. Comparison shows that both calculations and experiment have the secondary peak of Nusselt number at downstream of stagnation point, even though there is a little quantitative difference in between. The difference is believed due to abscure thermal boundary condition in experiment and also accuracy of turbulence model used. The secondary peak is shown to be caused by rigorous turbulent flow motion generated as the wall jet flow is retarded and developes into the channel flow without flow reversal.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.146-152
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• 2004

Ghrelin is an acylated peptide recently identified as the endogenous ligand for the growth hormone (GH) secretagogues receptor 1a (GHS-R1a) and is involved in a novel system for regulating GH release. To understand the long-term effects of ghrelin, here we constructed six myogenic expression vectors containing the cDNA of swine mature ghrelin (pGEM-wt-sGhln, pGEM-wt-hGhln), ghrelin mutant of $Ser^3$ with $Trp^3$ (pGEM-mt-sGhln, pGEM-mt-hGhln) and truncated ghrelin derivative (pGEM-tmtsGhln, pGEM-tmt-hGhln) encompassing the first 7 residues of ghrelin (including $Ser^3$ substituted with $Trp^3$) and adding a basic amino acid, Lys (K) in the C-terminus. The constructs, pGEM-wt-sGhln, pGEM-mt-sGhln and pGEM-tmt-sGhln were linked with the ghrelin leader sequence, while the pGEM-wt-hGhln, pGEM-mt-hGhln and pGEM-tmt-hGhln were linked with a leader sequence from the human growth hormone releasing hormone (hGHRH). Intramuscular injection of 200 ${\mu}g$ pGEM-wt-sGhln or pGEM-tmt-sGhln augmented growth over 3 weeks in normal rats and peaked at day 21 or 14 post-injection respectively, whose body weight gains were on average approximately 6% or 19% heavier over controls. However, other injectable vectors had no such enhanced growth effects. Our results suggested that the efficacy of the ghrelin leader sequence was more effective than that of hGHRH in our system. Moreover, the results indicated that skeletal muscle might have the ability to posttranslationally modify the in vivo expressed ghrelin. And the most strikingly, the short ghrelin analog seems to mimic the biological effects more efficiently when compared with the full-length ghrelin.

• Clinical and Experimental Pediatrics
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• v.45 no.11
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• pp.1422-1425
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• 2002

Subcutaneous fat necrosis in neonates is a rare disease characterized by skin lesions, which may be single or multiple, poorly circumscribed and often tender erythematous nodules or plaques on cheeks, buttocks, back, arms, and thighs. These symptoms are usually self-limited; resolution occurs over a period of weeks to months. Subcutaneous fat necrosis affects full term and healthy-appearing infants who have experienced perinatal distress such as hypoxic insult, birth trauma and hypothermia. Most skin lesions appear within the first two weeks of life. We experienced a case of subcutaneous fat necrosis in a neonate with hypoxic insult and report the case with a brief review of the literature.