• The korean journal of orthodontics
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• v.41 no.4
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• pp.255-267
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• 2011

Objective: The purpose of this study was to confirm the reliability of a cone beam computed tomography (CBCT)-generated panoramic view based on a CBCT 3D image and to find the most helpful 2D panoramic image compared with CBCT 3D image when examining the mesiodistal tooth axis. Methods: A test model was constructed according to cephalometric norms. The test model was repeatedly repositioned for CBCT and panoramic radiographic imaging. Panoramic radiographs were acquired at each of the following 3 occlusal plane positions: $-5^{\circ}$, $0^{\circ}$, and $+5^{\circ}$. Measurements of mesiodistal tooth axis in CBCT 3D image, CBCT-generated panoramic view, and panoramic radiographs were compared. Results: Compared with the CBCT-generated panoramic view, CBCT 3D image showed significant difference in the mesiodistal tooth axis in the premolars and no significant difference in the mesiodistal tooth axis in the incisors and canines. Mesiodistal tooth axis on the CBCT-generated panoramic view was significantly different from that on panoramic radiographs. Conclusions: CBCT-generated panoramic view can be a useful tool for evaluating mesiodistal tooth axis.

• The korean journal of orthodontics
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• v.41 no.4
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• pp.237-254
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• 2011

Objective: The purpose of this study was to compare the displacement patterns shown by finite element analysis when the maxillary anterior segment was retracted from different orthodontic miniscrew positions and different lengths of lever arms in lingual continuous and segmented arch techniques. Methods: A three dimensional model was produced, the translation of teeth in both models was measured and individual displacement was calculated. Results: When traction was carried out from miniscrews in the palatal slope, lingual tipping of crowns and extrusion of the maxillary anterior segment were found in both continuous and segmented arches as the lever arms were made shorter. With miniscrews in the midpalatal suture area, the displacement patterns were similar to the palatal slope, but bodily movement of the upper incisors was observed in both continuous and segmented arches with the lever arm at 20 mm. When lever arms were longer, there was less extrusion of the incisors and more buccal displacement of the canines. Such displacement was shown less in the continuous arch than the segmented arch. The second premolar showed crown mesial tipping and intrusion, and the molars showed distal tipping in the continuous arch. The posterior segment was displaced three dimensionally in the segmented arch, but the amount of displacement was less than the continuous arch. Conclusions: It is recommended that lever arms of 20 mm in length be used for bodily movement of the anterior segment. Use of continuous or segmented arches affect the displacement patterns and induce differences in the amount of displacement.

• The korean journal of orthodontics
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• v.37 no.2 s.121
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• pp.125-136
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• 2007

Objective: Soft tissue changes due to orthodontic treatment has large individual variation. Therefore continuous evaluation during treatment is required. Patients with fixed orthodontic appliances often wonder if their lip positions will change after the removal of brackets, but only a few studies exist on this topic. The objective of this study was to evaluate the changes of the lips and perioral soft tissue after bracket removal. Methods: The sample used in this study was 19 males and 33 females. Cephalometric X-rays were taken at 3 stages - T1 (before debonding), T2 (just after debonding), T3 (1.5 months after debonding). Results: The lower lip was retruded immediately after debonding (T2-T1), and 1.5 months after debonding (T3-T2). The mean amounts of retrusion from the vertical reference plane (sG perpendicular line) were about 0.38 mm for the upper lip and 0.88 mm for the lower lip. Immediately after debonding, lip retrusion of females was greater than that of males. During the post-debonding period, lower lip of males was retruded more than that of females. Conclusion: Lips are retruded after bracket removal, and there is no gender difference 1.5 months after debonding.

• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.1227-1259
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• 2014

This paper explores agricultural extension systems, extension challenges, research and extension models, governance structures of agricultural extension and advisory services in Sudan. Agricultural extension services in Sudan are provided by a variety of governmental department and corporation. The Technology Transfer and Extension Administration under the Ministry of Agriculture and Irrigation, had been launched during mid 2000's aims at making extension systems farmer driven and farmer accountable by way of new institutional arrangements for technology dissemination in the form of community participation approach at the state level, to make the extension reforms have the active participation of farmers/farmer groups. The main problem facing agricultural extension services in developing countries is poor link between extension organization and research. Both extension administration and Agricultural Research Corporation (ARC) are operating as departments of ministry of Agricultural and irrigation for very long time. There are three recommendations to achieve the effectiveness of the Agricultural Research Corporations (ARC) in reaching farmers. Firstly, extension staff members should be assigned to every ARC station. Secondly, the ARC might increase positions for Agricultural development specialist or Farming System Research (FSR) specialist. Their role would be to reflect the needed of farmer and translate them to the researchable topics. Thirdly, researcher should conduct more research on farmer's fields.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.6
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• pp.225-231
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• 2016

The valence band maximum (VBM) and conduction band minimum (CBM) of Al-doped GaInAsSb alloys substrated on GaSb are calculated by using an analytic approximation based on the tight binding method. The relative positions of the VBM and CBM between Al-GaInASSb and GaSb determine band alignement type, valence band offset (VBO) and conductin band offset (CBO) for the heterojunctions. In this study, aluminium doping is assumed to be substituted in the cation site and limited up to 20 % because it can easily oxidize and degrade materials. It is found that the Al-doped alloys exhibit type-II band alignments over the entire composition range and make the band gaps increase, whereas the VBO and CBO decrease. The decreasing rate of VBO is higher than that of CBO, which implies the Al components play a decisive role in controlling electrons at the interface. The Al-dopled GaInAsSb alloy has a direct band gap induced by $E({\Gamma})$ with a considerable distance from the E(L) and E(X), however, $E({\Gamma})$ approaches to E(L) and E(X) in the high Sb concentration (Sb > 0.7-0.8) which might affect the electron mobility and degrade the optical quality.

• Korean journal of communication and information
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• v.45
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• pp.296-340
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• 2009

The power of media has always been problematic in the countries of full press freedom. Originally, the media used to be an effective vehicle for communication within human beings. However, it exerts an overwhelming power toward human society. Through applying the well-known four dog models in terms of media function, this study attempts to examine how the press media in South Korea transformed themselves into another powerful independent organization or institution after regime shift in 1987. The whole editorials of four sampled newspapers were analyzed through frame analysis model. The ChosunIlbo, known as a conservative and pro-government paper, shows to take the role of supporting chaebol policies under Roh TaeWoo Administration. However, it criticizing sharply against the chaebol policies of Roh MooHyun Administration. The JoongangIlbo, known as a pro-chaebol paper, appears anti-government position through the entire four administrations in terms of chaebol policies. Particularly, it reveals hostile editorial coverage during the Roh MooHyun Administration. However, KyunghyangShinmun, currently known as a liberal paper, viewed somewhat complicated positions (see text in more detail) because of its ownership turbulence during the past twenty years. On the other hand, Hangyoreh, regarded as a progressive paper, keeps in supportive attitude consistently against the four sampled administrations as far as regulating each government policies for chaebols.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.5-19
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• 2003

A series of centrifuge model tests were conducted to investigate the behavior of piled bridge abutments subjected to lateral soil movements induced by approach embankments. The effect of clay layer depth and the rate of embankment construction on piled bridge abutments are the main focus of this study. Tests were performed for two loading types: (1) incremental loading applied in six lifts to the final embankment height; (2) instant loading corresponding to the final embankment height applied in one lift quickly. A variety of instrumentations such as LVDTs, strain gauges, earth pressure transducers, and pore pressure transducers are installed in designed positions in order to clarify the soil-pile interaction and the short- and long-term behavior for piled bridge abutments adjacent to surcharge loads. Based on the results of a series of centrifuge model tests, the distribution of lateral flow induced by staged embankment construction has trapezoidal distribution. The maximum lateral soil pressure is about 0.75$\gamma$H at surcharge loading stage, and about 0.35 $\gamma$H at over 80% consolidated stage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5C
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• pp.706-715
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• 2004

In this paper, to decide the watermark embedding positions and embed the watermark we use the subband tee structure which is presented in the wavelet domain and the edge information in the spatial domain. The significant frequency region is estimated by the subband searching from the higher frequency subband to the lower frequency subband. LH1 subband which has the higher frequency in tree structure of the wavelet domain is divided into 4${\times}$4 submatrices, and the threshold which is used in the watermark embedding is obtained by the blockmatrix which is consists by the average of 4${\times}$4 submatrices. Also the watermark embedding position, Keymap is generated by the blockmatrix for the energy distribution in the frequency domain and the edge information in the spatial domain. The watermark is embedded into the wavelet coefficients using the Keymap and the random sequence generated by LFSR(Linear feedback shift register). Finally after the inverse wavelet transform the watermark embedded image is obtained. the proposed watermarking algorithm showed PSNR over 2㏈ and had the higher results from 2％ to 8％ in the comparison with the previous research for the attack such as the JPEG compression and the general image processing just like blurring, sharpening and gaussian noise.

• Journal of the Korean Data and Information Science Society
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• v.27 no.3
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• pp.677-687
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• 2016

Among lots of sabermetric statistics for baseball batters' ability, the wins above replacement (WAR) is the most popular statistic in MLB. However, there exists a difficulty applying WAR to KBO, since KBO data do not have position adjustment, league adjustment and park factor which are essential in calculating WAR. In this paper, using five statistics for both KBO and MLB qualified batters, we propose hitting ability index (HAI), an alternative sabermetric indices to represent batters' ability. Comparing HAI with WAR of MLB batters, we evaluate the validity of HAI and then applied HAI to 2015 KBO data in which HAI is analyzed statistically with respect to different teams, ages, and positions. Moreover, the linear relationship between KBO batter's HAI and their annual salary is discussed. Grouping 46 KBO batters based on confidence region of the regression model for annual salary, we also statistically investigate batter's annual salary in these groups with respect to several factors.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.848-855
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• 2003

During concrete placement, the partially distributed load due to the concrete placement paths creates the lateral force in the connection parts of the shore. In order to restrain this lateral force, the nails must be used in the upper and lower connection parts of shores. But, for the convenience of the construction and dismantling of the shores, the workers hardly use the nails. In this case, the connections of shore cannot resist the shear force and rotation. And this situation may cause the collapse of form-shore system. Therefore, contact and spring models for the connection analysis of the form-shore systems are required. If we take into account this construction situation, we need to understand the effects of shear and rotation stiffness according to the several types of connection parts in shores as a case study. This study evaluates the shear and rotation stiffness of the connection parts of shores according to the variations of the lengths, numbers and positions of nails, and then presents the experimental results depending on the end conditions of shores. And, these results can be used as a spring model and critical load evaluation data for the connection analysis of form-shore system.