Earticle

The purpose of this paper is to understand the flow of force between the bracket system and roof structure in the korean traditional wooden buildings. The bracket and roof systems are one of the characteristics in korean traditional architecture. They are very important parts of structural components and normally understood as one system. The bracket systems considered are Dapogye and Chusimpogye and the roof systems are gable roof and hipped-and-gable roof. Generally the hipped-and-gable roof system is used with Dapogye bracket system and gable roof system with Chusimpogye. The full structures with roof, bracket and columns are analyzed with Finite Element Method(FEM). In this study, the connection of timber members is considered hinges and fully restrained for the simplicity of structural analysis. The four cases from the combination of two roof systems and two bracket systems are analyzed. From the strcutural analysis of those roof-bracket structures, the difference to two systems can be explained. The force flow shows the traditional assembly of roof and bracket system is much reasonable structures.

The purpose of this study is observes the change process of the Da-po from constructive traits of Beem and upper wooden frame structure. The constructive traits of Da-po and Beam could be classified with 3 types. It will be able to understand rationalization process of wooden frame structure.

Purpose: To investigate shear bonding strength between dental zirconia ceramics with different surface treatment and metal bracket. Methods: Zirconia ceramics(LAVA, 3M ESPE, USA) were divided to 4 groups according to their surface treatment; no surface treatment(G1), sand blasting(G2), silane coating(G3), and sand blasting+silane coating(G4). Specimens were bonded to metal bracket using resin bond(TransbondTMXT, 3M Unitek, USA). Shear bond strength was measured using universal test machine(3366 INSTRON. U.S.A) with cross head speed of 1 mm/min. Microstructural investigation for fracture surface was performed after shear test. Results: Shear bonding strengths of single surface treatment groups (G2 and G3) were higher than no treatment group(G1). Combined Treatment Group (G4) showed the highest shear bond strength of 9.15 . Microstructural observation shows that higher shear bonding strength was obtained when debonding was occurred at metal bracket/resin interface rather than zirconia ceramic/resin interface. Conclusion: Surface treatment of zirconia is necessary to obtain higher bonding strength. Combined treatment can be more effective when surface the surfaces are kept clean and homogeneous.

Interest in modular buildings has surged recently, leading to their construction at increasing heights. However, seismic performance evaluations for modular connections remain insufficient. Based on Jang's (2019) experimental research, this study validates an analytical model and conducts parametric analyses on the shear strength ratio between the panel zone and beam, and the width-to-thickness ratio of the bracket. When the panel zone-to-beam shear strength ratio was 1.5 or higher, plastic hinge formation shifted from the panel zone to the beam. Consequently, a shear strength ratio between 1.5 and 2.0 is recommended. Analysis of the bracket’s width-to-thickness ratio revealed local buckling in models with non-compact sections, suggesting that brackets in modular connections be designed with compact sections or greater to enhance structural performance.

Objective: The purpose of this study was to investigate whether extension of the custom base is necessary for enhancement of bond strength, by comparing the debonding forces and residual adhesives of 3 different lingual bracket systems. Methods: A total of 42 extracted upper premolars were randomly divided into 3 groups of 14 each for bonding with brackets having (1) a conventional limited resin custom base; (2) an extended gold alloy custom base: Incognito${TM}$; and (3) an extended resin custom base: KommonBase${TM}$. The bonding area was measured by scanning the bracket bases with a 3-dimensional digital scanner. The debonding force was measured with an Instron universal testing machine, which applied an occlusogingival shear force. Results: The mean debonding forces were 60.83 N (standard deviation [SD] 10.12), 69.29 N (SD 9.59), and 104.35 N (SD17.84) for the limited resin custom base, extended gold alloy custom base, and extended resin custom base, respectively. The debonding force observed with the extended resin custom base was significantly different from that observed with the other bases. In addition, the adhesive remnant index was significantly higher with the extended gold alloy custom base. Conclusions: All 3 custom-base lingual brackets can withstand occlusal and orthodontic forces. We conclude that effective bonding of lingual brackets can be obtained without extension of the custom base.

Objective: The purpose of this study was to compare the static (SFF) and kinetic frictional forces (KFF) of a computer-aided design and computer-aided manufacturing lingual bracket (CAD/CAM-LB) with those of conventional LB (Con-LB) and Con-LB with narrow bracket width (Con-LB-NBW) under 3 tooth displacement conditions. Methods: The samples were divided into 9 groups according to combinations of 3 LB types (CAD/CAM-LB [Incognito], Con-LB [7th Generation, 7G], and Con-LB-NBW [STb]) with 3 displacement conditions (no displacement [control], maxillary right lateral incisor with 1-mm palatal displacement [MXLI-PD], and maxillary right canine with 1-mm gingival displacement [MXC-GD]; n = 6/group). While drawing a 0.016-inch copper or super-elastic nickel-titanium archwire with 0.5 mm/min for 5 minutes in a chamber maintained at $36.5^{\circ}C$, SFF and KFF were measured. The Kruskal-Wallis method with Bonferroni correction was performed. Results: The Incognito group demonstrated the highest SFF, followed by the 7G and STb groups ([STb-control, STb-MXLI-PD, Stb-MXC-GD] < [7G-MXC-GD, 7G-MXLI-PD, 7G-control] < [Incognito-MXLI-PD, Incognito-control, Incognito-MXC-GD]; p < 0.001). However, there were no significant differences in SFF among the 3 displacement conditions within each bracket group. Within each displacement condition, the Incognito group demonstrated the highest KFF, followed by the 7G and STb groups ([STb-control, STb-MXLI-PD] < Stb-MXC-GD < 7G-MXLI-PD < [7G-control, 7G-MXC-GD] < [7G-MXC-GD, Incognito-MXLI-PD, Incognito-control] < [Incognito-control, Incognito-MXC-GD]; p < 0.001). MXC-GD exhibited higher KFFs than MXLI-PD in the same bracket group. Conclusions: The slot design and ligation method of the CAD/CAM-LB system should be modified to reduce SFF and KFF during the leveling/alignment stage.

Objective: To investigate how bracket slot size affects the direction of maxillary anterior tooth movement when en-masse retraction is performed in sliding mechanics using an induction-heating typodont simulation system. Methods: An induction-heating typodont simulation system was designed based on the Calorific Machine system. The typodont included metal anterior and resin posterior teeth embedded in a sticky wax arch. Three bracket slot groups (0.018, 0.020, and 0.022 inch [in]) were tested. A retraction force of 250 g was applied in the posterior-superior direction. Results: In the anteroposterior direction, the cusp tip of the canine in the 0.020-in slot group moved more distally than in the 0.018-in slot group. In the vertical direction, all six anterior teeth were intruded in the 0.018-in slot group and extruded in the 0.020- and 0.022-in slot groups. The lateral incisor was significantly extruded in the 0.020- and 0.022-in slot groups. Significant differences in the crown linguoversion were found between the 0.018- and 0.020-in slot groups and 0.018- and 0.022-in slot groups for the central incisor and between the 0.018- and 0.022-in slot groups and 0.020- and 0.022-in slot groups for the canine. In the 0.018-in slot group, all anterior teeth showed crown mesial angulation. Significant differences were found between the 0.018- and 0.022-in slot groups for the lateral incisor and between the 0.018- and 0.020-in slot groups and 0.018- and 0.022-in slot groups for the canine. Conclusions: Use of 0.018-in slot brackets was effective for preventing extrusion and crown linguoversion of anterior teeth in sliding mechanics.

This paper deals with on-Line detection of strip movement and real time positioning of brackets of EMD connected with it. Strip movement is detected by 4 line CCD camera and measured position correction value is inputted to motor position controller to control position of brackets.

본 연구에서는 배관계에 가해진 압력으로 인하여 변형된 배관에 의하여 영향을 받는 브라켓에 대하여 여러 가지 형상으로 모델링하여 유한요소해석을 통하여 브라켓의 형상변화가 변형특성에 미치는 영향을 고찰 하였고, 배관시스템의 브라켓의 강도 안전성을 확보하기 위하여 산업공학에서 쓰였던 다구찌방법을 도입하여 최적화 설계를 하는 것이 본 연구의 목적이다.

This study examined the structural behavior of bracket scaffolds reflecting the influence of bracket's deflection. Even though the supporting condition of bracket scaffolds is different to that of general earth-supported scaffolds, there is no clear standards about the installation of bracket scaffolds. To compare the structural behaviors of the earth-supported scaffolds without settlements in columns and those of bracket scaffolds installed on the bracket structure, the finite element analysis was performed. The results show that the differential settlement between the scaffold columns installed on the bracket was occurred due to the deflection of the bracket. The differential settlement gave birth to remarkable secondary stress to the scaffold columns. It is resonable to locate all scaffold columns on the brackets, and if unavoidable situation is faced at a site, the horizontal members should not placed alone without columns on the brackets. Moreover, the structural analysis should be performed to ensure structural safety of bracket scaffolds before installation. In addition, the location of wall connection to the structures is recommended to the scaffolds columns installed on the brackets.

본 연구는 소득공제에서 세액공제로 전환된 2014년 적용 소득세법의 개정이 소득계층별로 미치는 세 부담 차이를 분석한 것으로, 제5차 재정패널 자료 중 근로소득자 전체를 대상으로 하여 소득분위를 10분위로 구분하여 분석하였으며, 재정패널의 부족한 자료는 전수 자료인 국세통계연보를이용하여 분석하였다. 연구결과를 보면, 첫째, 특별공제 항목의 경우 2007년에 비하여 증가하였으며 특히 1인당 특별공제액은 근로소득자 전체의 평균 1인당 공제액보다 상위 10%의 평균 1인당 공제액이 2배 가까이큰 것으로 나타났다. 이는 세 부담에 역진적인 소득공제의 특성상 개정 전 소득공제제도는 고소득층이 저소득층에 비해 상대적으로 세 부담 측면에서 유리한 것을 보여주는 것이다. 둘째, 소득계층별 세 부담 차이를 분석한 결과 소득계층 10분위 중 5분위부터 2014년 적용 소득세법을 적용한 세부담액이 증가하는 것으로 나타났다. 이는 정부의 발표 및 기존 연구와 다른 결론으로 근로소득공제의 축소, 자녀세액공제로의 통합 및 세액공제 전환된 항목 중 일부 항목의 12% 세액공제율 적용등으로 총급여액 4,600만 원의 소득수준부터 세 부담이 증가되는 것으로 나타났다. 셋째, 고소득층으로 갈수록 세 부담이 더욱 증가하여 고소득층의 실효세율이 증가하므로 세 부담 형평성은 증가될 것으로 판단된다. 결과적으로 소득공제제도가 갖는 단점인 세 부담의 역진성의 완화를 위해 세액공제도로 전환한점은 바람직한 세제개편방향이지만, 소득공제제도 전체에 대한 점검이 부족했던 것으로 판단된다. 즉, 소득공제제도는 조세형평성 차원에서 다양한 납세자의 소득, 소비 등의 패턴이 잘 반영될 수있어야 하므로, 공제항목별 특성을 고려한 후 다양한 소비 형태 등이 반영되어 응능부담의 원칙이실현되도록 소득공제제도 전체를 점검할 것을 제안하고자 한다.

This study is intended to analyze the difference in tax burden by income bracket after revision of income tax law from tax deduction to tax credit system, taking effect in 2014. To that end, income bracket of all income earners, among the 5th National Survey of Tax and Benefit(NaSTab) data, was classified into 10 categories and insufficient data was supplemented by statistics yearbook issued by National Tax Service. Viewing the analysis, first, items subject to special deduction was increased from 2007 and particularly, per capita deduction of top 10% almost doubled the average per capital deduction of all income earners, which showed that former tax deduction system was relatively favorable to high－income earners than low－income earners in terms of tax burden because of regressive tax deduction characteristics. Second, according to analysis of difference in tax burden by income bracket, tax burden by revised 2014 law was increased from the 5th grade among 10 categories, which was different from government’s announcement and previous studies, showing that tax burden of the category with annual salary totaled ￦46 mil was increased due to reduced income tax deduction, integrated child tax deduction and application of 12% deduction rate of some items that were changed to tax credit system. Third, the higher the income the greater the tax burden, indicating effective tax rate of higher－income bracket was increased more and accordingly tax burden fairness is expected to improve. Saying in conclusion, change to tax credit system to ease regressive tax burden problem which the tax deduction system had was desirable but overall review of deduction & exemption system seemed not to be sufficient. That is, deduction & exemption system shall be able to incorporate the earnings and spending pattern of the taxpayers and thus it’s recommended to review deduction & exemption system from overall standpoint to incorporate a variety of spending considering the characteristics by deduction, thereby accomplishing the “ability－to－pay principle”.

2005년부터 국가적 차원에서 전국적으로 운영되고 있는 사이버가정학습은 지역간 교육격차 해소와 사교육비 경감이라는 목적을 가지고 운영되고 있다. 이에 사이버가정학습이 목적에 맞게 잘 운영되고 있는지에 대한 분석 연구는 매우 필요하다. 따라서 본 논문은 사이버가정학습의 교육적 효과성 및 만족도를 평가하는 모델을 제안하고 저소득층 학생을 대상으로 만족도와 효과성을 분석하여 사이버가정학습이 보다 효과적으로 운영되도록 지원하는데 목적이 있다. 아울러 세부적인 연구내용은 다음과 같이 요약할 수 있다. 첫째, 기존 연구를 바탕으로 사이버가정학습 평가모델을 제안하였다. 둘째, 온라인 설문조사를 통해 사이버가정학습에 대한 저소득층 학생들의 만족도와 효과성, 개선사항을 조사하였다. 셋째, 성별, 소속지역, 소속학급, 학급구성방식 등 배경요인별에 따른 만족도와 효과성을 비교․분석하였다. 끝으로 본 논문은 저소득층 학생들을 대상으로 이러닝 효과성과 만족도를 측정 분석하였다는데 의의가 있으며, 향후 사이버가정학습이 교육기회 균등 및 교육격차 해소라는 본래의 목적을 살리고 보다 나은 교육서비스가 되기 위한 자료로 활용될 수 있을 것으로 기대된다.

Since 2005, Cyber home learning systems(CHLS) have been run with the purpose of clearing up the regional disparity and reducing the private education cost. At this point, it is necessary to have the analysis on the satisfaction and effectiveness awareness of the CHLS. The goal of this paper is to suggest an evaluation model for satisfaction and pedagogical effectiveness of CHLS and to support the management of satisfaction and effectiveness awareness of the CHLS for the low-income bracket children. Our major contributions can be summarized as follows: First, we present an evaluation model of satisfaction and effectiveness awareness of the CHLS for the low-income bracket children. Second, we survey the satisfaction, effectiveness awareness and improvement facts from the students who divided according to their sex, residence area and classes and compare with suggesting evaluation models. This paper is to find the measurement of the satisfaction and effectiveness awareness of the CHLS for the low-income bracket children. Furthermore, we can use this model as a material to balance the education opportunity, which is the purpose of CHLS, and abolish the education differentials.