• The Journal of Advanced Prosthodontics
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• 제2권2호
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• pp.39-45
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• 2010

PURPOSE. The aim of this study was to determine differences in shear bond strength to human dentin using immediate dentin sealing (IDS) technique compared to delayed dentin sealing (DDS). MATERIALS AND METHODS. Forty extracted human molars were divided into 4 groups with 10 teeth each. The control group was light-cured after application of dentin bonding agent ($Excite^{(R)}$ DSC) and cemented with $Variolink^{(R)}$. II resin cement. IDS/SE (immediate dentin sealing, $Clearfil^{TM}$ SE Bond) and IDS/SB (immediate dentin sealing, $Adapter^{TM}$ Single Bond 2) were light-cured after application of dentin bonding agent ($Clearfil^{TM}$ SE Bond and $Adapter^{TM}$ Sing Bond 2, respectively), whereas DDS specimens were not treated with any dentin bonding agent. Specimens were cemented with $Variolink^{(R)}$. II resin cement. Dentin bonding agent ($Excite^{(R)}$. DSC) was left unpolymerized until the application of porcelain restoration. Shear strength was measured using a universal testing machine at a speed of 5 mm/min and evaluated of fracture using an optical microscope. RESULTS. The mean shear bond strengths of control group and IDS/SE group were not statistically different from another at 14.86 and 11.18 MPa. Bond strength of IDS/SE group had a significantly higher mean than DDS group (3.14 MPa) (P < .05). There were no significance in the mean shear bond strength between IDS/SB (4.11 MPa) and DDS group. Evaluation of failure patterns indicates that most failures in the control group and IDS/SE groups were mixed, whereas failures in the DDS were interfacial. CONCLUSION. When preparing teeth for indirect ceramic restoration, IDS with $Clearfil^{TM}$ SE Bond results in improved shear bond strength compared with DDS.

• Clinics in Shoulder and Elbow
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• 제19권3호
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• pp.143-148
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• 2016

Background: The purpose of our study was to evaluate the accuracy of reduction based on postoperative computed tomography (CT) images after arthroscopic stabilization using tightrope system for unstable distal clavicle fracture. Methods: Twelve patients with distal clavicle fracture combined with coracoclavicular (CC) ligament injury (type II, V) who received arthroscopically assisted fixation using a flip button device were evaluated for accuracy of reduction using 3-dimensional postoperative CT scan by measuring the degree of distal clavicular angulation and clavicular shortening. Results: Immediate postoperative plain radiograph confirmed restoration of the CC distance (CCD) in 10 patients. At final follow-up, the CCD remained reduced anatomically on plain radiographs in these patients. All patients showed excessive posterior angulation and shortening compared to the opposite side. The average Constant score recovered to 94.8 at final follow-up. Conclusions: Indirect reduction and arthroscopic subacromial approach with flip button fixation of unstable distal clavicle fractures demonstrated favorable clinical results despite unavoidable posterior angulation of distal clavicle and shortening the total length of clavicle.

• Smart Structures and Systems
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• 제32권1호
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• pp.49-59
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• 2023

A bridge transportation network supplies products from various source nodes to destination nodes through bridge structures in a target region. However, recent frequent earthquakes have caused damage to bridge structures, resulting in extreme direct damage to the target area as well as indirect damage to other lifeline structures. Therefore, in this study, a surrogate model-based comprehensive framework to estimate the seismic resilience of bridge transportation networks is proposed. For this purpose, total system travel time (TSTT) is introduced for accurate performance indicator of the bridge transportation network, and an artificial neural network (ANN)-based surrogate model is constructed to reduce traffic analysis time for high-dimensional TSTT computation. The proposed framework includes procedures for constructing an ANN-based surrogate model to accelerate network performance computation, as well as conventional procedures such as direct Monte Carlo simulation (MCS) calculation and bridge restoration calculation. To demonstrate the proposed framework, Pohang bridge transportation network is reconstructed based on geographic information system (GIS) data, and an ANN model is constructed with the damage states of the transportation network and TSTT using the representative earthquake epicenter in the target area. For obtaining the seismic resilience curve of the Pohang region, five epicenters are considered, with earthquake magnitudes 6.0 to 8.0, and the direct and indirect damages of the bridge transportation network are evaluated. Thus, it is concluded that the proposed surrogate model-based framework can efficiently evaluate the seismic resilience of a high-dimensional bridge transportation network, and also it can be used for decision-making to minimize damage.

• 한국환경복원기술학회지
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• 제8권2호
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• pp.33-40
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• 2005

The objective of this research was to find an indirect method to estimate spectral reflectance and NDVI(Normalized Difference Vegetation Index) efficiently, using the spectroradiometer and NOAA AVHRR satellite data. For collecting RS base data, used spectro-radiometer that measures reflection characteristics between 300~1,100nm was used and measured the reflection of vegetation from paddy rice during the growing season at Chungbuk national university's farm in 2002. The feasibility of detecting the temporal variation in the spectral reflectance and NDVI in paddy rice were conducted on eight growth stages. AVHRR data were collected in eight different months over a one year period in 2002. The results were compared with those obtained by analyzing NDVI characteristics. The spectral reflectance and NDVI of paddy rice have a great effect on the growth condition. Considerably, NDVI was increased by developing muscle fiber tissue at the near infrared wavelength until the Booting stage. Then the NDVI increased until the Maturity stage and then decreased until harvest. The highest month was at July and the lower month was at March. The difference NDVI analysis using March and another months data was conducted, the results were provided information on the growth condition of crops.

• Restorative Dentistry and Endodontics
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• 제33권5호
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• pp.443-451
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• 2008

이 연구의 목적은 단일 접착 과정의 레진 시멘트인 Maxcem을 제조사의 지시대로 사용하는 것과 부가적인 산 부식과정을 추가하여 접착을 시도함에 있어 그 임상적 접착 강도를 알아보고자 하는 것이었다. 치아 우식에 이환되지 않은 120개의 상하악 구치를 사용하여 간접 수복물 제작을 위한 와동을 형성하고 금인레이와 간접복합레진(Synfony) 수복물을 제작하였다. 실험군은 수복물의 종류마다 사용한 시멘트의 종류와 방식에 따라 세 군으로 분류하였다. 최종적으로 102개의 와동 시편에 수복물의 접착을 위해 Maxcem을 사용한 군, 인산으로 부가적인 산부식 후에 Maxcem을 사용한 군, 그리고 대조군으로 다단계 전-산부식 (total-etching) 시멘트인 Variolink II 를 사용하여 접착한 실험군으로 각 군 당 17개씩으로 분류하였다. 자체 제작한 만능시험기로 push-out 접착 강도를 측정하고 와동 접착 표면적으로 나누어 단위 면적당 결합력으로 산출하였다. SPSS 12.0K 프로그램을 사용하여 one-way ANOVA와 95% 신뢰도의 Scheffe's Test로 각 실험군의 접착력를 비교하였다. 이 실험의 조건하에서는 Maxcem을 사용할 때, 간접수복물의 종류에 관계없이, 제조사의 지시 외에 부가적인 산부식 과정은 접착 강도를 감소시키는 역효과를 유발하였으며 더욱 강한 접착력을 필요로 하는 경우는 다단계 접착제를 사용하여 산부식 과정과 접착제 적용, 시멘트 도포 등을 분리하여 사용하는 것이 바람직하다.

• 한국환경복원기술학회지
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• 제19권1호
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• pp.185-193
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• 2016

Purpose of this study is to classify damaged lands according to the cause of the damage and their influences based on characteristic of the damaged lands in DeMilitarized Zone(DMZ) area, and utilize this study as a fundamental study for establishment of ecosystem restoration system. Literature review and field survey have been conducted to review the damage status of DMZ area. For field survey, first year and second year have been conducted, in which type of the damage has been reviewed in this study. In the result, types of damage have been classified into 6 categories: 'alteration of initial landform', 'loss of surface layer', 'land pollution', 'alteration of soil chemical property', 'decline of vegetation', and 'invasion of foreign species'. Restoration for each damage type is as following. First, for alteration of initial landform, the land is restored to the original landform prior to the damage and connection to surrounding ecosystem is considered. Second, for loss of surface layer, lost surface layer is restored or further loss is prevented with stabilization. Third, for land pollution, source of the pollution is eradicated or self-circulation with purification of polluted land is encouraged. Fourth, for alteration of soil chemical property, soil is restored of its original property with eradication of the pollution source and improvement of soil. Fifth, for decline of vegetation, current vegetation and anticipated alteration in future are considered and number of wild species is to be increased based on structure and characteristic of nearby vegetation. Sixth, for invasion of foreign species, prevention of dominance by risky species and facilitation ecological stability with ecological management are to be considered. Influence according to the cause of damage has occurred in secondary(indirect) influence or simultaneous occurrence of several damage types. Considering all these aspects, when type of the damage is complex, restoration process for each of former mentioned 6 damage types with solitary influence should be considered in unison.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 춘계학술대회
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• pp.235-237
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• 2001

;Dentistry has benefited from tremendous advances in technology with the introduction of new techniques and materials, and patients are aware that esthetic approaches in dentistry can change one's appearance. Increasingly. tooth-colored restorative materials have been used for restoration of posterior teeth. Tooth-colored restoration for posterior teeth can be divided into three categories: 1) the direct techniques that can be made in a single appointment and are an intraoral procedure utilizing composites: 2) the semidirect techniques that require both an intraoral and an extraoral procedure and are luted chairside utilizing composites: and 3) the indirect techniques that require several appointments and the expertise of a dental technician working with either composites or ceramics. But, resin restoration has inherent drawbacks of microleakage. polymerization shrinkage, thermal cycling problems. and wear in stress-bearing areas. On the other hand, Ceramic restorations have many advantages over resin restorations. Ceramic inlays are reported to have less leakage than resin restoration and to fit better. although marginal fidelity depends on technique and is laboratory dependent. Adhesion of luting resin is more reliable and durable to etched ceramic material than to treated resin composite. In view of color matching, periodontal health. resistance to abrasion, ceramic restoration is superior to resin restorationl. Materials which have been used for the fabrication of ceramic restorations are various. Conventional powder slurry ceramics are also available. Castable ceramics are produced by centrifugal casting of heat-treated glass ceramics. and machinable ceramics are feldspathic porcelains or cast glass ceramics which are milled using a CAD/CAM apparatus to produce inlays (for example, Cered. They may also be copy milled using the Celay apparatus. Pressable ceramics are produced from feldspathic porcelain which is supplied in ingot form and heated and moulded under pressure to produce a restoration. Infiltrated ceramics are another class of material which are available for use as ceramic inlays. An example is $In-Ceram^{\circledR}$(Vident. California, USA) which consists of a porous aluminum oxide or spinell core infiltrated with glass and subsequently veneered with feldspathic porcelain. In the 1980s. the development of compatible refractory materials made fabrication easier. and the development of adhesive resin cements greatly improved clinical success rates. This case report presents esthetic ceramic inlays for posterior teeth.teeth.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.334-346
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• 1997

Incidence of using esthetic composite resin in the posterior area is increasing but there were lots of inconsistent reports about their microleakage and marginal adaptation. The purpose of this study was to evaluate the differences of microleakage and marginal adaptation according to restorative techniques. 30 cavities with enamel gingival margin were prepared and restored with 3 types of composite resin [Z-100($Scotchbond^{TM}$ MP), AELITEFIL ($Onestep^{TM}$), Her culite XRV(Fuji BOND LC)] in direct technique and another 30 cavities were restored with preformed CR inlays and 3 different modern resin and resin-modified GI cements (Superbond C&B, Choice, Fuji Duet). Samples were chemically stressed in 75% ethanol for 24 hours and were thermocycled (5-$55^{\circ}C$(500 times. The degree of microleakage through proximal and gingival margins was examined by 1 % MB dye and the degree of marginal adaptation by examining the margins via SEM. The following results were obtained ; 1. In direct groups, Herculite XRV [Fuji BOND LC, 35.13 (15.50) %] group showed statistically different, less microleakage than Z-100 [$Scotchbond^{TM}$ MP, 72.91 (16.91 %] group and AELITEFIL [One-step, 93.73 (13.66) %] group (p<0.05). 2. In indirect groups, the degree of microleakage in Mean(S.D.) were: Super bond C & B [39.00 (24.35) %], Choice [57.19 (33.80) %], Fuji Duet [58.22 (40.36) %]. But there was no significant difference. 3. There was no significant difference between resin cement and resin-modified GI cement. 4. There were gaps at the interface with the tooth structure, but no gap was seen at the interface with restoration in all specimens. 5. In direct groups, Herculite XRV(Fuji BOND LC) group made little gap compared with other groups, but 40-$50{\mu}m$ thickness of bonding agent, Fuji BOND LC, looked like a cement used in indirect technique. 6. All indirect groups showed a variety of cement thickness, from less than $20{\mu}m$ to over $100{\mu}m$ and that dimension of buccal/lingual margin was less than that of gingival margin.

• 한국습지학회지
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• 제15권2호
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• pp.159-164
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• 2013

4대강 살리기 사업은 막대한 공적재원이 투입된 대규모 국책사업으로서 지역경제 활성화는 사업의 여러 가지 목적 중 하나임에 틀림없다. 이에 본 논문에서는 4대강 살리기 사업의 지역경제 파급효과를 추정하되, 지역고용 창출효과 및 지역소득 창출효과라는 두 가지 주제에 초점을 맞추고자 한다. 지역고용 창출효과를 산정하기 위해 간접적 유발효과는 제외하고 직접적인 고용량을 조사하여 제시한다. 다음으로 대규모 전국 설문조사를 통해 가계소비, 가계소득, 지역내 소비율 등에 대한 정보를 수집하여 소비함수를 추정한 후 이로부터 한계소비성향을 추정하여, 거시경제학의 승수이론에 근거하여 지역소득 창출효과를 분석한다. 분석결과 2009년 초부터 2011년 8월 25일까지 4대강사업으로 인해 신규로 고용인원은 46,628명이었으며, 2009년 초부터 2011년 말까지의 4대강사업비 투입으로 인해 지역의 소득은 약 25조원이 새롭게 창출된 것으로 판단된다.

• 한국환경복원기술학회지
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• 제11권2호
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• pp.123-132
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• 2008

The problems caused by new biological organisms in Ogasawara Island of Japan include : (1) loss of native species' habitats and extinction of native species due to the multiplication of invasive species; (2) reduction of native species and confusion in the food chain in result of invasive species' predation; (3) confusion in genes due to hybridization of new and native plants; and (4) destruction of ecosystem and erosion of earth due to rapid increase of invasive species. The natural ecosystem of preserved areas in Korea is constantly confused and destroyed by new animals and plants, but Korea does not has any solutions because new animals and plants rarely affect human lives. Invasive species are manually introduced by humans and are considered disasters caused by humans. Korea is in desperate need of campaigns as the general public does not understand the seriousness of the destruction and confusion of natural ecosystem caused by new biological organisms and their indirect/direct influences on humans. It is necessary to evaluate the biological characteristics, ecological influence, and harms of invasive species in preserved areas to establish a system to manage invasive species and plan the priority removal of species that are highly harmful and locally distributed. Manual removal and suppression of new biological organisms that cause problems is effective, but it takes cost, effort, and time. Therefore, we would need to research and develop the most efficient and effective techniques and measures to manage invasive species in our ecosystem.