• Journal of the Korean Society for Precision Engineering
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• v.27 no.3
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• pp.89-94
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• 2010

The pretensioner is used to retract the belt webbing and tighten up any slack in the event of a crash. The retracting force of the pretensioner helps move the passenger into the optimum crash position in his or her seat. In this paper, the new concept of an operating mechanism of the pretensioning system is presented. The internal gear design program is developed using MATLAB. Two kinds of numerical analysis model are created. The first one, the rigid body dynamic model, is used to estimate the performance of several gear pairs. The initial performance of the new operating mechanism is analyzed and the best combination of the gear pairs is selected. The second one, the structural dynamic model, is used to calculate the deformation of the gear teeth. To decrease the deformation and interference of the teeth, the shape of the gear pairs is changed.

• Child Health Nursing Research
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• v.17 no.2
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• pp.69-73
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• 2011

Purpose: This study was designed to identify mother and infant related factors that influence child-care stress among the mother of newborn infants. Methods: Data were collected through self-administered questionnaires and descriptive statistics, correlation and multiple regression were used to analyze the data. The data survey was conducted with 957 conveniently selected mothers of infants when they visited a public health center in Seoul to have their children immunized. Results: The average item score for the Childcare Stress Inventory was 38.03, for the Edinburgh Postnatal Depression Scale, 9.31 and for the Degree of Bother Inventory, 23.42. The CSI was positively correlated to EPDS (r=.44, p<.001) and DBI (r=.40, p<.001). Also these two variables explained 30.0% of CSI in infants' mothers. Conclusion: These findings are expected to expand the understanding about postpartum mothers' child-care stress and can contribute to the development of comprehensive interventions based on community health nursing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.684-688
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• 2011

The feeding habits of Paralichthys olivaceus in the Uljin marine ranching area, located on the mid-eastern coast of Korea, were studied from January to November 2009. In total, 381 specimens were collected; fish ranged in size from 15.4 to 59.0 cm in total length. P. olivaceus is a carnivore, mainly consuming other fishes and crustaceans. The prey items of P. olivaceus changed ontogenetically. Small individuals fed on decapod crustaceans while large ones fed heavily on other fishes. The diet of P. olivaceus varied seasonally. Fish comprised the main prey items throughout the year. The stomach contents index (SCI) of each size class increased and the dietary breadth index (DBI) of each size class decreased as individuals grew.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.1
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• pp.7-13
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• 2013

3D stacked IC is one of the promising candidates which can keep Moore's law valid for next decades. IC can be stacked through various bonding technologies and they were reviewed in this report, for example, wafer direct bonding and atomic diffusion bonding, etc. As an effort to reduce the high temperature and pressure which were required for high bonding strength in conventional Cu-Cu thermo-compression bonding, surface activated bonding, solid liquid inter-diffusion and direct bonding interface technologies are actively being developed.

• Journal of ILASS-Korea
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• v.28 no.1
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• pp.32-42
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• 2023

In this study, spray characteristics of n-heptane and propane were investigated under different injection pressure using various imaging techniques such as Mie-scattering, DBI (diffuse back-illumination), and Schlieren imaging techniques. NI compact RIO system was used to control a test injector. Spray penetration length, length-to-width ratio and number of black pixels were calculated by using MATLAB software to compare spray characteristics of each fuel. Longer spray penetration length and higher length-to-width ratio were observed in propane spray because of flash boiling caused by high saturated vapor pressure. Spray collapse occurred in propane spray due to the high plume-to-plume interaction. Moreover, rapid evaporation occurred in propane spray, so that nozzle tip wetting could not be observed. Rapid evaporation of propane also caused fewer residual droplets compared to n-heptane spray. Therefore, propane is advantageous in reducing the generation of soot emission from large droplets that are not atomized. However, additional evaluation should be conducted considering combustion efficiency and the possibility of deposits by nozzle tip icing during fuel injection.

• Tunnel and Underground Space
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• v.15 no.1 s.54
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• pp.47-54
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• 2005

One of the standard procedures of discontinuity survey is the joint set identification from the population of field orientation data. Discontinuity set identification is fundamental to rock engineering tasks such as rock mass classification, discrete element analysis, key block analysis. and discrete fracture network modeling. Conventionally, manual method using contour plot had been widely used for this task, but this method has some short-comings such as yielding subjective identification results, manual operations, and so on. In this study, the method of discontinuity set identification using genetic algorithm was introduced, but slightly modified to handle the orientation data. Finally, based on the genetic algorithm, we developed a FORTRAN program, Genetic Algorithm based Clustering(GAC) and applied it to two different discontinuity data sets. Genetic Algorithm based Clustering(GAC) was proved to be a fast and efficient method for the discontinuity set identification task. In addition, fitness function based on variance showed more efficient performance in finding the optimal number of clusters when compared with Davis - Bouldin index.

• Journal of the Korean Society for information Management
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• v.32 no.1
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• pp.153-169
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• 2015

The combined approach of using ego-centric network analysis and dynamic citation network analysis for refining the result of LDA-based topic modeling was suggested and examined in this study. Tow datasets were constructed by collecting Web of Science bibliographic records of White LED and topic modeling was performed by setting a different number of topics on each dataset. The multi-assigned top keywords of each topic were re-assigned to one specific topic by applying an ego-centric network analysis algorithm. It was found that the topical cohesion of the result of topic modeling with the number of topic corresponding to the lowest value of perplexity to the dataset extracted by SPLC network analysis was the strongest with the best values of internal clustering evaluation indices. Furthermore, it demonstrates the possibility of developing the suggested approach as a method of multi-faceted research trend detection.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.121-130
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• 1997

The aim of this study is to forcast the economic impact of Yosu-Kwangyang harbour on the regional employment. Industries in relation to this harbor can be divided into three parts; related industries to harbor(RI), direct dependent industries on harbor(DDI), indirect dependent industries(IDI). Research regions are 4 cities (Yosu, Yochun, Soonchun, Dongkwangyang) and 3 counties (Yochun, Seungju, Kwangyang).In the aspect of employment, the Yosu-Kwangyang harbor produced a good effect in these regions. In 1995, the rates of the dependence on harbor were showed up RI 1.63%, DBI 3.33%, IDI 15.99%, TOTAL 19.95%. In the Suture, the rates may be showed up various results as; in TOTAL rates, 33.59% in 2000, 44.95% in 2005, 48.03% in 2010, 49.82% in 2015.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.1-6
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• 2010

This study presents the practical design modification to improve the retracting performance of the pyro-typed high power pretensioner. 3 components of the pretensioner are redesigned and the usefulness of the design modification is verified by the experiment. During the pretensioning process, the gas blast generated from the gunpowder is transferred to the rack-pinion gear through the manifold. The rack-pinion gear is connected with the spool where the webbing is rolled up. According to the rotation of the pinion, the spool is turned and the webbing is winded. To help the gas blast flow well, the shape of the inner cross section of the manifold is changed. The spur gear design program is developed and used to find the best combination of the rack-pinion gear pair to increase the power transmission efficiency. The pinion guide is installed on the spool to prevent the vibration of the pinion. As a result of the experiment, the amount of the web retraction length is increased when every single design modification is applied. Therefore, the retracting performance of the pretensioner is considered to be improved if the presented design modifications are applied.

• Journal of Animal Science and Technology
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• v.62 no.3
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• pp.293-305
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• 2020

The difference in the breeding programs and population history may have diversely shaped the genomes of Korean native cattle breeds. In the absence of phenotypic data, comparisons of breeds that have been subjected to different selective pressures can aid to identify genomic regions and genes controlling qualitative and complex traits. In this study to decipher genetic variation and identify evidence of divergent selection, 3 Korean cattle breeds were genotyped using the recently developed high-density GeneSeek Genomic Profiler F250 (GGP-F250) array. The three Korean cattle breeds clustered according to their coat color phenotypes and breeding programs. The Heugu breed reliably showed smaller effective population size at all generations considered. Across the autosomal chromosomes, 113 and 83 annotated genes were identified from Hanwoo-Chikso and Hanwoo-Heugu comparisons, respectively of which 16 genes were shared between the two pairwise comparisons. The most important signals of selection were detected on bovine chromosomes 14 (24.39-25.13 Mb) and 18 (13.34-15.07 Mb), containing genes related to body size, and coat color (XKR4, LYN, PLAG1, SDR16C5, TMEM68, CDH15, MC1R, and GALNS). Some of the candidate genes are also associated with meat quality traits (ACSF3, EIF2B1, BANP, APCDD1, and GALM) and harbor quantitative trait locus (QTL) for beef production traits. Further functional analysis revealed that the candidate genes (DBI, ACSF3, HINT2, GBA2, AGPAT5, SCAP, ELP6, APOB, and RBL1) were involved in gene ontology (GO) terms relevant to meat quality including fatty acid oxidation, biosynthesis, and lipid storage. Candidate genes previously known to affect beef production and quality traits could be used in the beef cattle selection strategies.