• 제목/요약/키워드: Over-the-head

검색결과 1,193건 처리시간 0.031초

Dislodgement resistance of modified resin-bonded fixed partial dentures utilizing tooth undercuts: an in vitro study

  • Doh, Re-Mee;Lee, Keun-Woo
    • The Journal of Advanced Prosthodontics
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    • 제1권2호
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    • pp.85-90
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    • 2009
  • STATEMENT OF PROBLEM. Over the years, resin-bonded fixed partial dentures (RBFPDs) have gone through substantial development and refinement. Several studies examined the biomechanics of tooth preparation and framework design in relation to the success rate of RBFPDs and considered retention and resistance form essential for increase of clinical retention. However, these criteria required preparations to be more invasive, which violates not only the original intentions of the RBFPD, but may also have an adverse effect on retention due to loss of enamel, an important factor in bonding. PURPOSE. The object of this in vitro study was to compare the dislodgement resistance of the new types of RBFPDs, the conventional three-unit fixed partial denture, and conventional design of RBFPD (Maryland bridge). MATERIAL AND METHODS. Fifty resin mandibular left second premolars and second molars were prepared on dentiforms, according to the RBFPD design. After model fabrication (five group, n = 10), prostheses were fabricated and cemented with zinc phosphate cement. After cementation, the specimens were subjected to tensile loading at a cross head speed of 4 mm/min in a universal testing machine. The separation load was recorded and analyzed statistically using one-way analysis of variance followed by Duncan's multiple range test. RESULTS. Group V, the pin-retained RBFPDs, had the highest mean dislodgement resistance, whereas specimens of group II, the conventional RBFPDs, exhibited a significantly lower mean dislodgement resistance compared to the other 4 groups (P <.05). There were no significant differences between group I, III, and IV in terms of dislodgement resistance (P>.05). Group V had the highest mean MPa (N/$mm^2$) (P <.05). There was no significant difference between groups I, II, III and IV (P > .05). CONCLUSION. Within the limits of the design of this in vitro study, it was concluded that: 1. The modified RBFPDs which utilizes the original tooth undercuts and requires no tooth preparation, compared with the conventional design of RBFPDs, has significantly high dislodgement resistance (P < .05). 2. The modified RBFPDs which utilizes the original tooth undercuts and requires minimal tooth preparation, compared with the conventional FPDs, has significantly no difference in retention and dislodgement resistance)(P>.05). 3. The pin-retained FPDs showed a high dislodgement resistance compared to the conventional three-unit FPDs (P<.05).

선형절삭시험과 적외선 열화상 측정을 통한 픽커터 작용력과 발생 온도의 상관관계 분석 (Correlation Analysis of Cutter Acting Force and Temperature During the Linear Cutting Test Accompanied by Infrared Thermography)

  • 장수호;강태호;이철호;정호영;최순욱
    • 터널과지하공간
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    • 제33권6호
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    • pp.519-533
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    • 2023
  • 본 연구에서는 평균 압축강도가 100 MPa 이상인 암석에 대해 픽커터의 선형절삭시험을 실시하였고, 적외선 열화상 카메라를 통해 측정된 픽커터 절삭 시의 발생 온도와 커터 작용력과의 상관관계를 분석하였다. 모든 시험조건에서 최대 온도는 치핑이 발생하는 암석면에서 측정되었고, 암석에 발생한 온도는 픽커터의 작용력과 밀접한 상관관계를 나타내었다. 반면, 픽커터에 발생하는 온도는 대기 온도 대비 최대 36℃ 이내로 상승하였고 커터 작용력과의 상관관계도 뚜렷하지 않았다. 이는 실험실 조건의 짧은 절삭거리와 텅스텐 카바이드 삽입재의 높은 열전도 특성이 원인인 것으로 사료된다. 단, 픽커터의 주요 부위 중에 텅스텐 카바이드 삽입재에 상대적으로 높은 온도가 유지되는 것으로 나타나, 픽커터 절삭 성능의 유지를 위해서는 삽입재와 헤드부 사이에 보강을 실시하거나 픽커터 제작 시에 은납 공정의 품질을 향상시키는 것이 필요할 것으로 판단된다.

팔로사징증의 근치 수술에 관한 임상적 고찰 (Clinical Review about Corrective Surgery of Tetralogy of Fallot)

  • 조광현
    • Journal of Chest Surgery
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    • 제24권7호
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    • pp.674-684
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    • 1991
  • The surgical treatment of tetralogy of Fallot [TOF] was initiated by Blalock and Taussig in 1945 with the establishment of the subclavian artery to pulmonary artery anastomosis. In an imaginative and daring effort, in 1954, Lillehei and collaborators [1955] using controlled cross-circulation, carried out the first intracardiac repair of TOF by closing the ventricular septal defect [VSD] and relieving the pulmonary stenosis under direct vision. Nowadays, total correction is the ideal operation for treatment of TOF and is accomplished with extracorporeal circulation. And the results of surgery for TOF have steadily improved over the years, thanks to important contributions of many surgeons. Nevertheless because of its protean physiologic and anatomic presentation, TOF continues to offer challenges to cardiologist and cardiac surgeons. Thirty two cases of TOF have undergone total corrective surgery using extracorporeal circulation in the Department of Thoracic & Cardiovascular Surgery, Pusan Paik Hospital, Inje University, from Oct. 1985 to Feb. 1990. Clinical considerations were applied to these cases and the results were obtained as follows. 1. The heart lung machine used for extracorporeal circulation was SarnsO 7000, 5-head roller pump, and the number and type of oxygenators were 10 of bubble type and 22 of membrane type. The mean bypass time was 148.9 minutes and the mean aortic cross clamp time was 123.8 minutes. The GIK [glucose-insulin-potassium] solution was used as cardioplegic solution for myocardial protection during operation. 2. 20 cases were male and 12 were female, the mean age was 8 years old and the mean body weight was 25Kg. 3. The preoperative symptoms were cyanosis [29 cases], squatting [27 cases] and etc. The mean values of preoperative Hb., Hct., and SaO2 were 16.5 gm /dl, 50.3%, and 78.5%. 4. Combined anomalies were noticed in 16 cases [50%]. Among them 10 cases were PFO and 6 cases were ASD. 5. The degree of aorta overriding were 25% in 5 cases, 25 ~ 50% in 22 cases and above 50% in 5 cases. The dPA/Ao [ratio of diameter of pulmonary artery trunk to ascending aorta] were below 25% in 5 cases, 25 ~ 50% in 10 cases, 50 ~ 70% in 6 cases and above 75% in 11 cases. 6. The types of RVOT [right ventricular outflow tract] stenosis were valvular and infundibular in 14 cases [43.6%], diffuse hypoplastic type in 12 cases [37.5%], infundibular in 5 cases, and valvular and supravalvular in 1 case. 7. One stage radical corrective surgery was applied to the all cases. In widening of the RVOT, 3 types of patches were used: MVOP [monocusp ventricular outflow patch, Polystan BioprosthesesO] in 3 cases, knitted Dacron vessel patches in 2 cases, and double layer with bovine pericardium and woven Dacron prosthesis in 26 cases. 8. Postoperative complications were occurred in 15 cases. Among them, low output syndrome were occurred in 10 cases [31.3%] and 2 of them were expired postoperatively.

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Anticipating the Need for Healthcare Resources Following the Escalation of the COVID-19 Outbreak in the Republic of Kazakhstan

  • Semenova, Yuliya;Pivina, Lyudmila;Khismetova, Zaituna;Auyezova, Ardak;Nurbakyt, Ardak;Kauysheva, Almagul;Ospanova, Dinara;Kuziyeva, Gulmira;Kushkarova, Altynshash;Ivankov, Alexandr;Glushkova, Natalya
    • Journal of Preventive Medicine and Public Health
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    • 제53권6호
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    • pp.387-396
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    • 2020
  • Objectives: The lack of advance planning in a public health emergency can lead to wasted resources and inadvertent loss of lives. This study is aimed at forecasting the needs for healthcare resources following the expansion of the coronavirus disease 2019 (COVID-19) outbreak in the Republic of Kazakhstan, focusing on hospital beds, equipment, and the professional workforce in light of the developing epidemiological situation and the data on resources currently available. Methods: We constructed a forecast model of the epidemiological scenario via the classic susceptible-exposed-infected-removed (SEIR) approach. The World Health Organization's COVID-19 Essential Supplies Forecasting Tool was used to evaluate the healthcare resources needed for the next 12 weeks. Results: Over the forecast period, there will be 104 713.7 hospital admissions due to severe disease and 34 904.5 hospital admissions due to critical disease. This will require 47 247.7 beds for severe disease and 1929.9 beds for critical disease at the peak of the COVID-19 outbreak. There will also be high needs for all categories of healthcare workers and for both diagnostic and treatment equipment. Thus, Republic of Kazakhstan faces the need for a rapid increase in available healthcare resources and/or for finding ways to redistribute resources effectively. Conclusions: Republic of Kazakhstan will be able to reduce the rates of infections and deaths among its population by developing and following a consistent strategy targeting COVID-19 in a number of inter-related directions.

연무자리돔, Chromis fumea (Pisces: Pomacentridae)의 산란보호, 난발생 및 자어의 형태발달 (Male Parental Care, Egg and Larval Development of the Smoky Damselfish, Chromis fumea (Pisces: Pomacentridae))

  • 김진구;김용억;박진우
    • 한국어류학회지
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    • 제13권3호
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    • pp.166-172
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    • 2001
  • 1995년 8월 제주도 근해에서 스쿠바 다이빙하여 연무자리돔의 산란보호행동을 관찰하였으며, 채집된 연무자리돔의 난은 부경대학교로 운반하여 부화, 사육하였다. 연무자리돔의 난은 평탄하고 단단한 기질의 산란소에 한층으로 부착되어 있었고, 수컷은 산란소 주위에서 접근해오는 다른 어종을 공격하는 산란보호행동을 나타내었다. 수정난은 무색투명하고, 타원형을 띠며, 부착사를 가진 침성부착난으로 난경은 장경이 0.73~0.88 mm, 단경이 0.50~0.56 mm이었다. 시간의 경과에 따른 난경의 변화는 T-test 결과 장경은 유의한 차이를 나타내었으나 (p<0.01) 단경은 유의한 차이가 없었다 (p>0.05). 수정난은 $23.0{\sim}25.5^{\circ}C$ 수온 범위에서 사육되었으며, 부화까지는 4~5일이 소요되었다. 부화자어는 척색장 1.10~1.61 mm로 21개의 근절을 가지고 있고 입은 닫힌 상태이나 항문은 열려 있으며, 항문전장은 척색장의 45.8%에 달하였고, 흑색소포는 두정부, 눈, 복강의 등쪽 및 꼬리의 배쪽 가장자리에 분포하였다. 부화자어의 난황과 유구는 부화 후 3~4일만에 완전히 흡수되어, 이 시기에 후기자어로 이행하였다. 부화 후 3일째 자어는 척색장 1.9~2.4 mm로 25개의 근절을 가지며, 빠르게 성장하였고, 부화 후 9일째 자어는 척색장 2.9 mm로 복부 등쪽에 처음으로 부레가 출현하였으며, 흑색소포는 형태적으로 커지면서 수적으로는 감소하였다.

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특정 응용을 위한 수중센서네트워크에서 에너지 효율적인 데이터통합 방법 연구 (A Study on the Energy Efficient Data Aggregation Method for the Customized Application of Underwater Wireless Sensor Networks)

  • 김성운;박선영;유흥식
    • 한국멀티미디어학회논문지
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    • 제14권11호
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    • pp.1438-1449
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    • 2011
  • 수중센서네트워크 응용은 적용 대상 및 지역적 범위에 따라 효과적인 모델링이 필요하고 이러한 특정화된 응용 모델 기반에서 에너지 효율적인 데이터통합 방법이 필요하다. 본 논문에서는 수중에 고정된 닻으로 좌우 움직임이 가능한 센서노드들로 구성된 3차원 육각기둥 벌집모델에 기초하여 오염 및 침투 감시용 응용 모델링 및 이를 기초로 한다. 이 모델에서는 층별 구성 셀들의 이벤트 감지 데이터와 해당 층 위치 데이터를 수면기지국까지 효율적으로 전송하면 그 목적이 달성된다. 여기서 기존의 데이터통합 방법을 적용하면 최소 경로나 멀티캐스트 트리에 기반된 관계로 과정이 복잡하여 에너지 비효율적이다. 본 논문에서는 층별 셀들에서 발생되는 이벤트 데이터를 해당 층 헤드노드로 효과적으로 전달하기위한 클러스터 내부에서 클러스터 기반의 에너지 효율적인 세 가지 가능한 데이터통합 방법을 제시한다. 그리고 층별 클러스터 헤드노드에서 수집된 데이터를 기지국까지 효율적으로 전달하기위한 클러스터 간 세 가지 데이터통합 방법도 제시한다. 제시된 데이터통합 방법들은 주어진 영역 침투 감시등과 같은 특정화된 응용 대상으로 동작의 단순성과 에너지 효율화 측면이 주된 고려 요소이다. 마지막으로 시뮬레이션과 성능 비교분석을 통해 제시된 클러스터 층별 및 층간 데이터통합 방법의 조합 중 가장 우수한 에너지 효율적인 데이터통합 방법을 도출한다.

경주지역 유치원 아동들의 식습관과 영양소 섭취상태 (The Status of Eating Habits and Nutrient Intakes of Preschool Children in Kyungjoo)

  • 최미자;정연수
    • 대한지역사회영양학회지
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    • 제11권1호
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    • pp.3-13
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    • 2006
  • The purpose of this study is to estimate the nutrient intakes and food habits among preschool children in Kyungjoo city. The subjects were 210 preschool children, aged 4 - 6 years. Measurements of the weight, height, chest circumference, and head circumference of the children were conducted. And general home environment and factors related to eating habits for preschool children were collected using a questionnaire that included information about family income, parents' education and occupations. The average weight-length index (WLI) for the subjects was $103.9\%$. Using the WLI, $20.0\%$ of the preschool children were underweight, $48.6\%$ were normal, $19.0\%$ were overweight, and $12.3\%$ were obese. On the R$\ddot{o}$hrer index, $13.8\%$ of the preschool children were underweight, $38.5\%$ were normal, and $47.7\%$ were over weight or obese. The average daily intake ($\%$ of RDA) of energy and each nutrient was 1323.5 kcal ($81.3\%$), Ca 484.3 mg ($80.7\%$), Fe 7.05 mg ($88.1\%$), vitamin A 420.0 RE ($105\%$), vitamin $B_{2}$ 0.76 mg ($95.0\%$), vitamin $B_{2}$ 0.87 mg ($87.0\%$), and vitamin C 53.1 mg ($106.2\%$) , respectively. In particular, older subjects had lower intake in RDA $%$ of calcium and iron. The energy intake ratio from snacks was much higher than the recommended level of the preschool children. With regard to frequency of regularity of breakfast, $1.9\%$ of preschool children skipped every morning and $7.6\%$ of the children skipped more than 5 per week. With regard to the intake frequency of vegetables, fruits, complex carbohydrates, and milk, $13.3\%$, $19.9\%$, $22.8\%$, and $41.8\%$ of the children ate more than 5 times per week. The eating habit score was positively correlated (r = 0.18, P < 0.05) with household income. This study suggests that nutrition education to increase fruit and vegetable consumption for preschool children should be emphasized. Also a nutrition education program is needed to enhance consuming calcium and iron intake for adequate growth.

광주, 본촌지역의 지하수의 수화학적 특성과 오염 (Chemical Characteristics and Pollution of Groundwater in the Ponchon Area, Kwangju)

  • 양해근;김인수;최희철;김정우
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제6권4호
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    • pp.83-95
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    • 2001
  • 본 연구에서는 광주 본촌분지를 대상으로 지하수의 오염현황을 분석하고, 수문지질구조와 수두의 분포 그리고 지하수의 수화학적 조성으로부터 오염기구를 검토하였다. 그 결과는 다음과 같다. 분지의 수두분포는 대체적으로 지형면을 반영하고 있으나, 과잉양수에 의한 지하수 유동계의 변형이 나타나고 있다. 농경지와 주거지가 혼재된 분지 북부에서는 Cl와 EC, Na, $NO_3$농도가 비교적 높았으며, 공업단지가 입지한 분지 남쪽에서는 $HCO_3$$Ca^{2+}$, $Mg^{2+}$, Zn이 상대적으로 높은 농도를 나타냈다. Cl-과 N $O_3$농도에 의한 오염은 생활.공장폐수에 의한 것으로 추정된다. 그리고, Cl의 경우에는 특정 오염원을 기점으로 하천수계를 따라 오염물질이 확산되는 양상을 보이고 있으며, 오염원의 분포와 농도분포를 고려할 때 오염물질의 수평 분산보다는 공단지역의 과잉양수에 의한 지하수위의 저하로 수직이동이 더 크게 작용하고 있다고 볼 수 있다. 이상으로부터 공단지역에서의 지하수 과잉양수가 지속될 경우, 지형면을 따라 형성된 유동계가 더욱 왜곡되고, 지하수위의 급격한 저하는 분지 북부지역에 까지 미치게 될 것이다. 더욱이 분지 북부의 생활 공장폐수에 의한 염수화 현상 또는 질소오염은 분지 전역으로 확산될 것은 자명하다.현상 또는 질소오염은 분지 전역으로 확산될 것은 자명하다.

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초고성능 콘크리트 바닥판을 위한 스터드 전단연결재의 정적 거동 (Static Behavior of Stud Shear Connector for UHPC Deck)

  • 이경찬;곽종원;박상혁;김지상
    • 콘크리트학회논문집
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    • 제26권5호
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    • pp.573-579
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    • 2014
  • 합성보는 콘크리트 바닥판과 강재 거더로 이루어져 왔으나, 바닥판의 자중을 줄이면서 내구성을 향상시키고 나아가 교량의 강도 및 강성을 향상시키기 위하여 초고성능 콘크리트(UHPC)를 교량 바닥판으로 채용한 합성보가 최근에 제안되고 있다. 이 연구는 기존의 스터드 전단연결재가 UHPC 바닥판을 합성함에 있어 유효한지에 관하여 실험적으로 검토해보고자 한다. 12개의 push-out 시험체를 통하여 UHPC 바닥판에 매립된 스터드 전단연결재의 정적 강도를 평가하였으며, 실험 변수로 바닥판 두께, 스터드 높이 및 지름을 채택하여, 기존에 제한되었던 스터드 지름에 대한 높이의 비율인 형상비와 스터드 머리부 상부 콘크리트 피복두께의 제한을 완화하는 것이 가능한지에 대하여 검토하였다. 이 연구의 실험으로부터 기존 AASHTO LRFD에 제시된 정적 강도평가식을 UHPC에 매립된 스터드 전단연결재에 적용하는 것이 유효함을 확인하였으며, 4이상으로 제한된 형상비는 3.1까지 낮추어도 되며, 50 mm로 제한된 최소 피복두께도 25 mm까지 낮출수 있음을 확인하였다. 다만 Eurocode-4에 제시된 연성도 기준인 특성 상대슬립 6 mm 이상의 기준을 만족하지 못하여, UHPC에 매립된 스터드 전단연결재는 별도의 연성 보강 방안이 채택되지 않는다면 강성 전단연결재로 간주하여야 할 것이다.

농촌거주 외짝가족의 식생활관리 -부부가족과의 비교- (The Odd Pair Family's Dietary management in rural, Korea - Comparison with the Pair Family -)

  • 이승교;원향례;정금주
    • 한국지역사회생활과학회지
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    • 제16권1호
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    • pp.89-103
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    • 2005
  • Recently the rural Korea has been remarkedly changed of family and social value in accordance with the development of industry. The lower economic class made by social economic growth is widespread with increasing aged, specially odd pair family in rural. The purpose of this study was to investigate to help and keep improve health of rural lower economic class, family system by comparing and analyzing the dietary management, between pair and odd pair family, and to get the data helpful the right guidance for rural. The subjects 1870 collected in 9 provinces by sampling with probability proportional to size (PPS). Questionnaire about dietary habit, food cultivation, production and preservation survey was conducted by trained interviewers. The main results were as follows : 1) The characteristics of odd pair families, head of household was female(77%), over 65 years(84.9%), small family(1.76 persons) and lower education(male 7.5 years, female 3.1 years) status. 2) As the states of diets of odd pair family, having breakfast(87.1 %) but one or two kinds of side dishes(31.3 %) only possible to guess lower status of food intake balance. Nutritional supplements(21. 7 %) was lower than that of paired family. 3) The aspects of dietary habit of odd pair family, no instant foods(70.7%), no snack(38.4%) no dine out(69.2%) were common. 4) Dietary habit scores were 7.78 points of odd pair family compared 8.34 points of paired family. 5) Food purchase place of odd pair family was market(44.2%) but super-market(42.7%) of paired family. 6)In odd pair family, seldom traditional dish preparation(62.0%) but prepared winter kimchi(81.9%), comparing seldom traditional dish(38.6%) and winter kimchi(96.4%) in paired family. 7)The food cultivation state was surveyed, pepper( 42.2 %) and chinese cabbage( 43.9 %) were consumed after cultivation, but sesame(59.4%), bean sprout(90.2%), tofu(92.8%) and egg(93.3%) were consumed by purchase in odd pair family.8) Food cultivation score of odd pair family was 2.98/12points significantly lower than 4.50/12 points of paired family(p<0.01). 9) At the status of fermentation food production in odd pair family, Duenjang(72.1 %) and Gochujang(69.7%) Kanjang(68.3%) Kimchi(82.1 %) and Meju(68.3%) were high rate of production, but more frequently producted in pair family. 10) The score of fermentation food production of odd pair family was 8.57/12points but significantly lower than 10.24/12 points of pair family(p<0.0001). 11) Food preservation score 0.48/6 points in odd pair family was not significantly different than that of pair family(1.07/6points).

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