INTRODUCTION OF SPARK EROSION

정창모,Jeong, Chang-Mo 대한치과보철학회 2000 대한치과보철학회지 Vol.38 No.4

The dental profession is currently experiencing a technology explosion. Processes are being replaced by modern, inexpensive, and precise techniques that can be used to solve complex restorative problems. Electrical discharge machining(EDM, known as spark erosion in Europe) is a nonconventional, industrial technique that has application in dentistry. EDM may be defined as a metal removal process using a series of sparks to erode material from a workpiece in a liquid medium under carefully controlled conditions. EDM is recently adopted in the dental laboratory to fabricate precision attachments, hybrid tele-scope crowns, Ti-ceramic crowns. EDM has also been used to achieve a passive precision metal-to-metal fit between the substructure bar and the removable superstructure and to correct the fit of implant retained restorations. In this article, a brief history and explanation of EDM is discussed and a description of the use of this process for fabricating attachments and crowns or for correcting the fit of cast restorations is presented.

수종의 상악 총의치수지상 금속보강법에 관한 비교연구

정창모,Jeong, Chang-Mo 대한치과보철학회 1996 대한치과보철학회지 Vol.34 No.2

A common site of fracture in maxillary complete denture is on the anteroposterior midline that coincides with the notch for relief of the labial frenum. Various approaches to reduce the incidence of this type of fracture have been suggested. The most widely used technique is the reinforcement of acrylic resin denture base with several solid metal forms. But few comparative studies on the efficacy of metal reinforcements have been reported. This study was conducted to compare reinforcing effects of commonly available metal reinforcements, which include wire, metal mesh embedded in the denture base and metal plate affixed to the impression surface of denture base by silicoating technique. This was load on the posterior. The strain gauges were oriented perpendicular to the anteroposterior midline of maxillary polished denture surface at one labial and the four palatal sites Non-renforced denture was used as control. The results were as follows : 1. In the non-reinforced denture group, only tensile strains on the palatal polished surface were observed. The tensile strains decreased in the order of incisive papilla, posterior denture border area, mid palatal area and rugae area. Compressive strain was observed on the labial polished surface. 2. As compared with the non-reinforced denture group, the metal plate or the metal mesh reinforced denture groups showed reduced palatal tensile strains,and the metal mesh reinforcement had a better reinforcing effect than the metal plate. But both reinforced denture groups showed no difference in the amount of compressive strain on the labial polished surface when compared to the non-reinforced denture group. 3. The metal wire positioned just above the labial notch decreased the compressive strain on the labial polished surface. But the presence of metal wires in the palatal polished surface caused increase in tensile strains in the area.

현행 세법상 계산서 교부 및 보고제도의 문제점과 개선방안

鄭昌模 한국조세연구포럼 2002 조세연구 Vol.2 No.-

4차 산업시대의 데이터과학자의 직무특성과 셀프리더십이 조직효과성에 미치는 영향

정창모 한국마케팅관리학회 2020 한국마케팅관리학회 학술대회 Vol.2020 No.11

심포지엄 : 소수 잔존치 환자의 임플란트 보철치료

정창모 대한치주과학회 2007 대한치주과학회 학술대회자료집 Vol.2007 No.1

서스팬션 슈우퍼엘리먼트 기법을 이용한 자동차의 동력학적 해석

정창모,유완석 대한기계학회 1988 대한기계학회논문집 Vol.12 No.3

본 연구에서는 자동차의 동력학적 해석을 위한 특별프로그램을 만들어서 범용 프로그램인 DADS와 효율성을 비교해 보고자 한다. Dynamic analysis of a vehicle is carried out with rigid body and flexible body models. The chassis of the vehicle is treated as flexible body in the flexible body model, and vibration normal modes are considered to account for elastic deformation of the component. Using output from the modal analysis in the finite element program, input data for the dynamic analysis with flexible body is generated. To achieve the computational efficiency, SUPERELEMENT technique is used for the vehicle suspension subsisted. The computer simulation time with suspension superelement was much reduced due to the reduction of coordinates and no kinematic constraint in the system.

수종의 가열 종합방법에 따른 위치상용레진의 물리적 성질에 관한 비교연구

정창모 치과연구사 1990 치과연구 Vol.28 No.6

골유착성 임프란트와 자연치를 이용한 고정성 국소의치에서 응력분산 및 충격흡수에 관한 유한요소법적 응력분석

정창모,이호용 대한치과이식임플란트학회 1992 The Korean Academy of Implant Dentistry Vol.12 No.1

The long-term success of any dental implant is dependent upon the optimization of stresses which occur during oral function and parafunction. Especially, it has been suggested that there is an unique set of problems associated with joining an osseointegrated implant and a natural tooth with a fixed partial denture. For this particular case, although many literatures suggest different ways to avoid high stress concentrations on the bone surrounding the implant under static and dynamic loading conditions, but few studies on the biomechanical efficacy of each assertion have been reported. The purpose of this investigation was to evaluate the efficacies of clinically suggested methods on stress distribution under static load and shock absorption under dynamic load, using two dimensional finite element method. In FEM models of osseointegrated implant-natural tooth supported fixed partial dentures, calculations were made on the stresses in surrounding bone and on the deflections of abutments and superstructure, first, to compare the difference in stress distribution effects under static load by the flexure of fastening screw or prosthesis, or intramobile connector, and second, to compare the difference in the shock absorption effects under dynamic load by intramobile connector or occlusal veneering with composite resin. The results of this analysis suggest that : 1. Under static load condition, using an implant design with fastenign screw connecting implant abutment and prosthesis or increasing the flexibility of fastening screw, or increasing the flexibility of prosthesis led to the increase in height of peak stresses in cortical bone surrounding the implant, and has little effect on stress change in bone around the natural tooth. 2. Under static load condition, intramobile connector caused the substantial decrease in stress concentration in cortical bone surrounding the implant and the slight increase in stress in bone around the natural tooth. 3. Under dynamic load condition, both intramobile connector and composite resin veneering showed shock absorption effect on bone surrounding the implant and composite resin veneering had a greater shock absorption effect than intramobile connector.

총의치 제작시의 교합형성

정창모 대한치과의사협회 1999 대한치과의사협회지 Vol.37 No.11

B2B기업의 CSR명성이 영업사원의 소진(burnout)에 미치는 영향

정창모 한국콘텐츠학회 2021 한국콘텐츠학회논문지 Vol.21 No.10

Recently, the importance of B2B CSR is being highlighted. Meanwhile, in B2B marketing, salesperson is widely recognized as a key resource influencing supplier firm performance. Therefore, the author paid attention to the role of supplier CSR reputation in customer-salesperson interaction process. So, this study collected dyadic data from 161 B2B purchasing managers and salespersons interacting with them. For customers, a supplier CSR reputation increased customer citizenship behavior and customer long-term orientation. With salespersons, they experienced less burnout due to interacting with customers having higher customer citizenship behavior and long-term orientation. Moreover, the results confirmed that a supplier CSR reputation lowered salespersons’ emotional exhaustion through two serial-multiple mediation paths. This research verified that customers' perception and responses to supplier’s CSR significantly influence B2B salesperson burnout.