• Title/Summary/Keyword: Force balanced

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A Development of the Strategies for the Agricultural Extension Service through the Farmers' Educational Needs Assessment (농업인의 교육요구를 고려한 농촌지도사업의 발전 방향)

  • Shinn, Yun-Ho;Kim, Dae-Hee
    • Journal of Agricultural Extension & Community Development
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    • v.19 no.1
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    • pp.1-28
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    • 2012
  • The Extension Program accountability will continue to be an influential force to develop agriculture and rural area. As we incorporate new approaches into our service program and respond to new domains of knowledge, we must also consider how our assessment strategies may need to change in order to meet local and other external standards. The main purpose of the study was to be what the best way of Extension Service is set farmers' educational needs met and to be what kind of methodologies and role of Extension system should provide for their faced problem solving effectively. The major results of the study on Farmers' needs toward Korean Extension Services are summarized as follows. First, it is observed that, when the farmers' perceptions were analyzed, the most ranked by the farmers' needs was "having nice extension workers to get advice and solve their problems on the farm in all at once." Farmers had especially more positive attitudes in the categories of interest and careers in ag-technology. To do services level up, the headquarter of Rural Development of Administration must be work with local branches to effectively deliver their missions and educational objectives to target crops and farmers group. And farmers were strongly needed "a specialized service team will be organized" to work closely with operating services for ag-products processing, packing and marketing. The recommendations were made by: farmers' needs should be identified and announced by computer networking development to solve their problems faster. Also, provincial and county level service members should have a chance to working at research institute or related work places with their incentives, which system will be easer to meet farmers' needs and deal with their problems so that the systematic approaches should be managed and recorded their educational attendings, education contents and even their farming corporations. Finally, Agricultural Extension Service should be met to general ag-technology literacy and be balanced with knowledge of other industries and be competitive service with better values in non-agricultural sectors.

A Case Report of Maxillary Complete Edentulous Patient with a Class III Jaw Relations (III급 악골 관계를 가진 상악 편악 무치악 환자의 수복)

  • Park, Mi-hee;Hong, Jun-won;Choi, Jee-ha;Lee, Jung-jun;Park, Ju-mi;Song, Kwang-yeob;Ahn, Seung-geun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.25 no.4
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    • pp.431-436
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    • 2009
  • In a case of class III skeletal patients with severe alveolar bone resorption, it must be a complete denture treatment plan provided stable and durable occlusion. Despite a markedly increased tooth mobility and unfavorable crown-to-root ration due to periodontal tissue breakdown, if the inflammatory process is controlled and an adequate oral hygiene performed, fixed splints will be considered. Patient's discomfort will be eliminated by achievement better clinical tooth mobility using fixed splints. So it can be a cost and time effective treatment option. In this case, it used a T-Scan System for confirmation a bilateral balanced occlusion and a occlusal force distribution reflected a patient's functional mandibular movement.

An Experimental Study on the Wake Characteristics of a Quadrotor UAV (쿼드로터형 무인비행체의 후류 특성에 관한 실험적 연구)

  • Lee, Seungcheol;Chae, Seokbong;Kim, Jooha
    • Journal of the Korean Society of Visualization
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    • v.16 no.1
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    • pp.30-36
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    • 2018
  • In the present study, we investigate the flow characteristics of a quadrotor UAV in a hovering mode by measuring multiple two-dimensional velocity fields in the wake. The experiment is conducted at Re = 24,000 in a chamber large enough to neglect the ground effect, where Re is the Reynolds number based on the rotor chord length and the rotor tip speed. The rotational speed of the rotor is determined by an optical tachometer so that the lift force can be balanced with the weight of the UAV. The velocity field measured on the center plane of the rotor shows that the vortices are shedding from the tip of the rotor, inducing large fluctuations in the streamwise velocity along the wake shear layer. The strength of the rotor-tip vortex shedding is asymmetric with respect to the rotor axis due to the interaction between the rotor and the wake centerline of each rotor is inclined to the center of the UAV due to the pressure difference caused by the induced velocity. The wake from each rotor moves closer to each other while traveling in the streamwise direction, and then is merged together inducing large fluctuations in the transverse velocity. Due to the wake merging, on the center plane of the UAV, the velocity increases in the streamwise direction showing two-peak structure in the streamwise velocity contours.

Calculation of the Rudder Normal Force for a Horn Type Rudder and Twin Rudder (Horn Type 타(舵)와 한쌍(雙)의 타(舵)의 타직압력(舵直壓力) 계산(計算)에 관한 연구(硏究))

  • Seung-Keon,Lee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.4
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    • pp.27-31
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    • 1990
  • To calculate the lift of a thin lifting surface like the ship-rudder, it is popular to replace the lifting surface by a series of vortices. Two methods, which are vortex lattice method and mode function method, are frequently used to distribute the vortices on the lifting surface. In this paper, the intermediate way of two mentioned calculation method is carried out to exploit the merits of them. The basic concept of this method is to divide the lifting surface with several strips in span-wise and replace vortices to the chord-wise at each strips. A horn type semi-balanced rudder is chosen for the real method, and the validity of the proposed calculation is pursued by the open water test of the same rudder. Finall, this method is applied to the calculation of the interference between the two homogenous rudders siting parallel to the free stream.

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A Comparison of Three Stainless Steel Instruments in the Preparation of Curved Root Canals in vitro (세 종류의 Stainless Steel File을 이용한 만곡근관 형성 후 근관형태 변화에 관한 비교 연구)

  • Young-Tae Kim;Seung-Ho Baek;Kwang-Sik Bae;Sung-Sam Lim;Soo-Han Yoon
    • Restorative Dentistry and Endodontics
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    • v.26 no.1
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    • pp.9-15
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    • 2001
  • 통상적인 근관형성 과정에서 근관형태의 직선화 경향을 발견할 수 있으며, 그 결과 만곡이 심한 근관에서 이상적인 근관형태를 얻기가 어렵다. 이를 극복하기 위한 많은 기구들과 근관 성형법들이 개선되고 소개되었다. 본 연구에서는 최근에 개발된 직사각형의 단면을 가지는 stainless steel file인 RT file과 Flex-R file, K-file을 이용하여 만곡근관 형성 후 최종 근관형태를 비교하여 각 file을 평가하고자 한다. 본 실험은 Bramante등의 방법을 변형하여 술 전의 근관형태와 술 후의 근관형태를 비교하였다. Schneider의 방법을 변형하여 3차원적 만곡을 계산하여 12도에서 36도 이내에 만곡도를 가진 근관을 선택하였다. 49개의 발거된 상악대구치 협측근관이나 하악대구치 근심근관을 3개의 군으로 나누고 레진과 플라스틱으로 제작된 mold에 투명한 교정용 레진으로 매몰하였다. 근첨에서 2.5, 5, 8mm지점에서 절단하여 각 mold에서 재조립한 후 다음과 같이 근관형성을 시행하였다. 제 1군은 SS K-file을 이용하여 step-back 방법 ; 제 2군은 Flex-R file을 이용하여 balanced force 방법 ; 제 3군은 RT file을 이용하여 step-back 방법으로 근관 형성하였다. 술 전과 술 후에 각 시편들을 체현미경으로 사진촬영하여 근관 중심 위치 이동률, 근관형성으로 삭제된 상아질양, 근관형성 후 모양을 Sigma scan/ image software program으로 계산하고 One way ANOVA로 통계적 유의성을 검증하여 다음과 같은 결론을 얻었다. 1. RT file이 치근단에서 K-file보다 유의성 있게 근관의 중심을 유지하는 것으로 보였다. 치아 중앙부에서는 RT file과 Flex-R file이 K-file에 대해 유의성 있게 우수한 것으로 나타났다. 2. 근관형성 후 삭제된 상아질양에서는 치근단에서 RT file이 적게 나왔으나 유의성은 없었다. 3. 근관형성 후 절단면 모양은 원형, 타원형, 불규칙한 형태들이 다양하게 나타났고 각 군간에 유의성 있는 차이는 없었다.

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Epithelial to mesenchymal transition (EMT) of feto-maternal reproductive tissues generates inflammation: a detrimental factor for preterm birth

  • Menon, Ramkumar
    • BMB Reports
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    • v.55 no.8
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    • pp.370-379
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    • 2022
  • Human pregnancy is a delicate and complex process where multiorgan interactions between two independent systems, the mother, and her fetus, maintain pregnancy. Intercellular interactions that can define homeostasis at the various cellular level between the two systems allow uninterrupted fetal growth and development until delivery. Interactions are needed for tissue remodeling during pregnancy at both fetal and maternal tissue layers. One of the mechanisms that help tissue remodeling is via cellular transitions where epithelial cells undergo a cyclic transition from epithelial to mesenchymal (EMT) and back from mesenchymal to epithelial (MET). Two major pregnancy-associated tissue systems that use EMT, and MET are the fetal membrane (amniochorion) amnion epithelial layer and cervical epithelial cells and will be reviewed here. EMT is often associated with localized inflammation, and it is a well-balanced process to facilitate tissue remodeling. Cyclic transition processes are important because a terminal state or the static state of EMT can cause accumulation of proinflammatory mesenchymal cells in the matrix regions of these tissues and increase localized inflammation that can cause tissue damage. Interactions that determine homeostasis are often controlled by both endocrine and paracrine mediators. Pregnancy maintenance hormone progesterone and its receptors are critical for maintaining the balance between EMT and MET. Increased intrauterine oxidative stress at term can force a static (terminal) EMT and increase inflammation that are physiologic processes that destabilize homeostasis that maintain pregnancy to promote labor and delivery of the fetus. However, conditions that can produce an untimely increase in EMT and inflammation can be pathologic. These tissue damages are often associated with adverse pregnancy complications such as preterm prelabor rupture of the membranes (pPROM) and spontaneous preterm birth (PTB). Therefore, an understanding of the biomolecular processes that maintain cyclic EMT-MET is critical to reducing the risk of pPROM and PTB. Extracellular vesicles (exosomes of 40-160 nm) that can carry various cargo are involved in cellular transitions as paracrine mediators. Exosomes can carry a variety of biomolecules as cargo. Studies specifically using exosomes from cells undergone EMT can carry a pro-inflammatory cargo and in a paracrine fashion can modify the neighboring tissue environment to cause enhancement of uterine inflammation.

Eating Habits, Eating Behaviors and Nutrition Knowledge of Higher Grade Elementary School Students in Jeonju Area (전주지역 초등학교 고학년 남.여 학생의 식습관 및 식행동, 영양지식에 관한 연구)

  • Yu, Ok-Kyeong;Park, Su-Hui;Cha, Youn-Soo
    • Journal of the Korean Society of Food Culture
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    • v.22 no.6
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    • pp.665-672
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    • 2007
  • The purpose of this study was to investigate the eating habits and eating behaviors, nutrition knowledge of students in 4, 5 and 6th graders of elementary school in Jeonju Area. The subjects for questionnaire were 2,568 elementary school students (boys 1,364, girls 1,204). The results were analyzed by SPSS program, and were as follows. In anthropometric data, there were significant differences between boys and girls. In eating habits and eating behaviors, there were significant differences in the rate of 'Hasty eating habit(p<0.01)', 'Most heavy meal(p<0.01)', 'Eating when receive stress(p<0.05)', and 'Frequency of snack eating per day(p<0.01)' between boys and girls. In total scores of nutrition knowledge, there were significant differences between boys and girls. In nutrition knowledge, there were significant differences in the rate of 'Carbohydrate and fat give heat and force.(p<0.001)', 'Carbohydrate is nutrient that make muscle and blood of our body.(p<0.01)', 'Overeating of carbohydrate does not contribute gain of weight. (p<0.05)', To intake vitamin, it is good to eat fresh fruit and vegetable.(p<0.01)', 'Calcium deficiency is leading to anemia.(p<0.001)' between boys and girls. In conclusion, systematical educational programs need to be developed at elementary school. These should include information about achieving a balanced diet, good eating habit and behavior, meal management and Korean dietary culture. Also, nutritional education at home must be emphasized.

Full-scale TBM excavation tests for rock-like materials with different uniaxial compressive strength

  • Gi-Jun Lee;Hee-Hwan Ryu;Gye-Chun Cho;Tae-Hyuk Kwon
    • Geomechanics and Engineering
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    • v.35 no.5
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    • pp.487-497
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    • 2023
  • Penetration rate (PR) and penetration depth (Pe) are crucial parameters for estimating the cost and time required in tunnel construction using tunnel boring machines (TBMs). This study focuses on investigating the impact of rock strength on PR and Pe through full-scale experiments. By conducting controlled tests on rock-like specimens, the study aims to understand the contributions of various ground parameters and machine-operating conditions to TBM excavation performance. An earth pressure balanced (EPB) TBM with a sectional diameter of 3.54 m was utilized in the experiments. The TBM excavated rocklike specimens with varying uniaxial compressive strength (UCS), while the thrust and cutterhead rotational speed were controlled. The results highlight the significance of the interplay between thrust, cutterhead speed, and rock strength (UCS) in determining Pe. In high UCS conditions exceeding 70 MPa, thrust plays a vital role in enhancing Pe as hard rock requires a greater thrust force for excavation. Conversely, in medium-to-low UCS conditions less than 50 MPa, thrust has a weak relationship with Pe, and Pe becomes directly proportional to the cutterhead rotational speed. Furthermore, a strong correlation was observed between Pe and cutterhead torque with a determination coefficient of 0.84. Based on these findings, a predictive model for Pe is proposed, incorporating thrust, TBM diameter, number of disc cutters, and UCS. This model offers a practical tool for estimating Pe in different excavation scenarios. The study presents unprecedented full-scale TBM excavation results, with well-controlled experiments, shedding light on the interplay between rock strength, TBM operational variables, and excavation performance. These insights are valuable for optimizing TBM excavation in grounds with varying strengths and operational conditions.

Free congregate site meal service systems for elderly at urban area (도시지역 노인을 위한 무료 급식시설의 급식 서어비스 현황조사)

  • Lee, Young-Mee;Lee, Ki-Wan;Myung, Choon-Ok;Park, Young-Sim;Nam, Hae-Won
    • Journal of the Korean Society of Food Culture
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    • v.14 no.4
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    • pp.431-446
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    • 1999
  • The purpose of this study is to examine current foodservice management practices at free congregate meal service for elderly people. Forty seven meal service centers as well as randomly selected Seoul and Kyunggido area were surveyed and interviewed and results were summarized as follows: The cost of each meal(lunch) was ranged from 1,300 won to 1,500 won and 68% of target centers were severed over 100 meals per day. Meal time for lunch begins from 10:30 am to 12:00 because great portion of elderly didn't take breakfast frequently. 52.3% of centers severed meal 5 times per week, just weekdays. 21.3% of centers employeed dietitian, 63.8% of center employeed cook. 95.7% of center were supported labor force by volunteers. Volunteer was important contribution to free meal service. Utilizing the labor force more effectively is thus a major challenge facing manager in each center. Ideal supporting system of free foodstuff, foodbank was still minor source of securing foodstuff. Most of centers(46 centers)served lunch, only one of them served breakfast and lunch. Government was the major financial sponsor, the second of them was religious organization. The large portions of financial support provided only food cost of total meal service budget. Most of center adapted self-service system. Standardized recipes were not developed and meal preparation was controlled under the experience of volunteers. Recording system of nutrition management, production control, storage and inventory control was not adapted by most of sites. It is suggested that in order to meet the change of the patterns of social and family structure, the service of the center should be offended in urban area and it is necessary to develop systematic management models for the center. It was suggested that not only financial support but also systematical support on management by the local government may be necessary to meet the goal of supply nutritionally balanced food at center.

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Effectiveness of clinical remounting improving balanced occlusion of complete dentures (총의치 균형교합에 영향을 미치는 진료실재부착의 효과)

  • Lee, Ye-Jin;Kim, Jong-Hoi;Ko, Kyung-Ho;Huh, Yoon-Hyuk;Park, Chan-Jin;Cho, Lee-Ra
    • The Journal of Korean Academy of Prosthodontics
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    • v.58 no.4
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    • pp.328-334
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    • 2020
  • Clinical remounting of complete denture is performed to refine occlusal harmony in maxillo-mandibular relation. It has been reported that patients who used adjusted dentures with clinical remounting felt less complications such as pain and discomfort in mastication. The purpose of this study was to assess effects of clinical remounting with case series. Seven patients with existing complete prosthesis were included. Clinical remounting procedure was done through interocclusal relation recording. In addition, occlusal force was measured with pressure indicating sensor and occlusal contact areas were evaluated with photo occlusion analysis. Occlusal contact areas of prosthesis were enlarged, while bite pressure was not increased. Hit and slide phenomenon of prosthesis was reduced concurrently. Clinical remounting procedure improved denture stability and increased occlusal contact area. Therefore, clinical remounting should be considered.