• Title/Summary/Keyword: Transition pattern

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Effect of the Gravity Forces on Flow Pattern and Frictional Pressure Drop in Two-Phase, Two-Component Flow

  • Choi, B.-H;Han, W.-H
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.2
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    • pp.338-346
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    • 2004
  • Experimental data on the effect of the variable gravity magnitude, namely microgravity, normal gravity and hyper-gravity, on flow pattern and frictional pressure drop were obtained during co-current air-water flow in a horizontal tube, The flow patterns were found to depend strongly on the gravity magnitude and certain flow pattern were found to depend on the gas superficial velocity. The effect of the gravity magnitude had an effect on the frictional pressure drop only at low flow rates. The present data are used to evaluate some of existing flow pattern transition and pressure drop models and correlations.

Predicting Longitudinal Patterns of Emotional and Behavioral Problems in Early Adolescence : A Latent Class and Latent Transition Analysis (초기 청소년기 정서행동문제의 종단적 변화에 따른 잠재프로파일 분류 및 전이 영향요인 분석)

  • Kim, Bitna;Jang, Hyein;Park, Ju Hee
    • Human Ecology Research
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    • v.60 no.1
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    • pp.53-68
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    • 2022
  • Using a person-centered approach, the current study investigated latent profiles for the emotional and behavioral problems of students in sixth-grade in elementary school and second grade of middle school. The aim was to explore latent transition patterns and verify the factors affecting the transitions. The participants were 1,937 adolescents who responded to the 3rd year (6th grade of elementary school; Time 1), 4th year (1st grade of middle school), and 5th year (2nd grade of middle school; Time 2) of the Korean Children Youth Panel Study. Latent profile and latent transition analyses were performed. The results were as follows: first, the latent profile of emotional and behavioral problems changed from Time 1 to Time 2. The latent groups at Time 1 were classified into low, moderate, high, and externalizing-dominant, whereas at Time 2, five groups were identified: low, moderate, high, externalizing-dominant, and withdrawal-dominant. Second, transition analyses revealed that although 22.3-57.0% of latent groups remained unchanged, there were significant changes over time between groups, as a new group ('withdrawal-dominant') emerged in Time 2. Third, different factors influenced the latent profile transition of emotional and behavioral problems depending on the transition pattern. Higher levels of self-esteem, better relationships with peers and teachers, and lower levels of parental inconsistency meant emotional and behavioral problems had not worsened at Time 2. The results suggest that early interventions are needed during the transition from childhood to early adolescence.

Design and implementation of improved march test algorithm for embedded meories (내장된 메모리를 위한 향상된 March 테스트 알고리듬의 설계 및 구현)

  • Park, Gang-Min;Chang, Hoon;Yang, Seung-Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.7
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    • pp.1394-1402
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    • 1997
  • In this work, an efficient test algorithm and BIST architeture a for embedded memories are presented. The proposed test algorithm can fully detect stuck-at fault, transition fault, coupling fault. Moreover, the proposed test algorithm can detect nighborhood pattern sensitive fault which could not be detected in previous march test algoarithms. The proposed test algorithm perposed test algorithm performs testing for neghborhood pattern sensitive fault using backgroung data which has been used word-oriented memory testing.

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Molecular Dynamics Study on the Effect of Process Parameters on Nanoimprint Lithography Process (공정인자들이 나노임프린트 리소그래피 공정에 미치는 영향에 대한 분자동역학 연구)

  • Kang, Ji-Hoon;Kim, Kwang-Seop;Kim, Kyung-Woong
    • Tribology and Lubricants
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    • v.22 no.5
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    • pp.243-251
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    • 2006
  • Molecular dynamics simulations of nanoimprint lithography NIL) are performed in order to investigate effects of process parameters, such as stamp shape, imprinting temperature and adhesive energy, on nanoimprint lithography process and pattern transfer. The simulation model consists of an amorphous $SiO_{2}$ stamp with line pattern, an amorphous poly-(methylmethacrylate) (PMMA) film and an Si substrate under periodic boundary condition in horizontal direction to represent a real NIL process imprinting long line patterns. The pattern transfer behavior and its related phenomena are investigated by analyzing polymer deformation characteristics, stress distribution and imprinting force. In addition, their dependency on the process parameters are also discussed by varying stamp pattern shapes, adhesive energy between stamp and polymer film, and imprinting temperature. Simulation results indicate that triangular pattern has advantages of low imprinting force, small elastic recovery after separation, and low pattern failure. Adhesive energy between surface is found to be critical to successful pattern transfer without pattern failure. Finally, high imprinting temperature above glass transition temperature reduces the imprinting force.

Analysis of Pattern on the Japanese Kosode (일본 소수(小岫)에 나타난 문양분석)

  • Park, Ok-Lyon;Lee, Hang-Hwa
    • Fashion & Textile Research Journal
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    • v.1 no.1
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    • pp.62-68
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    • 1999
  • The study has examined about the origin and change of traditional Japanese dress "Kosode" and classified it according to its ages and also classified its patterns which appeared on the Kosode by its kinds, and divide the patterns with constituent method and expressional method and so, studied and analyzed them with type of patterns according to the change of the times. The result of research were as follows: 1. Subject of patterns that appeared on the Kosode was used with mainly plant pattern, animals pattern, pictorial pattern, artificial pattern, and abstract patterns. 2. Expressional method of this patterns was mostly expressed simply with tie dyeing in ancient times, but it changed complex its expressional method and diversely due to the development of common's culture as time goes on. 3. For the arrangement of its pattern were arranged regularly mostly make demarcate and though they are as if seemed dispersed, but a characteristic that can find regulations in it. 4. Transition of patterns that appeared on the Kosode it developed at the beginning of ancient syouboon, Katasuso pattern and Katamigaori patterns at the samurai's society in the medieval society and developed to Koicho kosode and Kambun kosode in modern times.

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NUMERICAL STUDY ON FLOW CHARACTERISTIC IN THE HEAT RECOVERY STEAM GENERATOR (배열회수장치의 유동특성에 관한 수치적 연구)

  • Choi, H.K.;Yoo, G.J.;Shin, B.J.;Kim, C.H.
    • Journal of computational fluids engineering
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    • v.15 no.1
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    • pp.17-23
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    • 2010
  • Performance improvements of the heat recovery steam generator(HRSG) can be achieved by improving the flow distribution of exhaust gases for a various type of different equipments. A number of design parameters are systematically investigated and their effects on an index of velocity deviation established. The parameters include the three shape of the transition duct and the wide range of the guide vane angles. The numerical results clearly reveal feature of the flow pattern in the transition duct, velocity deviation and pressure drop at tube bank part.

Growth Pattern of Pandalus gracilis (Decapoda: Pandalidae) in the Southern Coastal Waters of Korea

  • Oh, Chul-Woong
    • Fisheries and Aquatic Sciences
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    • v.14 no.2
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    • pp.111-117
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    • 2011
  • The population dynamics of Pandalus gracilis was investigated in the southeastern coastal area of Korea between May 1998 and April 2000. Of the 4,127 specimens, 57% were identified as females, 39% as males, and 4% as transitional hermaphrodites. The number of females was greater than that of males and transexuals. A significant correlation was observed between the number of transitional hermaphrodites and ambient seawater temperature. Growth parameters were estimated using the modified von Bertalanffy growth function model incorporating seasonal variation in growth using the program ELEFAN. Females grew faster and reached a larger size-at-age than males (K=0.65/y and $L_{\infty}$=17.86 mm carapace length [CL] for females; K=0.51/y and $L_{\infty}$=14.70 mm CL for males). Mean size and age (95% confidence limits) at sex transition, calculated from growth parameters, were 7.07 mm carapace length and 1.05 years, respectively. The reproductive strategies of pandalid shrimps are discussed in terms of the type of sex transition.

A Study on Two-Phase Flow Pattern of Pure Refrigerants R134a and Rl23 and Zeotropic Mixture R134a/R123 in Horizontal Tubular (R134a 및 Rl23과 비공비 혼합냉매 R134a/R123의 수평관내 이상유동양식에 관한 연구)

  • Lim, Tae-Woo;Kim, Jun-Hyo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.8
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    • pp.1033-1041
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    • 2003
  • Two-phase flow pattern data during horizontal in-tube flow boiling are presented for pure and mixed refrigerants of R134a and Rl23, The flow pattern is observed through tubular sight glasses located at inlet and outlet of the test section, which is made of a stainless steel tube, 2m long with 10mm I.D., 1.5mm wall thickness. The obtained results are compared with the available various correlations for flow pattern. The flow pattern map of Hashizume was in good agreement with the present data except the region of low mass velocity. Weisman flow pattern map was also known to satisfactorily predict data for refrigerants in the region of annular flow. In this study, the flow pattern are simply classified into two groups; stratified(including intermittent, stratified and stratified-wavy) flow and annular flow. The transition quality from stratified to annular flow was obtained by modifying the liquid Froude number.

Hangeul Character Classification Model Based on Cognitive Theory and ART Neural Network (인지이론과 ART 신경회로망에 기반한 한글 문자 분류 모델)

  • Park Joong-Yang;Park Jae-Heung;Jang Jae-Hyuk
    • The Journal of the Korea Contents Association
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    • v.5 no.5
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    • pp.33-42
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    • 2005
  • In this paper, we propose a new training algorithm for improving pattern classification performance of ART neural network. The proposed train algorithm restricts unnecessary cluster generation and transition, applies the location extraction algorithm, and operates the reset system based on the agreement between the present learning pattern and the initial pattern. As a result, repetitive input of a pattern does not generate a new cluster and mis-recognition rate decreases.

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Modifiable Walking Pattern Generation Handling Infeasible Navigational Commands for Humanoid Robots

  • Lee, Bum-Joo;Kim, Kab Il
    • Journal of Electrical Engineering and Technology
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    • v.9 no.1
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    • pp.344-351
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    • 2014
  • In order to accomplish complex navigational commands, humanoid robot should be able to modify its walking period, step length and direction independently. In this paper, a novel walking pattern generation algorithm is proposed to satisfy these requirements. Modification of the walking pattern can be considered as a transition between two periodic walking patterns, which follows each navigational command. By assuming the robot as a linear inverted pendulum, the equations of motion between ZMP(Zero Moment Point) and CM(Center of Mass) state is easily derived and analyzed. After navigational command is translated into the desired CM state, corresponding CM motion is generated to achieve the desired state by using simple ZMP functions. Moreover, when the command is not feasible, feasible command is alternated by using binary search algorithm. Subsequently, corresponding CM motion is generated. The effectiveness of the proposed algorithm is verified by computer simulation.