• 제목/요약/키워드: National measurements standards

검색결과 171건 처리시간 0.024초

Tip and taper compatibility of accessory gutta-percha points with rotary and reciprocating instruments

  • Julia Niero Zanatta Streck; Sabrina Arcaro;Renan Antonio Ceretta;Eduardo Antunes Bortoluzzi;Lucas da Fonseca Roberti Garcia;Josiane de Almeida ;Patricia Maria Poli Kopper ;Anarela Vassen Bernardi
    • Restorative Dentistry and Endodontics
    • /
    • 제48권3호
    • /
    • pp.22.1-22.8
    • /
    • 2023
  • Objectives: This study was conducted to evaluate and compare the tip and taper compatibility of accessory gutta-percha points (AGPs) with various rotary and reciprocating instruments. Materials and Methods: Using a profile analyzer, tip and taper measurements were taken of 10 AGPs of each of the 14 models available from Odous de Deus and the 4 models available from Dentsply-Maillefer. Diameter measurements were taken at 1-mm intervals, from 3 mm from the tip (D3) to 16 mm. Results: Based on the mean values obtained, 3-dimensional (3D) models of the AGPs were drawn in Autodesk Fusion 360 and superimposed on 3D models of each instrument selected (Mtwo, Reciproc, RaCe, K3, and ProDesign Logic) to determine the compatibility between the instrument and the AGP. Data corresponding to the tips and tapers of the various AGPs, as well as the tip and taper differences between the AGPs and the instruments, were analyzed using descriptive statistics. The tapers of the AGPs were subject to the American National Standards Institute/American Dental Association No. 57 standard. The Odous de Deus extra-long medium and extra-long extra-medium AGPs were shown to be compatible with Mtwo, K3, and ProDesign Logic instruments with taper 0.06 and tip sizes 25 and 30, while the Dentsply fine and fine medium cones were compatible with Mtwo, RaCe, and K3 instruments with conicity of 0.04 and tip sizes 35 and 40. Conclusions: Both the Odous de Deus and Dentsply commercial brands included 2 AGP models with tip (D3) and taper compatibility with Mtwo, RaCe, K3, and/or Prodesign Logic instruments.

어린이의 식습관(食習慣)이 체위(體位)에 미치는 영향(影響)에 관한 연구(硏究) (The Influence of Food Habits on Body Stature of Children)

  • 이미숙;모수미
    • Journal of Nutrition and Health
    • /
    • 제9권1호
    • /
    • pp.7-15
    • /
    • 1976
  • The Purpose of this study was to determine every possible correlation between food habits and body statures of primary school children, aged ten years old. This study was conducted from July to October of 1975. In July, prepared questionaires concerning life style, anthropometry, food preference, and food behavior were distributed through school teachers to 425 children; 219 boys and 206 girls, in the 5th grade of three elementary schools in the city of Seoul. Then, in October, when subjects had been classified into underweight/obese by statistical analysis, mothers of obese or underweight children were interviewed by the authors to determine weaning history, daily food consumption of their children, and opinions of various snacks for children. Analysis of results in terms of correlation coefficient, chisquare test and percentage calculations, are as follows: 1. Physical growth and development Boys Girls Height (cm) $134.8{\pm}5.74\;134.4{\pm}5.97$ Weight (kg) $30.0{\pm}4.27\;29.5{\pm}5.16$ Chestgirth (cm) $64.1{\pm}3.59\;63.3{\pm}3.81$ Arm circumference (cm) $18.3{\pm}1.61\;18.2{\pm}1.70$ Triceps skinfold thickness (mm) $10.9{\pm}5.13\;12.7{\pm}4.86$ Various indices of nutrition such as relative weight, relative chestgirth, $R{\ddot{o}}hrer's$ index, Kaup index, Vervaeck index were determined. 2. Food habits 1) Food $preference{\cdots}{\cdots}A$ varying number of foods were selected from 60 items were accepted. It was found that the food which children liked best was fruit and snacks were popular one. Lowest ranking among LIKED foods were from strongly flavored vegetables and organ meat. In general, girls had more food dislikes than did boys. Selected as liked foods were fruits, rice noodle soup, biscuits, and peanuts. Disliked foods were liver, green onions, onions, green pepper, mushrooms, oysters, shellfish, and pork. Items which children never ate before were liver, mushrooms, fish cake, boiled rice mixed with sorghum, mayonnaise, and fresh water firsh. Reasons which children gave for dislike were undesirable flavor and odor. 2) Food $behavior{\cdots}{\cdots}It$ was found that boys liked sweet and salty flavors more than did the girls who more often liked sour flavor. The majority of children enjoyed evening meals more than lunch and breakfast. A number of children skipped breakfast because of lack of appetite or lack of time before going to school. Snacks were the most popular food, especially among girls. Their snacking habits were formed by the encouragement of the mother, and the relieve boredom. Educational backgrounds of mothers and family economical levels of children were remarkable correlated with mothers' attitudes toward feeding of children. There were several interesting findings relating body stature to some other responses; such as that the obese child has a small number of brothers, higher birth order, higher educated mothers and higher family cultural background. It was also discovered that food perference, except for fat and oil group foods was not related to body stature. Sweet taste was liked best and pepperly taste was mostly disliked. Sour taste was popular in the group of underweight. Underweight children were more finicky, disliked snacking, and didn't get much attention from their mothers. 3) Correlation between body stature and nutrition during their infancy. The majority of children, both from obese and underweight, were breast fed as infant. Twenty five per cent of obese children and 17.4 per cent of underwight children started weaning at $1{\sim}6$ months old. The most popular supplemental food of weaning was cereal gruel for the obese group, while boiled white rice and cereal gruel were most common for the underweight group. Highly significant relationships were found between stature of parents and their children. In the obese group 47.8 per cent of fathers and 45.9 per cent of mothers were overweight; however, none of the fathers and only one mother was found to be underweight. In daily food consumption patterns, meals consisting of bread or noodle were popular in the obese group but disliked by the underweight group. The study found clear contrast in that the obese group liked meat and fish while the underweight group liked fruits and vegetables, especially kimchee. The obese children desired to eat cereal foods, milk and milk products, and fat foods while the underweight group desired to eat fruits and vegetables. Frequency of snacks per day was much greater in the obese group. Foods which mothers believed to be good for the health were carrots, cucumbers, fruits, milk, potatoes, sweet potatoes, and breads, while sweet foods such as candies, drinks. chocolate were considered not good for the teeth. Watching television was not significantly related to statures of children. Most significant relationships were found beween frequencies of family guest meals/and eating-out, and children's statures. Nutritional problems which have been considered for the malnourished children in addition to those of children who have a tendency toward obesity, must be taken into consideration in the development of proper nutrition education through the channels of regular school teaching and teaching by parents in the homes. Korean standards of anthropometric measurements for children should be revised, current measurements show much higher figures than present Korean standards.

  • PDF

광원의 종류에 따른 복합레진의 중합거동 및 중합률에 관한 연구 (THE POLYMERIZATION RATE AND THE DEGREE OF CONVERSION OF COMPOSITE RESINS BY DIFFERENT LIGHT SOURCES)

  • 류주희;이인복;유현미;김미자;석창인;권혁춘
    • Restorative Dentistry and Endodontics
    • /
    • 제29권4호
    • /
    • pp.386-398
    • /
    • 2004
  • Objectives: The purpose of this study was to observe the reaction kinetics and the degree of polymerization of composite resins when cured by different light sources and to evaluate the effectiveness of the blue Light Emitting Diode Light Curing Units (LED LCUs) compared with conventional halogen LCUs. Materials and Methods: First, thermal analysis was performed by a differential scanning calorimeter (DSC). The LED LCU (Elipar Freelight, $320{\;}mW/\textrm{cm}^2$) and the conventional halogen LCU (XL3000, $400{\;}mV/\textrm{cm}^2$) were used in this study for curing three composite resins (SureFil, Z-250 and AEliteFLO). Second. the degree of conversion was obtained in the composite resins cured according to the above curing mode with a FTIR. Third, the measurements of depth of cure were carried out in accordance with ISO 4049 standards. Statistical analysis was performed by two-way ANOVA test at 95% levels of confidence and Duncan's procedure for multiple comparisons. Results: The heat of cure was not statistically different among the LCUs (p > 0.05). The composites cured by the LED (Exp) LCUs were statistically more slowly polymerized than by the halogen LCU and the LED (Std) LCU (p < 0.05). The composite resin groups cured by the LED (Exp) LCUs had significantly greater degree of conversion value than by the halogen LCU and the LED (Std) LCU (p =0.0002). The composite resin groups cured by the LED (Std) LCUs showed significantly greater depth of cure value than by the halogen LCU and the LED (Exp) LCU (p < 0.05).

Celay/In-Ceram, Conventional In-Ceram, Empress 2 전부도재관의 변연적합도에 관한 비교 연구 (MARGINAL FIT OF CELAY/IN-CERAM, CONVENTIONAL IN-CERAM AND EMPRESS 2 ALL-CERAMIC SINGLE CROWNS)

  • 양재호;여인성;이선형;한중석;이재봉
    • 대한치과보철학회지
    • /
    • 제40권2호
    • /
    • pp.131-139
    • /
    • 2002
  • There have been many studies about marginal discrepancy of single restorations made by various systems and materials. But many of statistical inferences are not definite because of sample size, measurement number, measuring instruments. etc. The purpose of this study was to compare the marginal adaptations of the anterior single restorations made by different systems and to consider more desirable statistical methods in analysing the marginal fit. The in vitro marginal discrepancies of three different all-ceramic crown systems (Celay In-Ceram. Conventional In-Ceram. IPS Empress 2 layering technique) and one control group (PFM) were evaluated and compared. The crowns were made from one extracted maxillary central incisor prepared with a 1mm shoulder margin and $6^{\circ}$ taper walls by milling machine. 10 crowns per each system were fabricated. Measurements or a crown were recorded at 50 points that were randomly selected for marginal gap evaluation. Non-parametric statistical analysis was performed for the results. Within the limits of this study, the following conclusions were drawn: 1 Mean gap dimensions and standard deviations at the marginal opening for the maxillary incisor crowns were $98.2{\pm}40.6{\mu}m$ for PFM, $83.5{\pm}18.7{\mu}m$ for Celay In-Ceram, $104.9{\pm}44.1{\mu}m$ for conventional In-Ceram, and $45.5{\pm}11.5{\mu}m$ for IPS Empress 2 layering technique. The IPS Empress 2 system showed the smallest marginal gap (P<0.05). The marginal openings of the other three groups were not significantly different (P<0.05). 2 The marginal discrepancies found in this study were all within clinically acceptable standards ($100\sim150{\mu}m$). 3. When the variable is so controlled that the system may be the only one, mean value is interpreted to be the marginal discrepancy of a restoration which is made by each system and standard deviation is to be technique-sensitivity of each one. 4. From the standard deviations. the copy-milling technique (Celay/In-Ceram) was not considered to be technique-sensitive in comparison with other methods. 5. Parametric analysis is more reliable than non-parametric one in interpretation of the mean and standard deviation. The sample size of each group has to be more than 30 to use parametric statistics. The level of clinically acceptable marginal fit has not been established. Further studies are needed.

A SUPER-JUPITER MICROLENS PLANET CHARACTERIZED BY HIGH-CADENCE KMTNET MICROLENSING SURVEY OBSERVATIONS OF OGLE-2015-BLG-0954

  • SHIN, I.-G.;RYU, Y.-H.;UDALSKI, A.;ALBROW, M.;CHA, S.-M.;CHOI, J.-Y.;CHUNG, S.-J.;HAN, C.;HWANG, K.-H.;JUNG, Y.K.;KIM, D.-J.;KIM, S.-L.;LEE, C.-U.;LEE, Y.;PARK, B.-G.;PARK, H.;POGGE, R.W.;YEE, J.C.;PIETRUKOWICZ, P.;MROZ, P.;KOZLOWSKI, S.;POLESKI, R.;SKOWRON, J.;SOSZYNSKI, I.;SZYMANSKI, M.K.;ULACZYK, K.;WYRZYKOWSKI, L.;PAWLAK, M.;GOULD, A.
    • 천문학회지
    • /
    • 제49권3호
    • /
    • pp.73-81
    • /
    • 2016
  • We report the characterization of a massive (mp = 3.9±1.4Mjup) microlensing planet (OGLE-2015-BLG-0954Lb) orbiting an M dwarf host (M = 0.33 ± 0.12M) at a distance toward the Galactic bulge of $0.6^{+0.4}_{-0.2}kpc$, which is extremely nearby by microlensing standards. The planet-host projected separation is a⊥ ~ 1.2AU. The characterization was made possible by the wide-field (4 deg2) high cadence (Γ = 6 hr–1) monitoring of the Korea Microlensing Telescope Network (KMTNet), which had two of its three telescopes in commissioning operations at the time of the planetary anomaly. The source crossing time t* = 16 min is among the shortest ever published. The high-cadence, wide-field observations that are the hallmark of KMTNet are the only way to routinely capture such short crossings. High-cadence resolution of short caustic crossings will preferentially lead to mass and distance measurements for the lens. This is because the short crossing time typically implies a nearby lens, which enables the measurement of additional effects (bright lens and/or microlens parallax). When combined with the measured crossing time, these effects can yield planet/host masses and distance.

X선 회절법에 의한 전남지역 천일염의 결정학적 특성 (Crystallographical Characteristics of Solar Salts Produced from Jeonnam Area by X-Ray Diffraction Technique)

  • 정병조;김용;김창대;현승철;함경식
    • 한국식품영양과학회지
    • /
    • 제38권9호
    • /
    • pp.1284-1288
    • /
    • 2009
  • 본 연구는 천일염 결정 내에 함유된 무기물들의 화합물 결정 상태를 비파괴적인 방법인 XRD 방법으로 규명할 수 있는지를 조사하기 위하여, 전남 서남해안의 12개 지역 염전에서 채취한 12종의 천일염들에 대하여 X선 회절선을 측정하고, 이 X선 회절선 스펙트럼을 EDX 측정 결과와 JCPDS 데이터와의 비교 분석을 통하여 천일염 결정 내에 함유된 무기물들의 화합물 결정 상태를 처음으로 확인하였다. 특히 아직까지 알려져 있지 않았던 무기질 화합물 결정들이 천일염에 함유되어 있음을 밝혀냈는데, 신안 증도와 신의의 천일염에서 $Na_2S$, 신안 비금의 천일염에서 $KMgCl_3$, 신안 도초에서 $Ca(ClO_3)_2$, 해남 송지에서 $CaAl_4O_7$, 고흥에서 $CaSiO_3$, $CaCl_2$, 해남 토판 소금에서 NaKCl 등이 관측되었다. 또한 XRD 측정 결과는 천일염의 결정구조가 소금의 입방구조인 NaCl구조를 그대로 유지함을 보였으며, 격자상수도 정제염이나 시약염에 비해 거의 변화가 없는 비슷한 값을 보였다. 그러나 FE-SEM으로부터 조사한 천일염의 외형적 결정 구조는 정제염과 시약염에서 보이는 소금 NaCl의 결정구조인 정육면체의 결정 형태와는 달리 이들이 적층되어 이루어진 결정 형태의 특징을 보였다. 또한 결정 입자의 크기에 있어서도 정제염이나 시약염보다 수백 배에 이르는 특징을 보였다.

국부통계 산출을 위한 입목자산 분류기준의 정립 (Reviewing Classification Scheme of Timber Assets for the National Accounting in Korea)

  • 정세경;김영환
    • 한국산림과학회지
    • /
    • 제96권6호
    • /
    • pp.724-729
    • /
    • 2007
  • 우리나라의 산림자원은 그 양적인 증대에도 불구하고 임업의 낮은 채산성으로 인해 경제적인 자산으로서의 가치를 인정받지 못하고 있다. 1998년에 시행된 제4회 국부통계 조사 시 입목자산에 대한 통계를 산림청에서 추계한 이후, 입목자산에 대한 올바른 평가가 이루어지지 못하고 있으며, 심지어 입목자산의 분류기준에 대해서도 명확한 기준이 정립되어 있지 못한 실정이다. 따라서 본 연구에서는 현재 우리나라 자산분류를 규정하고 있는 '1993 국민계정체계(상 하)'와 그 모태가 된 UN의 '1993 SNA' 원문을 대상으로 입목자산과 관련된 조항들을 비교 검토함으로써 입목자산의 분류를 위한 기준을 정립하고차 하였다. 그 결과 기존의 '1993 국민계정체계'는 인공조림여부에 따라서 천연림은 비생산자산으로 인공림은 생산자산으로 구분하고 있으나, 이는 원문인 '1993 SNA'의 취지를 충분히 반영하지 못하는 것으로 분석되었다. '1993 SNA'의 원문에서는 인공조림의 여부보다는 오히려 소유관계와 제도권 관리주체의 책임 하에서 통제 관리되는가의 여부를 기준으로 적용하여, 천연림의 경우에도 생산자산으로 구분하는 것이 가능하도록 규정하고 있었다. 따라서 '1993 SNA' 원문의 취지에 부합되도록 '1993 국민계정체계'를 개선하고 입목자산에 대한 분류기준을 정립하도록 개선안을 제시하였다.

한국 성인의 상악 전치부 인공치아 선택기준에 관한 계측학적 연구 (A STUDY ON THE SELECTION OF THE MAXILLARY ANTERIOR ARTIFICIAL TEETH IN KOREAN ADULTS)

  • 안현정;양홍서;박하옥
    • 대한치과보철학회지
    • /
    • 제40권5호
    • /
    • pp.484-492
    • /
    • 2002
  • The selection of the maxillary anterior artificial teeth is made primarily for esthetics and they must be in harmony with the surrounding oral environment. However the selection of artificial teeth is based on the large degree of subjective judgement or the dentists, therefore, this is one of the most unscientific processes. This study was performed to determine clinically whether there is correlation among the width of the maxillary central incisor(WMCI), the intercanine distance (ICD) the facial width(FW), and the interalar nasal width(IAW) in Korean adults, and to provide the selection standards for the maxillary anterior artificial teeth. The casts were obtained from 91 undergraduate dental students(49 males and 42 females) with Angle's class I occlusion presenting well-arranged intact anterior teeth. The WMCI and ICD were measured on the casts with a vernier calipers($Miltex^{(R)}$, Germany). The photographic procedures under standardized conditions were performed to record each subject's frontal face using digital camera($Olympus^{(R)}$, C-2500L, Japan). The FW and IAW were measured with image analyzer($Image-Pro^{(R)}$ PLUS. media cybermetrics. USA). The results were obtained as follows : 1. The mean WMCI was $8.11{\pm}0.67mm$, ICD was $37.88{\pm}2.15mm$, FW was $141.29{\pm}5.84mm$. and IAW was $37.85{\pm}2.29 mm$. 2. The ratios of FW/WMCI, FW/ICD, IAW/ICD were 17.4, 3.7, 1.0 respectively. 3. All measurements(WMCI, ICD, FW, and IAW) of male group were longer than those of female group significantly in Student's t-test(p<0.01). 4. There was significant correlation between WMCI, ICD, FW, and IAW in Pearson's correlation analysis(p<0.01). 5, The relationship between IAW and ICD shows the strongest correlation among six combinations in linear regression analysis($R^2$=0.753, Y=7.046+0.815X). The FW and IAW could be very reliable guides for the selection of the maxillary anterior artificial teeth.

정상교합자의 골격형에 따른 치아치조보상 (Dentoalveolar Compensation according to Skeletal Patterns of Normal Occlusion)

  • 이신재;장영일;구승준
    • 대한치과교정학회지
    • /
    • 제32권2호통권91호
    • /
    • pp.91-105
    • /
    • 2002
  • 일반적으로 교정 환자의 문제점을 파악하고 치료 계획을 수립할 때에 여러 분석법의 정상치를 기준으로 하는 경우가 많다. 하지만 다양한 악골관계 하에서 정상적인 악궁관계를 유지하기 위해 3차원적으로 발생하는 치아치조부 보상 기전을 고려한다면 좀 더 개별화된 치료 목표와 치료계획을 수립하는데 도움이 될 수 있을 것이다. 이에 본 연구에서는 정상교합자 125명의 측모 두부계측방사선사진을 계측하여 정상교합자의 골격양상의 다양성을 살펴보았다. 또한 여러 골격계측 기준을 이용한 군집분석을 적용하여 정상교합자의 골격형을 전후방으로 세 군, 수직적으로 세 군으로 분류하고 각 골격형에 따른 치아치조부 보상양상을 조사하여 다음과 같은 결과를 얻었다. 1. 정상교합자의 전후방적, 수직적 악골관계는 매우 다양하였다. 2. 하악골이 상악골에 비해 전방 위치할수록 상악 전치는 순측으로 경사 되고 하악 전치는 설측으로 경사 되며 교합평면의 경사도는 완만해졌다. 3. 수직적인 골격양상일수록 상악 전치부의 치아치조 고경이 증가하고, 하악 구치부의 치아치조 고경이 감소하였으며 구개평면에 대한 상악 구치와 하악평면에 대한 하악 전치 및 하악 구치는 직립 하였고 교합평면과 하악평면사이의 각(OMA)은 증가하였다. 4. 상악 전치보다 하악 전치에서 전후방 및 수직적인 악골관계에 대해 더 많은 치아치조부 보상양상을 보였다.

중국 29개 성의 환경성과 평가 - 통합오염원 단위를 중심으로 - (Estimation of Environmental Performance in 29 Chinese Provinces - Focused on Integrated Pollution Intensity -)

  • 김광욱;박혜란;강상목
    • 환경정책연구
    • /
    • 제10권1호
    • /
    • pp.71-91
    • /
    • 2011
  • 본 논문의 목적은 1998~2007년 중국 29개 성(省)을 대상로 통합오염원단위지수를 계측하고, 급격한 경제성장에 따른 환경성과의 변화를 파악하는 것이다. 각 성별 총생산, 자본 노동, 대기오염배출량($CO_2$, $SO_x$)을 활용한 통합오염원단위지수의 계측 결과, 상대적으로 경제성장의 속도가 빠르고 소득수준이 높은 동부지역의 수치가 중 서부에 비해 매우 낮은 수준을 보였으며, 시계열적으로도 이러한 경향은 더욱 뚜렷함을 확인할 수 있었다. 본 논문은 통합오염원단위지수의 변화에 미치는 소득수준 및 기타변수의 영향을 분석하기 위해 추가적인 패널회귀분석을 시도하였다. 설명변수로는 소득수준을 나타내는 대표적 변수인 1인당 총생산과 함께 제조업 비중, 1인당 환경보호투자, 해외직접투자유입 등을 포함하였으며, 전반으로 높은 통계적 유의성을 보였다. 소득수준의 증가에 따라 통합오염원단위의 지속적인 하락경향을 확인할 수 있었으며, 이는 중국의 경제성장과정이 환경부담을 완화시키는 방향으로 작용하고 있음을 의미한다. 또한 해외직접투자유입변수의 계수가 모든 모형에서 통합오염원단위지수와 강한 음(-)의 관계를 보이는 것은 외국자본유입이 선진기의 보급 및 환경수요의 증가를 유도하여 환경적으로 긍정적인 영향을 미치는 것을 의미한다. 마지막으로 1인당 환경보호투자변수는 대부분의 모형에서 통계적 유의성을 보여주지 못하였다.

  • PDF