• Ocean Science Journal
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• v.40 no.4
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• pp.191-200
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• 2005

In this study an analytical tide model of uniform width with three sub-regions is presented. The three-subregions model takes into account step-like variations in depths in the direction of the channel as a way to examine the $M_2$ tide of the East China Sea (ECS) as well as the Yellow Sea (YS). A modified Proudman radiation condition has been applied at the northern open head, while the sea surface elevation is specified at the southern open boundary. It is seen that, due to the presence of an abrupt change in depth, co-amplitude lines of the $M_2$ tide are splitted to the east and west near the end of the ECS shelf region. Variations in depths, bottom friction and the open head boundary conditions all contribute to the determination of formation of amphidromes as well as overall patterns of $M_2$ tidal distribution. It is seen that increasing water depth and bottom friction in the ECS shelf results in the westward shift of the southern amphidrome. There is however no hint at all of the well-known degenerated tidal pattern being formed. It is inferred that a lateral variation of water depth has to be somehow incorporated to represent the tidal patterns in ECS in a realistic manner. Regarding the radiation factor introduced by Fang et al. (1991), use of a value larger than one, possibly with a phase shift, appears to be a proper way of incorporating the reflected waves from the northern Yellow Sea (NYS).

• Nuclear Engineering and Technology
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• v.41 no.9
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• pp.1143-1156
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• 2009

The SPACE code that is based on a multi-dimensional two-fluid, three-field model is under development for licensing purposes of pressurized water reactors in Korea. Among the participating research and industrial organizations, KAERI is in charge of developing the physical models and correlation packages for the constitutive equations. This paper introduces a developed wall-to-fluid heat transfer package for the SPACE code. The wall-to-fluid heat transfer package consists of twelve heat transfer subregions. For each sub-region, the models in the existing safety analysis codes and the leading models in literature have been peer reviewed in order to determine the best models which can easily be applicable to the SPACE code. Hence a wall-to-fluid heat transfer region selection map has been developed according to the non-condensable gas quality, void fraction, degree of subcooling, and wall temperature. Furthermore, a partitioning methodology which can take into account the split heat flux to the continuous liquid, entrained droplet, and vapor fields is proposed to comply fully with the three-field formulation of the SPACE code. The developed wall-to-fluid heat transfer package has been pre-tested by varying the independent parameters within the application range of the selected correlations. The smoothness between two adjacent heat transfer regimes has also been investigated. More detailed verification work on the developed wall-to-fluid heat transfer package will be carried out when the coupling of a hydraulic solver with the constitutive equations is brought to completion.

• Investigative Magnetic Resonance Imaging
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• v.23 no.3
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• pp.228-240
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• 2019

Purpose: The aim of this study is to evaluate the T2 value of the articular cartilage of the glenohumeral joint in rotator cuff disease displayed on 3.0T MRI and to apply it in clinical practice. Materials and Methods: This study involved sixty-two patients who underwent shoulder MRI containing T2 mapping. The mean T2 value was measured by placing a free hand ROI over the glenoid or humeral cartilage from the bone-cartilage interface to the articular surface on three consecutive, oblique coronal images. The drawn ROI was subsequently divided into superior and inferior segments. The assessed mean T2 values of the articular cartilage of the glenohumeral joint were compared and evaluated based on the degree of rotator cuff tear, the degree of fatty atrophy of the rotator cuff, and the acromiohumeral distance. Results: ICC values between two readers indicated moderate or good reproducibility. The mean T2 value for the articular cartilage of the glenoid and humeral head cartilage failed to show any significant difference based on the degree of rotator cuff tear. However, the mean T2 values of articular cartilage, based on fatty atrophy, tended to be higher in fatty atrophy 3 or fatty atrophy 4 groups while some subregions displayed significantly higher mean T2 values. There was no correlation between the acromiohumeral distance and the mean T2 values of the articular cartilage of the glenoid and humeral head. Conclusion: T2 mapping of the glenohumeral joint failed to show any significant difference in quantitative analysis of the degenerative change of the articular cartilage based on the degree of rotator cuff tear. However, it also offers quantitative information on the degenerative change of cartilage of the glenohumeral joint in patients with rotator cuff tear and severe fatty atrophy of the rotator cuff.

• Korea Trade Review
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• v.42 no.1
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• pp.217-236
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• 2017

The purpose of this study is to analyze the effects of IFDI on the regional growth of 16 subregions in Korea during 2000~2014 by applying the System GMM. As a result of the analysis, the IFDI flowed into Korea has showed a positive effect on regional economic growth such as capital formation, job creation, and export expansion. but import has showed a negative effect. and Human capital has showed a positive effect but not statistically significant. meanwhile, IFDI which was flowed in the regions has showed a positive effect on the GRDP of DK regions including Daegu and Kyongbuk, while the GRDP of Metropolitan including Seoul, Incheon and Gyeonggi and BUK regions including Busan, Ulsan, Kyongnam has showed a negative effect. there were observed similar trends in the complementarities between IFDI inflows and human capital. This study has confirmed that IFDI flows into Korea are an important factor for regional growth, but the growth effect on GRDP in the region differs according to regional characteristics. Therefore, this study has suggested that it is urgent to reorganize the industrial structure along with the IFDI attraction strategy suitable for regional characteristics in order to expand the growth effect of IFDI flowed into the regions.

• The Korean Journal of Applied Statistics
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• v.36 no.5
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• pp.473-488
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• 2023

Gangwon-do is one of Korea's most popular tourist destinations, with varying tourism demands and trends across its subregions. It is crucial to identify the characteristics of tourism in each area and compare the tourism patterns over time to devise policies that revitalize tourism in each local government and promote balanced development across regions. In this paper, we classify the regions in Gangwon-do based on tourism data from the last four years and analyze the tourism pattern of each region using the non-Euclidean additive model proposed by Jeon et al. (2021). The model incorporates the proportions of visitors by age groups and the proportions of navigation searches by destination types as two covariates, and the proportions of tourism expenditure types as a response variable. We estimate the model using the smooth-backfitting method and coordinate-wise bandwidth selection. The results are visualized in ternary plots, and changes in tourism patterns over time are analyzed by comparing the ratios of prediction errors to fitting errors.

• Journal of Ginseng Research
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• v.28 no.2
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• pp.94-103
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• 2004

Korean red ginseng is known to have anti-stress and memory enhancing effects. Recent studies suggested that stress-induced inhibition of adult neurogenesis in hippocampus may contribute, in part, to decreased negative feedback inhibition of HPA axis. In order to elucidate the mechanism of Korean red ginseng in anti-stress and memory enhancing effects, we observed the effects of repeated treatment of Korean red ginseng total saponin (GTS, 50 mg/kg, i.p.) in response to repeated unpredictable stress for 10 days. Male Sprague-Dawley rats (230 - 260 g) received with either GTS (50 mg/kg, i.p.) or vehicle (1 ml/kg, i.p.) 1 h before stress for 10 days. Rats were injected with bromodeoxyuridine (BrdU, 50 mg/kg, i.p.) 16-18 he after last stress procedure, and were sacrificed 2 hr later by perfusion. Immunohistochemistry of BrdU was done to measure proliferation of neural progenitor cells in hippocampus, which was used as an index of neurogenesis. Repeated GTS treatment for 10 days increased neurogenesis in subgranular zone area of dentate gyrus (SGZ), but not hilus, compared with vehicle-treated rats. Repeated unpredictable stress did not affect the neurogenesis compared with controls, while repeated GTS treatment increased neurogenesis in SGZ in repeated unpredictable stress-exposed group. BDNF mRNA was also measured in subregions of hippocampus by in situ hybridization. BDNF mRNA expression in CA3 and CA1 pyramidal cell layer was increased by repeated GTS treatment but not in dentate granule cell layer. Repeated unpredictable stresses significantly decreased BDNF mRNA expression in all subregions of hippocampus, but repeated GTS treatment did not prevent stress-induced BDNF mRNA downregulation. Given that repeated GTS treatment increased proliferation of neural progenitor cells in repeated unpredictable stress-exposed rats in the presence of decreased BDNF mRNA expression in dentate granule cell layer, it raise the possibility that BDNF may not playa significant role in GTS-mediated increase of neurogenesis in adult rat hippocampus. Also, these results suggest that repeated GTS treatment increased neurogenesis of SGZ and BDNF mRNA expression, which may account for memory enhancing effect of Korean red ginseng. In addition, repeated GTS treatment appears not to have anti-stress effects in terms of neurotrophin, but GTS-mediated increase of neurogenesis in hippocampus may contribute to increase negative feedback inhibition of HPA axis.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.414-427
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• 2022

This study aims to analyze the color distribution of maxillary permanent incisors in Korean pediatric patients and determine the effects of age and root developmental stage on tooth color. The L^*a^*b^* values of 404 sound and fully erupted maxillary incisors without dental caries, restorations, trauma history or discoloration from 101 Korean patients between ages 7 and 15, with a mean age 10.0 ± 1.5, were analyzed with a spectrophotometer. CIE L^*a^*b^* values were 84.01, 0.17, and 24.07 in maxillary central incisors, and 82.33, 0.31, and 25.99 in maxillary lateral incisors. L^* values of maxillary central incisors were higher, and b^* values of maxillary central incisors were lower than those of maxillary lateral incisors (p < 0.001). The color differences among the subregions exceeded the clinical perceptibility threshold in both of the maxillary central and lateral incisors. L^* value for children at age 10 and younger was 84.13 in maxillary central incisors and 84.04 in maxillary lateral incisors, and those of older patients were 80.62 and 80.56, respectively. L^* value of maxillary incisors of children at age 10 and younger was significantly higher than that of older patients. The root developmental stage did not affect tooth color. This study suggests that the color differences between maxillary central and lateral incisors and among the subregions of a tooth and the effects of age should be considered for aesthetic restorations of permanent incisors in pediatric patients.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.204-211
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• 2020

This study investigates the 17 ordinances on the improvement of labor condition and status of social workers in the metropolitan city of Busan that has 16 administrative borough, or gu, and a central headquarter, and further verifies its implementation. Researchers identified the presence of 9 articles in each ordinances, followed by data request being made to all the administrative offices for their implementation. As a result, the articles on obligation, research on the actual condition, support plan and committee establishment have been excluded in many gus, which were in default of implementation or slower than ordinances stipulate. It is suggested that statements about the obligation of the head officers, preceding research on the actual condition before support plan and committee establishment should be made in the independent articles. Regarding its implementation, ordinances are required to have a regulatory power through penalty, reflect the actual demands of social workers in the field and go through a regular evaluation and monitoring on its implementation in order for purpose accomplishment.

• Journal of KIISE:Software and Applications
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• v.33 no.4
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• pp.402-410
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• 2006

This paper presents a method for feature based block motion estimation that uses multi -resolution image sequences to obtain the panoramic images in the continuous ultrasound image sequences. In the conventional block motion estimation method, the centers of motion estimation blocks are set at the predetermined and equally spaced locations. This requires the large blocks to include at least one feature, which inevitably requires long estimation time. In this paper, we propose an adaptive method which locates the center of the motion estimation blocks at the feature points. This make it possible to reduce the block size while keeping the motion estimation accuracy The Harris-Stephen corner detector is used to get the feature points. The comer points tend to group together, which cause the error in the global motion estimation. In order to distribute the feature points as evenly as Possible, the image is firstly divided into regular subregions, and a strongest corner point is selected as a feature in each subregion. The ultrasound Images contain speckle patterns and noise. In order to reduce the noise artifact and reduce the computational time, the proposed method use the multi-resolution image sequences. The first algorithm estimates the motion in the smoothed low resolution image, and the estimated motion is prolongated to the next higher resolution image. By this way the size of search region can be reduced in the higher resolution image. Experiments were performed on three types of ultrasound image sequences. These were shown that the proposed method reduces both the computational time (from 77ms to 44ms) and the displaced frame difference (from 66.02 to 58.08).

• Journal of KIISE:Databases
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• v.33 no.5
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• pp.495-512
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• 2006

Recently, researches on a future position prediction of moving objects have been progressed as the importance of the future position retrieval increases. New index structures are required to efficiently retrieve the consecutive positions of moving objects. Existing index structures significantly degrade the search performance of the moving objects because the search operation makes the unnecessary extension of the node in the index structure. To solve this problem, we propose a space partition based index structure considering the mobility of moving objects. To deal with the overflow of a node, our index structure first merges it and the sibling node. If it is impossible to merge them, our method splits the overflow node in which moving properties of objects are considered. Our index structure is always partitioned into overlap free subregions when a node is split. Our split strategy chooses the split position by considering the parameters such as velocities, the escape time of the objects, and the update time of a node. In the internal node, the split position Is determined from preventing the cascading split of the child node. We perform various experiments to show that our index structure outperforms the existing index structures in terms of retrieval performance. Our experimental results show that our proposed index structure achieves about $17%{\sim}264%$ performance gains on current position retrieval and about $107%{\sim}19l%$ on future position retrieval over the existing methods.