• 제목/요약/키워드: backward

검색결과 2,439건 처리시간 0.03초

Tongue-Lip Adhesion Using an Alveolar Protector Appliance for Management of Pierre Robin Sequence (피에르 로빈 연속증의 치료로써 치조 보호 장치를 이용한 혀-하순 유착술)

  • Lee, Jang-Won;Park, Beyoung-Yun
    • Archives of Plastic Surgery
    • /
    • 제38권4호
    • /
    • pp.547-551
    • /
    • 2011
  • Purpose: Pierre Robin sequence is a congenital malformation in which micrognathia causes glossoptosis and airway obstruction. If conservative treatment fails, surgical procedures such as tongue-lip adhesion can be performed. However, this procedure remains a subject of debate, with favorable results being countered by reports of complications. To overcome the above limitations, we revised the traditional method of tongue-lip adhesion using an alveolar protector. Methods: Between 1992 and 2011, a total of eight patients were identified with Pierre Robin sequence and were treated with tongue-lip adhesion. Two of these eight tongue-lip adhesion procedures were performed with an alveolar protector. The operative technique for tongue-lip adhesion was similar to that described in other published reports. The alveolar protector was inserted between the ventral surface of the tip of the tongue and the lower labial sulcus. Results: Tongue-lip adhesion failed in two patients because of wound dehiscence. The primary surgical success rate was 66.7%. In the two tongue-lip adhesion procedures performed with the alveolar protector, we observed no postoperative complications. Conclusion: Resistance to traction of the tongue can be encountered with nonunionized symphysis menti, causing loosening of the traction suture through the symphysis menti. This can lead to backward positioning of tongue, resulting in dehiscence of tongue lip adhesion. The alveolar protector is a good adjunct to tongue-lip adhesion because this method avoids postoperative loosening of the traction suture and wound dehiscence. It is a simple and effective auxiliary method that yields functional improvement.

The Effect of Swirl Intensity on Flow and Combustion Characteristics of Flat Flame Burner (선회도가 평면화염버너의 유동과 연소 특성에 미치는 영향)

  • Jeong, Yong-Gi;Kim, Gyeong-Cheon;Jeon, Chung-Hwan;Jang, Yeong-Jun
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • 제26권2호
    • /
    • pp.336-344
    • /
    • 2002
  • In this study, the flow and combustion characteristics of flat flame burner with twirler were investigated. There are several factors that define the characteristics of burner. Among them, the experiments was focused on swirl effect by four types of twirler in terms of flow structure, distribution of temperature and emission characteristics. In PIV(Particle Image Velocimetry) experiment, the less of swirl number, axial flow is dominant at the center. As swirl number increases, the flow develops along the burner tile and backward flow becomes stronger at center. From the combustion characteristics, as long as combustion load increases, blow-off limit was improved. But at the higher swirl number, the limit is decreased. At swirl number 0, the temperature is shown typical distribution of long flame burner. but swirl number increases, the temperature distribution is uniform in front of round tile. Therefore, the temperature distribution is coincided with flow structure. As excess air ratio increases, NO concentrations are high. But high swirl number gives rise to become low NO concentrations. The flame characteristics are comprised in wrinkled laminar-flame regime according to turbulence Reynolds number(Rel) and Damkohler number(Da).

A Relative for Finite Element Nonlinear Structural Analysis (상대절점좌표를 이용한 비선형 유한요소해석법)

  • Kang, Ki-Rang;Cho, Heui-Je;Bae, Dae-Sung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 한국소음진동공학회 2005년도 추계학술대회논문집
    • /
    • pp.788-791
    • /
    • 2005
  • Nodal displacements are referred to the Initial configuration in the total Lagrangian formulation and to the last converged configuration in the updated Lagrangian formulation. This research proposes a relative nodal displacement method to represent the position and orientation for a node in truss structures. Since the proposed method measures the relative nodal displacements relative to its adjacent nodal reference frame, they are still small for a truss structure undergoing large deformations for the small size elements. As a consequence, element formulations developed under the small deformation assumption are still valid fer structures undergoing large deformations, which significantly simplifies the equations of equilibrium. A structural system is represented by a graph to systematically develop the governing equations of equilibrium for general systems. A node and an element are represented by a node and an edge in graph representation, respectively. Closed loops are opened to form a spanning tree by cutting edges. Two computational sequences are defined in the graph representation. One is the forward path sequence that is used to recover the Cartesian nodal displacements from relative nodal displacements and traverses a graph from the base node towards the terminal nodes. The other is the backward path sequence that is used to recover the nodal forces in the relative coordinate system from the known nodal forces in the absolute coordinate system and traverses from the terminal nodes towards the base node. One closed loop structure undergoing large deformations is analyzed to demonstrate the efficiency and validity of the proposed method.

  • PDF

Acoustical Estimation of Zooplankton Distributions From the Backscattered Signal of the Acoustic Doppler Current Profiler in the Korea Strait (한국 해협에서 ADCP(Acoustic Doppler Current Profiler)의 음파 산란신호에 의한 동물플랑크톤 분포의 추정)

  • Na, Jung Yul;Park, Joung Soo
    • 한국해양학회지
    • /
    • 제24권4호
    • /
    • pp.172-183
    • /
    • 1989
  • Acoustical estimation of vertical distributions of zooplankton was carried out by using the backscattered signals of ADCP which was deployed in the Korea Strait in September, 1978. the backscattered signals of ADCP represents the total backward sound intensity caused by the scatters existing within the insonified water column of 8m deep. Based on these backscattered intensities, the estimated number of individual zooplankton (namely, Copepods) varies with depth such that in the surface layer above the thermocline, the numbers are exceedingly larger than the lower layer. It is also shown that a relatively larger number of individuals exists in the bottom cold water layer in the centeral part of the Strait. The horizontal distribution of the zooplankton in the surface layer across the west channel of the Strait shows that the number is higher in the coastal zone of the Korea and it decreases toward the central and then remains constant up to the vicinity of the Tsushima Island where it increases again. This type of distributions is well fitted to the one obtained at several stations by the conventional method at least in qualitative way. Therefore, it is quite plausible to use the ADCP data for monitoring the spatial and temporal distributions of zooplankton.

  • PDF

Behaviour Studies of Red Till Fish, Branchiostegus Japonicus to a Longline Gear for Hook Design (연승어구에 대한 옥돔의 행동과 낚시형상 설계)

  • Lee, Chun-Woo;Park, Seong-Wook
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • 제31권3호
    • /
    • pp.240-246
    • /
    • 1995
  • The responses of red tile fish, Branchiostegus Japonicus to a longline gear were examined in an experimental tank using two video cameras, in order to know hooking mechanism and improve longline hook. In attraction stage, the fish swim to upstream direction slowly just above the bottom toward the baited hook. The majority of the fish then biting the bait incompletely, after the biting, the fish made a backward swimming with low intense, and the bait was usually spitting out when snood was stretched. In most case, hooking took place at the moment the fish made jerk or rush after the bait wallowed. The behaviour sequence closely related to hooking are chewing and jerking or chewing and rushing. According to the field experiments, the tested hooks of long shank show very low catching efficiency compared to the traditional hook with short shank, and the hooked position of the traditional hooks were oesophagus or stomach but the tested hooks were mouth in the most cases. For catching efficiency, desirable hook shape were inferenced inner-curved point and short shank because its ease to swallow. The shape and demensions of a porposed hook were determined in consideration of mechanized gear handling and hooking performance.

  • PDF

Systolic Array Simulator Construction for the Back-propagation ANN (역전파 ANN의 시스톨릭 어레이를 위한 시뮬레이터 개발)

  • 박기현;전상윤
    • Journal of Korea Society of Industrial Information Systems
    • /
    • 제5권3호
    • /
    • pp.117-124
    • /
    • 2000
  • A systolic array is a parallel processing system which consists of processing elements of basic computation capabilities, connected with regular and local communication lines. It has been known that a systolic array is on of effective systems to solve complicated communication problems occurred between densely connected neurons on ANN(Artificial Neural Network). In this paper, a systolic array simulator for the back-propagation ANN, which automatically constructs the proper systolic array for a given number of neurons of the ANN, is designed and constructed. With animation techniques of the simulators, it is easy for users to be able to examine the execution of the back-propagation algorithm on the designed systolic array step by step. Moreover the simulator can perform forward and backward operations of the back-propagation algorithm either in sequence or in parallel on the designed systolic array. Parallel execution can be performed by feeding continuous input patterns and by executing bidirectional propagations on all of processing elements of a systolic array at the same time.

  • PDF

A Study on Implementation of Special-Purpose Manipulator for Home Service Robot (홈 서비스 로봇을 위한 전용 머니퓰레이터의 구현에 관한 연구)

  • Kim, Seung-Woo;Kim, Hi-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • 제12권11호
    • /
    • pp.5219-5226
    • /
    • 2011
  • A specialized anthropomorphic robot manipulator which can be attached to the housemaid robot McBot II, is developed In this paper. This built-in type manipulator consists of both arms with 3 DOF (Degree of Freedom) each and both hands with 3 DOF each. The robotic arm is optimally designed to satisfy both the minimum mechanical size and the maximum workspace. Minimum mass and length are required for the built-in cooperated-arms system. But that makes the workspace so small. This paper proposes optimal design method to overcome the problem by using neck joint to move the arms horizontally forward/backward and waist joint to move them vertically up/down. The robotic hand, which has two fingers and a thumb, is also optimally designed in task-based concept. Finally, the good performance of the developed manipulator is confirmed through live test of tasks.

Reduction of Economic Disparities in the Regions of Kazakhstan Based on Inclusive Development

  • NURLANOVA, Nailya K.;SATYBALDIN, Azimkhan A.;BRIMBETOVA, Nursaule Zh.;KIREYEVA, Anel A.
    • The Journal of Asian Finance, Economics and Business
    • /
    • 제6권2호
    • /
    • pp.299-307
    • /
    • 2019
  • This study aims to explore the theoretical concepts of inclusive development in relation to the spatial context, assessment the disparities in the social and economic development of the regions of Kazakhstan and substantiate the main mechanisms for overcoming them. In this research, authors propose the methodological tools for presenting a standard form of evaluation of social and economic development in the regions of Kazakhstan. In this study used methods, which based on measuring disproportions between the levels of economic and social development of the regions, as well as disproportions between the republican and regional levels. According to the author's methodological approach, complex and integral indexes have calculated over the period 2012-2017 for a number of indicators adapted to the conditions of Kazakhstan. The calculated indexes proposed to use as instruments for measuring the level of the social and economic development. In addition, according the obtained indexes and the results of their ranking can be the basis for the development of regional programs and management decisions. This will improve the targeted support of the population in backward regions in order to ensure inclusive development and improve the quality of life of the population.

Effect of archwire stiffness and friction on maxillary posterior segment displacement during anterior segment retraction: A three-dimensional finite element analysis

  • Park, Choon-Soo;Yu, Hyung-Seog;Cha, Jung-Yul;Mo, Sung-Seo;Lee, Kee-Joon
    • The korean journal of orthodontics
    • /
    • 제49권6호
    • /
    • pp.393-403
    • /
    • 2019
  • Objective: Sliding mechanics using orthodontic miniscrews is widely used to stabilize the anchorage during extraction space closure. However, previous studies have reported that both posterior segment displacement and anterior segment displacement are possible, depending on the mechanical properties of the archwire. The present study aimed to investigate the effect of archwire stiffness and friction change on the displacement pattern of the maxillary posterior segment during anterior segment retraction with orthodontic miniscrews in sliding mechanics. Methods: A three-dimensional finite element model was constructed. The retraction point was set at the archwire level between the lateral incisor and canine, and the orthodontic miniscrew was located at a height of 8 mm from the archwire between the second premolar and first molar. Archwire stiffness was simulated with rectangular stainless steel wires and a rigid body was used as a control. Various friction levels were set for the surface contact model. Displacement patterns for the posterior and anterior segments were compared between the conditions. Results: Both the anterior and posterior segments exhibited backward rotation, regardless of archwire stiffness or friction. Among the conditions tested in this study, the least undesirable rotation was found with low archwire stiffness and low friction. Conclusions: Posterior segment displacement may be unavoidable but reducing the stiffness and friction of the main archwire may minimize unwanted rotations during extraction space closure.

Assessment of applying rainfall forecast correction by using backward tracking method (역추적 기법을 활용한 예측강우 보정기법의 적용 및 평가)

  • Na, Wooyoung;Kang, Minseok;Kim, Gildo;Park, Junpyo;Yoo, Chulsang
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 한국수자원학회 2018년도 학술발표회
    • /
    • pp.98-98
    • /
    • 2018
  • 최근 기후변화로 인해 대류성 집중호우가 빈번하게 발생하고 있으며 이러한 강우 특성은 산지 지역에 위치한 소하천유역에 상당한 피해를 야기한다. 통상 대류성 집중호우는 규모가 작고 속도가 빠르기 때문에 중규모 이상의 유역에서 부분적으로 상이한 강우특성을 보인다. 아울러 이러한 호우 패턴의 변화는 일시적인 현상이 아닌 하나의 기상 특성으로 자리를 잡아가고 있기 때문에 이에 대한 대책마련이 더욱 필요한 실정이다. 초단기예보 모형은 돌발홍수 예경보시스템의 입력 값인 예측강우 자료를 생산한다. 시스템에 입력되는 예측강우 자료는 두 가지의 문제점을 가지게 된다. 첫 번째는 예측강우 자료 자체가 가지는 정확도의 문제이다. 이를 해결하기 위해 우리나라에서는 G/R비 개념을 도입하여 예측강우의 품질을 개선하고 있다. 두 번째 문제는 호우사상의 크기에 대한 것이다. 현재 돌발홍수 예경보시스템의 예측강우 보정기법은 호우의 거동 특성을 고려하지 않으며, 이로 인해 예측강우의 편의보정계수인 G/R비가 적절하지 않게 결정되는 문제가 발생한다. 본 연구에서는 이러한 문제점을 극복하기 위해 현재의 예측강우 보정기법과는 달리 호우의 이동경로를 고려하여 G/R비를 결정하고 이를 예측강우에 적용하는 방법을 제시하였다. 현재 호우가 위치하는 지역에 대해 G/R비를 산정하고 몇 시간 내에 대상지역에 도달하게 될 호우에 대한 예측 강우에 적용하였다. 본 연구에서는 2016년에 발생한 주요 호우사상을 선정하고, 우리나라 전역에 걸쳐 개선된 보정기법 방법론을 적용하였다. 그 결과 현재의 보정방법을 적용하는 경우 비정상적으로 과대하게 보정된 결과를 주는 데 반해, 호우의 이동경로를 고려한 보정방법을 적용한 경우에서는 실제 관측된 강우와 매우 유사한 합리적인 보정치를 제공해 주는 것으로 확인되었다.

  • PDF