• Title/Summary/Keyword: GMD

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The relationship between condyle position, morphology and chin deviation in skeletal Class III patients with facial asymmetry using cone-beam CT (안면비대칭을 동반한 골격성 III급 부정교합자에서 하악 과두의, 위치 형태와 이부 편위의 관계: cone-beam CT를 이용한 연구)

  • Lee, Bo-Ram;Kang, Dae-Keun;Son, Woo-Sung;Park, Soo-Byung;Kim, Seong-Sik;Kim, Yong-Il;Lee, Kyung-Min
    • The korean journal of orthodontics
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    • v.41 no.2
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    • pp.87-97
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    • 2011
  • Objective: Facial asymmetry is usually evaluated from the difference in length and angulation of the maxilla and mandible. However, asymmetric position or shape of the condyle can also affect the expression of asymmetry. The purpose of this study was to evaluate the correlation between condylar asymmetry and chin point deviation in facial asymmetry. Methods: Cone-beam CT images of fifty adult skeletal Class III patients were studied. Thirty patients who had more than 4 mm menton deviation were categorized in the asymmetric group. Twenty patients with less than 4 mm menton deviation were assigned to the symmetric group. Anteroposterior and transverse condyle positions were evaluated from the cranial base. The greatest mediolateral diameter (GMD) of the condyle in the axial plane and angulation to the coronal plane were measured. The height and volume of the condyles were evaluated. Results: The symmetric group had no statistical difference between both condyles in position, angulation, GMD, height and volume. In the asymmetric group, the non-deviated side condyle was larger in GMD, height and volume than the deviated side. There was no statistical difference in condyle position and angulation. The GMD, height difference and condylar volume ratio (non-deviated/deviated) were positively correlated with chin deviation. From the linear regression analysis, condylar volume ratio was a significant factor affecting chin deviation. Conclusions: These findings suggests that the non-deviated side condyle is larger than the deviated side. In addition, condylar asymmetry can affect the expression of facial asymmetry.

Particle Size Analysis of Lead Aerosol with the use of 2730ppm Lead Nebulizing Solution for Inhalation Toxicology Study (흡입독성 연구를 위한 2730ppm 납 네뷸라이징 용액에서 발생된 에어로졸의 입경분석)

  • Jeung Jae Yeal;Kang Sung Ho;Kim Sam Tae;Lee Eun Kyoung;Song Young Sun;Lee Ki Nam
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.2
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    • pp.518-524
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    • 2003
  • Ultrasonic nebulizer with the application of new engineering methodology and the design of electronic circuit was made for lead inhalation toxicology study and 2730ppm lead nebulizing solution was used to generate lead aerosol. After modification of source and inlet temperatures, the results of particle size analysis for lead aerosol were as following. The highest particle counting for source temperature 20℃ was 39933.66 in inlet temperature 100℃ and particle diameter 0.75tLm. The highest particle counting for source temperature 50℃ was 39992.71 in inlet temperature 250℃ and particle diameter 0.75μm. The highest particle counting for source temperature 70℃ was 37569.55 in inlet temperature 50℃ and particle diameter 0.75μm. The ranges of geometric mean diameter(GMD) were 0.754-0.784μm for source temperature 2℃, 0.758-0.852μm for source temperature 50℃, and 0.869-1.060μm for source temperature 70℃. The smallest GMD was 0.754μm in source temperature 20℃ and inlet temperature 20℃, and the largest GMD was 1.060μm in source temperature 70℃ and inlet temperature 250℃. The ranges of geometric standard deviation(GSD) were 1.730-1.782 for source temperature 20℃, 1.734-1.894 for source temperature 50℃, and 1.921-2.148 for source temperature 70℃. The lowest GSD was 1.730 in source temperature 20℃ and inlet temperature 20℃, and the highest GSD was 2.148 in source temperature 70℃ and inlet temperature 250℃. Lead aerosol generated in this study was polydisperse. The ranges of mass median diameter(MMD) were 1.856-2.133μm for source temperature 20℃, 1.877-2.894μm for source temperature 50℃, and 3.120-6.109μm for source temperature 70℃. The smallest MMD was 1.856μm in source temperature 20℃ and inlet temperature 20℃, and the largest MMD was 6.109μm in source temperature 70℃ and inlet temperature 250℃. Slight increases for GMD, GSD, and MMD values were observed with same source temperature and increase of inlet temperature. MMD for inhalation toxicology testing in EPA guidance is less than 4μm. In this study, source temperature 20℃ and 50℃ with inlet temperature from 20℃ to 250℃ were conformed to the EPA guidance, but inlet temperature 20℃ and 50℃ for source temperature 70℃ were conformed EPA guidance. MMD for inhalation toxicology testing in OECD and EU is less than 3μm. In this study, source temperature 20℃ and 50℃ with inlet temperature from 20℃ to 250℃ were conformed to the EPA guidance, but none for source temperature 70℃.

Study on the Fine Particle Charging Characteristics with the Electrohydrodynamic Atomization (전기 수력학적 방법을 이용한 미세 입자의 하전 특성에 관한연구)

  • 안진홍;김광영;윤진욱;안강호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.4
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    • pp.289-294
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    • 2001
  • A well defined electro-spraying and electro-static precipitator(ESP) experiment is carried out to investigate the charging characteristics of the submicron particles and the monodisperse particles. The basic idea is that the highly charged electro-sprayed droplets will be produced into the gas when the Coulombic repulsive force on the surface is higher than the surface tension of the spraying liquid. During this process many highly charged smaller droplets or ions, if the droplets are completely dried out, will be produced in the space. These charged species will be attached ion the particles and then eventually charge the particles. These charged particles will be easily collected with ESP. The experimental results show that the atomizer generated particles with geometric mean diameter (GMD) of 62nm are charged more than 90% even at the mean face velocity of 2.5m/s at the charging zone.

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An Experimental Study on the Characteristics of Generated Particle using Homogeneous Condensation Particle Generator (응축입자 발생기에서의 입자 발생특성에 관한 실험적 연구)

  • Kim, J.H.;Kim, S.S.
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.392-397
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    • 2000
  • Mono-disperse particles generated by a condensation particle generator are widely used to meet the experimental and industrial needs. The characteristics of particles generated by homogeneous nucleation have been studied experimentally using a laminar flow condensation particle generator. Dry nitrogen gas saturated with oleic acid vapor was cooled well below the saturation temperature causing the highly supersaturated vapor to nucleate. The dependence of GSD(Geometric Standard Deviation), GMD(Geometric Mean Diameter), and the mass concentration of particles on the temperature at the evaporator, flow rate and the temperature condition at condenser was studied. The experimental results show that the mass concentration of particles is affected by the radial temperature profile at condenser. Nucleation at the center of the condenser causes the mass concentration of particles to increase. The experimental results also show that the suppression of additional nucleation by a constant temperature condition at the condenser increases the mean diameter of particle.

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A Study on the Inductance computation of a Superconducting Power cable (초전도 전력케이블의 인덕턴스 산정에 관한 연구)

  • Choi, S.J.;Song, M.K.;Lee, S.J.;Sim, K.D.;Cho, J.W.
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1243-1245
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    • 2005
  • 신뢰성 있는 초전도전력 케이블의 설계를 위하여 초전도 케이블 각층의 인덕턴스 산정방법을 기존 방법과 새로 제안된 방법을 비교하였으며, 새로 제안된 방법에 의한 인덕턴스 계산을 검증하기 위하여 상용전자장해석 프로그램을 이용하여 그 계산결과를 비교하였다. 기존의 초전도 전력케이블의 인덕턴스 산정방식인 Go and Return Method 및 Energy Method에 대한 전자기적 타당성을 재검토하였으며, 더 나아가 Newman Method와 Geometric Mean Distance를 결합한 Neumann-GMD Method를 제안하였다. 각 방법의 신뢰성 검증을 위하여 상업적으로 검증된 전자장 해석 tool인 OPERA를 이용하여 특정 피치에 대한 2층 구조의 케이블을 모델링하고 그 인덕턴스를 계산하여, 각 방법에 의하여 계산된 인덕턴스 값과 비교하였다. 이 과정을 통하여 가장 신뢰성 있는 인덕턴스 계산법을 선택하여 초전도 전력 케이블의 설계에 적용하고자 한다.

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A Study on the Comparison of Applying RDA in US Academic Libraries (미국 대학도서관의 RDA 적용에 관한 비교 연구)

  • Lee, Mihwa
    • Journal of the Korean Society for information Management
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    • v.31 no.1
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    • pp.77-97
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    • 2014
  • It is necessary to find the practical considerations for applying RDA in building up the bibliographic records by importing RDA records from LC or OCLC in Korea. Especially, it is not easy to apply RDA appropriately because there are many alternatives and options in RDA. Therefore, this study is to grasp the way for applying RDA in building up the bibliographic records by reviewing LC RDA guidelines and analyzing RDA cataloging policies of libraries such as University of Chicago, North Carolina State University, and Standford University. As a result, these libraries have catalogued according to LC RDA guidelines and each library has its own guidelines, i.e., in statement of responsibilities, to transcribe all but exceptionally allow to transcribe only first, in publication statement, to use 264 field or 260 field, and in resource types, to transcribe all types of content, media and carrier or to transcribe 33X with GMD. Therefore followings would be considered for RDA application. First, some variations could be allowed for special situations of libraries in applying RDA and LC RDA guidelines. Second, the hybrid records that describe the core element of RDA to non-RDA records would be written in processing AACR2 to RDA. Third;the display of 33X field would be designed for expressing the resource types.

A Study on Consideration in KCR4 through Testing the Description of Content Types and Media Types of ISBD and RDA (ISBD 및 RDA 내용유형 및 매체유형 기술 테스트를 통한 KCR4의 고려사항에 관한 연구)

  • Lee, Mihwa
    • Journal of the Korean Society for Library and Information Science
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    • v.47 no.3
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    • pp.119-137
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    • 2013
  • This study was to compare the description of content types(content forms) and media types of RDA and ISBD in order to revise GMD of KCR4. Test and survey were conducted as the research methods for comparing content types and media types description of RDA and ISBD. As a result, RDA content types description is better than ISBD in aspects of uniformity and correct rates. Especially, detailed list of content types in RDA could make the resources to be expressed completely, but content forms with adding the content qualification in ISBD could make the resource to be expressed with many errors. Therefore, there were some considerations to describe content types. First, content types terms in RDA need to be specified more. Second, some detailed rules need to be regulated on the combination of content qualification of ISBD. Third, the mapping tables between RDA content types and ISBD content forms need to be revised. Fourth, RDA content types list will be more applicable in KCR4 based on the uniformity and correct rates in the test. This study will contribute to analyze and suggest RDA and ISBD terms list of content types and media types for KCR4.

A Study on the Display Considerations of RDA Resource Type (RDA 자원유형 디스플레이를 위한 고려사항에 관한 연구)

  • Lee, Mihwa
    • Journal of the Korean Society for information Management
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    • v.33 no.1
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    • pp.33-52
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    • 2016
  • This study was to find the display considerations of RDA resource type - content type, media type, and carrier type. The Literature review, the case study, and the survey were used as the research method. 5 display strategies were suggested in this study. First, content and carrier types were better displayed than all 3 types of RDA resources. Second, two kinds of algorithm should be considered for RDA resource icon display. One was the combination of the terms of carrier types plus content types icon. The other was the combination of carrier types icon and content types icon in which the terms reflecting types must be included. Third, the subfield of 33x must be used for the paired display of content type and carrier type of multi-types resources. Fourth, in brief display, resource type icon was better positioned on the left and upper side and in detailed display, resource types were better located in description area. Fifth, 'format' was used as display indication phrase. This study would contribute to the design for the resource display by suggesting the practical display considerations of RDA resource type.

Analysis of the Effect of Particle Size and Humidity on Reaction Characteristics of $CaCO_3$ Sorbent Particle under Air and $O_2/CO_2$ Atmospheric Conditions (공기연소 분위기와 순산소 연소 분위기에서 입자 크기와 습도가 $CaCO_3$ 흡착제 입자의 반응특성에 미치는 영향 분석)

  • Jeong, Seongha;Lee, Kang Soo;Keel, Sangin;Yun, Jin Han;Kim, Sang Soo
    • Particle and aerosol research
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    • v.10 no.2
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    • pp.75-82
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    • 2014
  • It is necessary to find out the reaction characteristics of $CaCO_3$ sorbent particles in air and $O_2/CO_2$ atmospheric conditions in order that an in-furnace desulfurization technique can be applied to oxy-fuel combustion system. In this study, rate of change of GMD(geometric mean diameter) and specific surface area of $CaCO_3$ sorbent particles reacted in DTF(drop tube furnace) experimental setup were analyzed to investigate the effect of particle size and humidity on the reaction characteristics of them. In air atmospheric condition, calcination process occurs actively within shorter residence times as the particle size increases. On the contrary, in $O_2/CO_2$ atmospheric condition, a calcination process is delayed as particle size increases. The increment of humidity accelerates calcination process in an air atmospheric condition and increase rate of calcination in an $O_2/CO_2$ atmospheric condition.

Evaluation on the Physical and Chemical Properties of Expanded Rice Hulls as Hydroponic Culture Medium (양액재배용 팽연화 왕겨 배지의 이화학적 특성 구명)

  • 김경희;임상현;남궁양일;유근창
    • Journal of Bio-Environment Control
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    • v.9 no.2
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    • pp.73-78
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    • 2000
  • This study was carried out to investigate appropriate processing conditions for expanded rice hulls to be used as a medium material in nutrient cultures. The water holding capacity of expanded rice hulls produced by using a domestic grinder with 8 mm gap and 3 mm cutter height was 271.0, and the bulk density and CEC were 0.19g·m-3 and 37.0 cmol·kg-1, respectively. These values are higher than those of perilte. However, geometric mean diameter (GMD) of expanded rice hulls was 1.01mm which was smaller than that of perlite, indicating unfavorable porosity. After supplying nutrient solution, the faster water percolation in expanded rice than perlite required more frequent water supply. There was no significant difference in tomato fruit yield between expanded rice hull and perlite. The pH increase and the lack of nitrogen in early stage of culture are to be solved in the future.

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