• 융복합기술연구소 논문집
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• 제1권1호
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• pp.41-47
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• 2011

With the world-wide demand on the emission minimization, the needs on the diesel aftertreatment devices with high efficiency are also increasing. In order to effectively develop or design a high-performance diesel particulate filter, a clear understanding on the deposition and regeneration mechanism is required. In the present study, a theory on the lumped parameter model for wall-flow type diesel particulate filters is described focusing on the deposition efficiency, pressure drop inside the filter. The fourth order explicit Runge-Kutta method is utilized for the mass flow rate computation. Engine operation modes with controlled and uncontrolled regeneration options are selected. The computational lumped parameter model is validated by comparing the computed results with the measured data.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2005년도 제45회 종합학술대회 연제초록
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• pp.163-164
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• 2005

• 한국환경과학회지
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• 제12권7호
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• pp.745-751
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• 2003

The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of nutrients and net uptake(or regeneration) rate of nutrients in Kamak Bay for scenario analysis to find proper management plan. The estimation results of the physical process in terms of nutrients shelved that transportation of nutrients is dominant in surface level while accumulation of nutrients is dominant in bottom level. In the case of dissolved inorganic nitrogen, the results showed that the net uptake rate was 0∼60 mg/㎡/day in surface level(0∼3m), and the net regeneration rate was 0.0∼10.0 mg/㎡/day in middle level(3∼6m) and above 10mg/㎡/day in bottom level(6m∼below). In the case of dissolved inorganic phosphorus, the net uptake rate was 0.0∼3.0 mg/㎡/day in surface level, and the net regeneration rate was 0.5∼1.5 mg/㎡/day in middle level and 1.0∼3.0 mg/㎡/day in bottom level. These results indicates that net uptake and transport of nutrients are occurred predominantly at the surface level and the net generation and accumulation are dominant at bottom level. Therefore, it is important to consider the re-supplement of nutrients due to regeneration of bottom water.

• 대한건축학회논문집:계획계
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• 제34권6호
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• pp.127-134
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• 2018

The purpose of this study is to derive a model of urban regeneration business using idle facilities in the old city center. The scope of the study was set as empty houses and empty stores owned by private companies, and analyzed the 50 central city revitalization projects using idle facilities in 14 local cities in Japan. The results of this study are follows; First, as an urban regeneration strategy using idle facilities in the old town, it was a combination of other functions centering on commercial functions or introducing new functions required in the city center. Second, various financial supports have been provided to induce the utilization of idle facilities by the private sector, and different strategies have been implemented for businesses that need maintenance first. Third, based on the analysis results, it was possible to derive urban regeneration business model. Fourth, in order to operate smooth business, it is a need for an organization that is in charge of reviewing the consistency of upper-level planning and urban guiding functions such as urban revitalization plan, balance review of expenditure and revenues by cost subsidy and loan repayment, consultation among the business partners.

• 한국자동차공학회논문집
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• 제22권2호
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• pp.60-66
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• 2014

A control oriented model of the Lean $NO_x$ trap (LNT) was developed to determine the timing of $NO_x$ regeneration. The LNT model consists of $NO_x$ storage and reduction model. Once $NO_x$ is stored ($NO_x$ storage model), at the right timing $NO_x$ should be released and then reduced ($NO_x$ reduction model) with reductants on the catalyst active sites, called regeneration. The $NO_x$ storage model simulates the degree of stored $NO_x$ in the LNT. It is structured by an instantaneous $NO_x$ storage efficiency and the $NO_x$ storage capacity model. The $NO_x$ storge capacity model was modeled to have a Gaussian distribution with a function of exhaust gas temperature. $NO_x$ release and reduction reactions for the $NO_x$ reduction model were modeled as Arrhenius equations. The parameter identification was optimally performed by the data of the bench flow reactor test results at space velocity 50,000/hr, 80,000/hr, and temperature of $250-500^{\circ}C$. The LNT model state, storage fraction indicates the degree of stored $NO_x$ in the LNT and thus, the timing of the regeneration can be determined based on it. For practical purpose, this model will be verified more completely by engine test data which simulate the NEDC transient mode.

• 한국자동차공학회논문집
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• 제17권2호
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• pp.57-66
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• 2009

In this paper, the steering characteristics of tracked vehicles are studied for the improvement of steering performance. The important design factor of military vehicles is high mobility. It is influenced by weight of a vehicle, engine capacity, power-train, and steering system. The military vehicle, which is equipped with caterpillar, has unique steering characteristics and is quite different from that of a wheeled vehicle. The steering of tracked vehicles is operated in the power pack due to different speeds of both sprockets. Under cornering conditions, power split and power regeneration are happened in the power pack. In case of power regeneration, power is transferred outside track after adding engine power and power inputted inside track from the ground. However, excessive power regeneration is transferred in the power pack. It damages mechanical elements. Therefore, it is necessary to analyze the steering system and check mentioned problem above. In this study, the detailed dynamic model of steering system is presented, which includes slippage between track and roadwheel, inertia force, and inertia moment. Finally, our model is compared with the Kitano model and we verified the validity of the model.

• 디지털융복합연구
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• 제11권9호
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• pp.365-370
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• 2013

Image J 프로그램은 digital image 분석 또는 생명 공학적 분석에 사용되고 있다. 다양한 동물실험 중에서도 마우스 두개골 결손모델(Mouse calvarial defected model)은 조직공학자들에게 대표적으로 사용되고 있는 뼈의 결손모델이다. 이러한 마우스 두개골 결손 모델은 뼈의 재생 또는 새로운 지지체(scaffold)의 재생효과 실험에 사용되고 있다. 마우스 두개골에 지름 4mm의 원형 결손을 만들어 각종 실험재료를 처리하여 파괴된 마우스 두개골 뼈의 재생에 관련하여 측정하는 실험이 주를 이룬다. 실험 후에 마우스를 희생하여 대부분 헤마톡실린과 에오신 염색을 통하여 분석을 하게 된다. 다른 한편으로는 마이크로 시티(u-CT)를 사용하여 정량적인 분석을 한다. 하지만 이는 시간이 오래 걸리고 고가의 비용이 드는 단점이 있다. 이번 실험은 마우스 두개골 결손 모델 시에 프리쉐어 프로그램인 Image J를 통하여 간단하게 마우스 두개골 결손 뼈의 재생량을 2D X-ray 상으로 농도를 측정하여 정량적인 분석을 실행하였다. 결론적으로 Image J를 사용한 농도 분석법은 빠르고 정확하게 뼈의 재생량을 상대적으로 비교함으로써 신생 뼈의 관한 재생 실험자에게 도움을 줄 수 있을 것으로 사료된다.

• Journal of Periodontal and Implant Science
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• 제42권1호
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• pp.25-29
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• 2012

Purpose: There has been no attempt to establish an objective implant surgical evaluation protocol to assess residents' surgical competence and improve their surgical outcomes. The present study presents a newly developed assessment and rating system and simulation model that can assist the teaching staffs to evaluate the surgical events and surgical skills of residents objectively. Methods: Articles published in peer-reviewed English journals were selected using several scientific databases and subsequently reviewed regarding surgical competence and assessment tools. Particularly, medical journals reporting rating and evaluation protocols for various types of medical surgeries were thoroughly analyzed. Based on these studies, an implant surgical technique assessment and rating system (iSTAR) has been developed. Also, a specialized dental typodont was developed for the valid and reliable assessment of surgery. Results: The iSTAR consists of two parts including surgical information and task-specific checklists. Specialized simulation model was subsequently produced and can be used in combination with iSTAR. Conclusions: The assessment and rating system provided may serve as a reference guide for teaching staffs to evaluate the residents' implant surgical techniques.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권6호
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• pp.373-387
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• 2017

Objectives: The purpose of this study was to introduce our three experiments on bone morphogenetic protein (BMP) and its carriers performed using the critical sized segmental defect (CSD) model in rat fibula and to investigate development of animal models and carriers for more effective bone regeneration. Materials and Methods: For the experiments, 14, 16, and 24 rats with CSDs on both fibulae were used in Experiments 1, 2, and 3, respectively. BMP-2 with absorbable collagen sponge (ACS) (Experiments 1 and 2), autoclaved autogenous bone (AAB) and fibrin glue (FG) (Experiment 3), and xenogenic bone (Experiment 2) were used in the experimental groups. Radiographic and histomorphological evaluations were performed during the follow-up period of each experiment. Results: Significant new bone formation was commonly observed in all experimental groups using BMP-2 compared to control and xenograft (porcine bone) groups. Although there was some difference based on BMP carrier, regenerated bone volume was typically reduced by remodeling after initially forming excessive bone. Conclusion: BMP-2 demonstrates excellent ability for bone regeneration because of its osteoinductivity, but efficacy can be significantly different depending on its delivery system. ACS and FG showed relatively good bone regeneration capacity, satisfying the essential conditions of localization and release-control when used as BMP carriers. AAB could not provide release-control as a BMP carrier, but its space-maintenance role was remarkable. Carriers and scaffolds that can provide sufficient support to the BMP/carrier complex are necessary for large bone defects, and AAB is thought to be able to act as an effective scaffold. The CSD model of rat fibula is simple and useful for initial estimate of bone regeneration by agents including BMPs.

• KIEAE Journal
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• 제15권3호
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• pp.83-92
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• 2015

Purpose: The purpose of this study is to propose a methodology for the urban regeneration by constructing contemporary publicness. Beginning with researching on the theoretical fundamentals about publicness and urban regeneration, it introduces the examples to analyze the spatial characteristics of publicness in the contemporary urban architecture, and finally simulates a model for the formation of space through a real work. Method: The study is partially based on the Executive Urban Project, 'Masterplan to make New Taekrigi : Gosan', which was planned in 2013 to suggest a strategic settlement layout for urban regeneration. Making architectural ideas permeated into the model of urban planing, throughout the design process of initially pursued concepts to the design development stage, we could encounter a new type of formation of urban space, coinciding with the historical, cultural ecological contexts. Result: The expected result of the study intends to enhance the relationship between the formation of public space and urban structure, also ultimately to produce a urban system as 'space generator' to fulfill the social needs and its requirements.