• 제목/요약/키워드: filling factor

검색결과 220건 처리시간 0.03초

초등학생의 Dental IQ 수준과 구강보건 관리실태 (Dental IQ and Oral Health Care Status of Elementary School Students)

  • 김광덕;전진호
    • 보건교육건강증진학회지
    • /
    • 제20권2호
    • /
    • pp.95-112
    • /
    • 2003
  • Objectives: Oral health care program for the elementary school children (ESOHCP) should be met the first priority because dental caries are highly sensitive and prevalent among them. This study was performed to enhance the efficiency of ESOHCP, and their oral health promotion. Methods: The Subjects were 346 students (3rd grade 163, 6th grade 185) of one elementary school in Busan. Dental IQ and actual oral health status; the decayed, mixing and filling teeth were checked through questionnaire and oral health examination from April to June 2002. Dental IQ was presented out of one hundred, and data analysis was done using SAS (ver 8.1) program. Results: The students' cognitive level about the causative and preventive factor of dental caries was relatively high. However, the practical aspects of preventive behavior - tooth brushing; three times per day (20%), three minutes per time (22%), oral health examination; one time per three months (10%) left much to be desired. And, only 27% of the subjects had experienced in school oral health education. The mean level of dental IQ was 79 out of 100, and 51 % and 42% of them had the decayed and teeth with filling, respectively, with the rate of DMFT 82%, DT 43%, FT 57%. The level of dental IQ was higher in case of having his (her) own tooth brush (p=0.072), standard tooth brushing (p<0.001) three times per day, post meal, three minutes per time, present experience of oral health examination (p<0.001) and dental clinic visit (p<0.001). The grade of caries was more serious in case of 6th grade (p=0.059), an absence of his (her) own tooth brush (p= 0.090), present experience of oral health examination (p=0.021), and an absence of regular dental clinic visit (p=0.003). The frequency of oral health examination (γ= 0.620), tooth brushing; times per day (γ=0.445), post meal (γ=0.355), expending times per brushing (γ=0.352), right cognition to the treatment of caries (γ=0.401), positive attitude to dental treatment (γ=0.387), the frequency of dental clinic visit for the past one year (γ=0.152) showed significant correlation with dental IQ. In the multivariate analysis, dental IQ was influenced by the frequency of oral health examination, right cognition to the cause of caries, times of teeth brushing per day, right cognition to the treatment of caries, etc., with adjusted R2=0.857. Conclusion: Though the students' cognitive level about the causative and preventive factor of dental caries was high, the practical aspects of preventive behavior left much to be desired. Ant the current ESOHCP considered to be still inefficient. However, frequent dental visits had apparent correlation with hish level of dental IQ. The specialized and practical program should be needed for the efficient ESOHCP. Harmonized effort from educational, health and dental society is essential.

콘크리트 충전 브릿지 플레이트(대골형 파형강판) 부재의 성능평가 (Performance Evaluation of Encased-Concrete Bridge Plate(Deep Corrugated Steel Plate) Member)

  • 심종성;박철우;김태수;이형호;강태성
    • 콘크리트학회논문집
    • /
    • 제22권3호
    • /
    • pp.297-303
    • /
    • 2010
  • 현재 개발된 콘크리트 충전 대골형 파형 강판은 아치형 플레이트의 구조로서 그 특징은 구조물이 아치의 형상을 가지므로 모멘트가 작게 발생하는 압축력 지배구조의 구조적 특성을 가지게 되며 이에 따라 강재를 덧대 준공된 공간을 압축력에 유리한 콘크리트를 충전 강재 콘크리트 합성단면을 형성하여 압축력에 대한 강도 발현증대를 목적으로 한다. 이 연구에서는 새로운 개념의 콘크리트 충전 대골형 파형강판(브릿지 플레이트) 부재의 압축 및 휨 시험을 실시하여 평가된 압축력과 콘크리트 충전 브릿지 플레이트 구조물의 설계방법인 캐나다 도로교설계기준(CHBDC)의 방법으로 설계압축력을 산정하여 비교 검토함으로서 새로운 개념의 콘크리트 충전 브릿지 플레이트 부재의 안전율을 평가하였다. 설계압축력과 성능평가 시험을 통하여 얻어진 축력을 비교하여 안전율을 검토한 결과 적정 안전율 2.0이상 과도하게 나타나 CHCBD을 이용한 설계가 매우 보수적으로 평가되고 있으며, 이 연구 결과를 바탕으로 안전율을 설계에 반영한다면, 단면축소 및 시공비용 절감에 따른 경제적인 시공이 가능할 것으로 판단된다.

핫엠보싱 공정의 폴리머 점탄성 거동에 대한 연구 (Experimental and numerical study on viscoelastic behavior of polymer during hot embossing process)

  • 송남호;손지원;임성한;오수익
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2007년도 춘계학술대회 논문집
    • /
    • pp.191-194
    • /
    • 2007
  • In hot embossing lithography which has shown to be a good method to fabricate polymeric patterns for IT and bio components, it is very important to determine the proper process conditions of pressure, temperature, and time. It is also a key factor for predicting the optical properties of final product to calculate residual stress distribution after the embossing process. Therefore, to design the optimum process with right conditions, the ability to predict viscoelastic behavior of polymer during and after the hot embossing process is required. The objective of the present investigation is to establish simulation technique based on constitutive modeling of polymer with experiments. To analyze deformation behavior of viscoelastic polymer, the large strain material properties were obtained from quasi-static compression tests at different strain rates and temperatures and also stress relaxation tests were executed. With this viscoelastic material model, finite element simulation of hot embossing was executed and stress distribution is obtained. Proper process pressure is very important to predict the defect and incomplete filling.

  • PDF

A Study on Smoke Movement in Room Fires with Various Pool Fire Location

  • Jeong, Jin-Yong;Ryou, Hong-Sun
    • Journal of Mechanical Science and Technology
    • /
    • 제16권11호
    • /
    • pp.1485-1496
    • /
    • 2002
  • In order to investigate the fire-induced smoke movement in a three-dimensional room with an open door, numerical and experimental study was performed. The center, wall, and corner fire plumes for various sized fires were studied experimentally in a rectangular pool fire using methanol as a fuel. The numerical results from a self-developed SMEP (Smoke Movement Estimating Program) field model were compared with experimental results obtained in this and from literature. Comparisons of SMEP and experimental results have shown reasonable agreement. As the fire strength became larger for the center fires, the air mass flow rate in the door, average hot layer temperature, flame angle and mean flame height were observed to increase but the doorway-neutral-planeheight and the steady-state time were observed to decrease. Also as the wall effect became larger in room fires, the hot layer temperature, mean flame height, doorway-neutral-planeheight and steady-state time were observed to increase. In the egress point of view considering the smoke filling time and the early spread of plume in the room space, the results of the center fire appeared to be more dangerous as compared with the wall and the corner fire. Thus it is necessary to consider the wall effect as an important factor in designing efficient fire protection systems.

사출압력 최소화와 웰드라인 방지를 위한 자동차용 사출성형 부품의 최적설계 (Design Optimization of an Automotive Injection Molded Part for Minimizing Injection Pressure and Preventing Weldlines)

  • 박창현;표병기;최동훈;구만서
    • 한국자동차공학회논문집
    • /
    • 제19권1호
    • /
    • pp.66-72
    • /
    • 2011
  • Injection pressure is an important factor in filling procedure for injection molded parts. In addition, weldlines should be avoided to successfully produce injection molded parts. In this study, we optimally obtained injection molding process parameters that minimize injection pressure. Then, we determined the thickness of the part to avoid weldlines. To solve the optimization problem proposed, we employed MAPS-3D (Mold Analysis and Plastics Solution-3 Dimension), a commercial CAE tool for injection molding analysis, and PIAnO (Process Integration, Automation, and Optimization) as a commercial PIDO (Process Integration and Design Optimization) tool. We integrated MAPS-3D into PIAnO, automated the analysis and design procedure, and performed optimization by employing PQRSM (Progressive Quadratic Response Surface Method) equipped in PIAnO. We successfully obtained optimization results, which demonstrates the effectiveness of our design method.

원호필렛-인벌류트 스퍼어 기어의 밀폐단조에 관한 상계해석 (An Upper-Bound Analysis for Closed-Die Forging of the Involute Spur Gears with Circular Arc Fillet)

  • 최재찬;허관도;김창호;최영
    • 소성∙가공
    • /
    • 제3권1호
    • /
    • pp.97-109
    • /
    • 1994
  • Closed-die forging of the spur gears with circular are fillet has been analyses by using the upper-bound method. A kinematically admissible velocity field has been developed, wherein, the tooth profile consists of the involute curve and the circular arc fillet. In the analysis, the deformation regions have been divided into eight zones. A constant frictional stress has been assumed on the contacting surfaces Utilizing the formulated velocity field, numerical calculations have been carried out to investigate the effects of various parameters, such as module, number of teeth, addendum modification coefficient and friction factor, on the relative forging pressure of spur gears. As the result of numerical calculations, the relative forging pressure does not change so much against the variation of module. On the other hand, the relative forging pressure increases at the final filling stage as the addendum modification coefficient increases.

  • PDF

흡착질의 증기압이 흡착에 미치는 영향 (Effect of Vapor Pressure of Adsorbate on Adsorption Phenomena)

  • 김상원;권준호;강정화;송승구
    • 한국환경과학회지
    • /
    • 제17권1호
    • /
    • pp.67-75
    • /
    • 2008
  • Adsorption process is largely influenced by pore structures of adsorbents and physical properties of adsorbates and adsorbents. The previous studies of this laboratory was focused on the role of pore structures of adsorbents. And we found some pores of adsorbates which have larger pore diameters than the diameter of adsorbate are filled with easily. In this study the effects of physical and chemical properties of adsorbates and adsorbents, such as pore size distribution, vapor pressure on adsorption were investigated more thoroughly at the concentration of adsorbate of 1000 ppm. The adsorption in the pore ranges of $2{\sim}4$ times of adsorbates's diameter could be explained by space filling concept. But there was some condensation phenomena at larger pore ranges. The errors between the adsorbed amount of non-polar adsorbates and the calculated amounts by considering factors were found to be 44.46%, positively, and -142%, negatively. When vapor pressure is considered, the errors between the adsorbed amount of non-polar adsorbates and the calculated amounts were in the range of $1.69%{\sim}32.25%$ positively, and negatively $-1.08%{\sim}-63.10%$.

'Viewpoints/ Concerns' on empirical methodologies for Socio/ cultural studies

  • Ashis, Jalote Parmar;Lee, Kun-Pyo
    • 한국디자인학회:학술대회논문집
    • /
    • 한국디자인학회 2004년도 추계 학술발표대회 논문집
    • /
    • pp.212-213
    • /
    • 2004
  • Since the advent of man there has been a constant struggle to define social pattern, and understand ways of cultural thinking. Every culture has it's own limitations and freedoms, problems and expectations. For centuries now anthropologist, ethnographers have worked on mapping and defining these differences. These findings instigate the designers to formulate new design theories and research methodologies for drafting cultural specific solutions. The question arises 'in a cross cultural application how effective and applicable are the basic research methodologies'? Quoting one such example the 'Privacy' issue seems to be a very strong component in the Japanese culture but is often a deterring factor in allowing the 'home ethnographic study to take place effectively'. However in countries like India similar studies could have a more welcoming reaction owing to the adaptive social culture. Similarly, the high rate of 'Illiteracy' in rural India closes many doors for 'form filling' user surveys. This leads to the scope of research for understanding specific cultural traits that may effect adaptation and re-improvisation of these existing methodologies. Quite often the cultural traits of a country may lead in forming new research methodologies.

  • PDF

핵자기공명 영상법을 위한 내부 영상용 뒤집음-탐침의 제작 (Construction of Magnetic Resonance Imaging Inside-out probes for Internal Imaging)

  • 고락길;이동훈;정은기
    • 대한의용생체공학회:학술대회논문집
    • /
    • 대한의용생체공학회 1995년도 추계학술대회
    • /
    • pp.78-81
    • /
    • 1995
  • In imaging the samples or human internal organs in a tube shape, general RF-probe types (that encircles a sample or places on top of the sample) are usually unsuitable for the internal imaging due to the degradation of signal-to-noise ratios(SNR's). In the present study the inside-out probes for Magnetic Resonance Imaging (MRI) have been constructed in the three different shapes such as an anti-solenoidal, a saddle and a dual surface types which are positioned as close to the area as possible by putting the probe inside the tubelike sample to improve filling factor. RF-field distributions have also been calculated depending upon the geometrical changes of anti-solenoid probes. Moreover, the performance of the inside-out probes has been checked by measuring SNR's of the images acquired. The inside-out probes constructed in this study produced better SNR's and rf-field uniformity in the area close to the probes in comparing with any other commercial probes. There is a high possibility that the constructed probes in the present study are applicable to the diagnosis of human bodies.

  • PDF

Effects of Advertising Campaign on the Salesperson's Performance: Should a Multilevel Marketing Firm Advertise Its Brand to Customers?

  • YOO, Changjo;CHO, Yooncheong
    • 산경연구논집
    • /
    • 제10권6호
    • /
    • pp.7-17
    • /
    • 2019
  • Purpose - The purpose of this study is to explore how advertising for multilevel marketing brands affect the salesperson's activity including customer-salesperson interactivity, work attitude, and perceived and actual performance after the campaign. Research Design, data, and methodology - This study collects experimental data, survey data, and actual sales data and applies statistical analyses such as factor analysis, t-tests, and a structural equation model. Results - The results show that advertising campaign can enhance a salesperson's selling activities and provide wide managerial implications to a multilevel marketing firm by filling the gaps for the field of advertising research. Conclusions - Managerial implications include: i) multilevel marketing firms should consider advertising campaigns as a means of changing customer responses because advertising plays a significant role in increasing familiarity with, and knowledge of, attitudes toward the brand, which also helps salespeople interact with customers; ii) multilevel marketing firms should consider brand advertising as a means to support the sales activities of salespeople including sales effectiveness, work attitudes, and perceived performance, and iii) multilevel marketing firms should consider brand advertising as a means to enhance a salesperson's pride and motivation for selling their brand, which will lead to improved sales performances.