• Title/Summary/Keyword: positions

Search Result 6,435, Processing Time 0.033 seconds

The optimal paremeter design of rapid thermal processing to improve wafer temperature uniformity on the semiconductor manufacturing (반도체 공정에서 웨이퍼의 온도균일도향상을 위한 고속열처리공정기의 최적 파라미터 설계)

  • 최성규;최진영;권욱현
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.1508-1511
    • /
    • 1997
  • In this paper, design parameters of Rapid Thermal Processing(RrW) to minimize the wafer tempera ture uniformity errors are proposed. 1,anip ling positions and the wafer height are important parameters for waf er temperature uniformity in R'I'P. We propose the method to seek lamp ling positions and the wafer height for optimal temperature uniformity. l'he ~~roposed method is applied to seek optimal lamp ling positions and the waf er height of 8 inch wafer. 'I'o seek the optimal lamp ling positions and the wafer height, we var\ulcorner. lamp ling 110s itions and the wafer height and then formulate the wafer temperature uniformity problem to the linear programmi ng problem. Finally, it is shown that the wafer temperature uniformity in RI'I' designed by optimal prarneters is improved to comparing with Ii'l'P designed by the other method.

  • PDF

Prediction of Heating-line Positions for Line Heating Process by Using a Neural Network (신경회로망을 이용한 선상가열공정의 가열선 위치선정에 관한 연구)

  • 손광재;양영수;배강열
    • Journal of Welding and Joining
    • /
    • v.21 no.4
    • /
    • pp.31-38
    • /
    • 2003
  • Line heating is an effective and economical process for forming flat metal plates into three-dimensional shapes for plating of ships. Because the nature of the line heating process is a transient thermal process, followed by a thermo elastic plastic stress field, predicting deformed shapes of plate is very difficult and complex problem. In this paper, neural network model o3r solving the inverse problem of metal forming is proposed. The backpropagation neural network systems for determining line-heating positions from object shape of plate are reported in this paper. Two cases of the network are constructed-the first case has 18 lines which have different positions and directions and the second case has 10 parallel heating lines. The input data are vertical displacements of plate and the output data are selected heating lines. The train sets of neural network are obtained by using an analytical solution that predicts plate deformations in line heating process. This method shows the feasibility that the neural network can be used to determine the heating-line positions in line heating process.

A Study on Hydrodynamic Coefficient Characteristics of Air Bearing for High Speed Journal

  • Lee, Jong-Ryul;Lee, Deug-Woo;Soeng, Sueng-Hak;Lee, Yong-Chul
    • KSTLE International Journal
    • /
    • v.4 no.2
    • /
    • pp.66-72
    • /
    • 2003
  • This paper presents the hydrodynamic effect by the journal speed, eccentricity and source positions in order to overcome the defects of air bearing such as low stiffness and damping coefficient. Choosing the two row source position of air bearing is different from existing investigations in the side of pressure distribution of air film because of the high speed of journal and the wedge effects by the eccentricity. These optimal choices of the two row source positions enable us to improve the performance of the film reaction force and loading force as making the high-speed spindle. In this paper, The pressure behavior in theory of air film in high speed region of journal according to the eccentricity of journal and the source positions analyzed. The theoretical analysis has been identified by experiments. The results of investigated characteristics may be applied to precision devices like ultra-precision grinding machine and ultra high-speed milling.

A Study of Pause Positions in Korean Students' English Reading (끊어 읽기 오류 분석을 통한 영어 읽기 지도 방안 연구)

  • Lee, Jin-Mi;Park, Han-Sang
    • Proceedings of the KSPS conference
    • /
    • 2007.05a
    • /
    • pp.95-98
    • /
    • 2007
  • This study investigates pause positions of Korean students' reading of an English script. 12 natives speakers of English and 18 Korean students were asked to read The North Wind and the Sun. The common pause positions were determined by examining the pauses of the native speakers' readings. Korean students were asked to mark pauses on a script. And then they were trained to put pauses as native speakers of English do. Although some errors have been corrected after the training, others have not been corrected in Korean students' readings. Korean students made fewer errors in marking on the script than in reading the script. They seem to know where to put pauses, but lack of practice makes it difficult to put pause in the right positions when they read. That suggests that teachers should continue to teach students where to put pauses in their reading or speaking English.

  • PDF

3-Dimensional Sensor Array Shape Calibration in Near Field Environment (근거리 환경에서의 3차원 배열센서 형상 보정 기법)

  • Ryu, Chang-Soo;Eoh, Soo-Hae;Kang, Hyun-Koo;Rhyoo, Sang-Wook
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.6 no.4
    • /
    • pp.361-366
    • /
    • 2003
  • Most sensor array signal processing methods for multiple source localization require knowledge of the correct shape of array(the correct positions of sensors that consist array), because sensor position uncertainty can severely degrade the performance of array signal processing. In particular, it is assumed that the correct positions of the sensors are known, but the known positions may not represent the true sensor positions. Various algorithms have been proposed for 2-D sensor array shape calibration in far field environment. However, they are not available in near field. In this paper, 3-D sensor array shape calibration algorithm is proposed, which is available in near field.

  • PDF

Design and control of quiet zone (principle and example) (조용한 공간 만들기 (방법론과 예))

  • Kim, Yang-Han;Yun, Du-Byeong;Nam, Gyeong-Uk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2000.06a
    • /
    • pp.565-570
    • /
    • 2000
  • In order to make a quiet zone, one can consider methods to generate a secondary sound field that cancels a primary sound field. Active noise control (ANC) is one of the kinds. This paper mainly deals with the issues on determining the optimal positions of control sources and sensors for making a desired quiet zone. The issues address the reason why the positions are important, how the positions are optimized, and what the measure on the optimal positions is in an uncertain sound field. It is also shown that a power control is applicable to a specific uncertain sound field. In addition, this paper shows that a control material method, which passively changes a boundary condition, is essentially found to be on the same road of ANC.

  • PDF

Weak Connectivity in (Un)bounded Dependency Constructions

  • Kim, Yong-Beom
    • Proceedings of the Korean Society for Language and Information Conference
    • /
    • 2007.11a
    • /
    • pp.234-240
    • /
    • 2007
  • This paper argues that various kinds of displaced structures in English should be licensed by a more explicitly formulated type of rule schema in order to deal with what is called weak connectivity in English. This paper claims that the filler and the gap site cannot maintain the total identity of features but a partial overlap since the two positions need to obey the structural forces that come from occupying respective positions. One such case is the missing object construction where the subject fillers and the object gaps are to observe requirements that are imposed on the respective positions. Others include passive constructions and topicalized structures. In this paper, it is argued that the feature discrepancy comes from the different syntactic positions in which the fillers are assumed to be located before and after displacement. In order to capture this type of mismatch, syntactically relevant features are handled separately from the semantically motivated features in order to deal with the syntactically imposed requirements.

  • PDF

Effects of VHP Positions on the Steering Stability of Agricultural Tractors(I) -Experimental Verification of Safe VHP Positions- (가상(假想) 히치점의 위치(位置)가 트랙터의 조향(操向) 안정성(安定性)에 미치는 영향(影響)(I) -가상(假想) 히치점의 안전(安全) 영역(領域)에 대한 실험적(實驗的) 고찰(考察)-)

  • Shin, S.I.;Kim, K.U.
    • Journal of Biosystems Engineering
    • /
    • v.16 no.3
    • /
    • pp.219-227
    • /
    • 1991
  • This paper concerns with experimental verification of the theory on the safe VHP positions presented in the first part of this study. In the experiment, tillage operation was conducted using a plow mounted to the threepoint hitch and the forces acting on the hitch points were measured. Using the data from the test tractor and plow, computer simualtion was also conducted and its results were compared with those obtained from the field experiment. The comparison showed a reasonable agreement between the two results, by which the theoretical method for the determination of safe VHP positions for steering control can be verified. Some guidelines for expanding the safe VHP region were finally proposed.

  • PDF

Phonetic Realizations of English Word Stress in Utterances (실제 상황에서 발화된 영어 단어 강세의 음성 실현)

  • Kim, He-Kyung;Kim, Soo-Jung
    • Speech Sciences
    • /
    • v.13 no.4
    • /
    • pp.89-105
    • /
    • 2006
  • This study examines the phonetic realizations of English word stress to identify the influence of experiment method on experiment results. Stimuli uttered by native and Korean ESL beginners in authentic conversations are extracted to be shuffled according to their positions in utterances and information structure. Results indicate that the acoustic characteristics of English word stress are realized depending on its position in utterances. The native speakers correlate the stressed syllables in shorter duration with higher pitch and stronger intensity at sentence-final positions unlike the previous experiments and the traditional definition that stressed syllables are uttered in longer duration with higher pitch and stronger intensity; at sentence-medial positions, the native speakers correlate the stressed syllables in longer duration with higher pitch and no regularity in intensity or in shorter duration with lower pitch and intensity depending on their conversational intention. Korean ESL beginners correlate the stressed syllables in shorter duration regardless of positions in sentences with no regularity in pitch and intensity. This study, thus, shows that a different experiment method may result in different results on the phonetic realizations of English word stress.

  • PDF

A Comparison of Vital Capacity Value With Spinal Cord Injury Following Changing Positions (척수손상 환자의 자세에 따른 폐활량의 변화)

  • Kim, Young-Rok;Lee, Jeong-Weon
    • Physical Therapy Korea
    • /
    • v.5 no.3
    • /
    • pp.48-55
    • /
    • 1998
  • The purpose of this study was to identify vital capacity (VC) in relation to the changing position of 19 patients with spinal cord injury (SCI) and 20 normal controls. Among the 19 SCI patients, there were 9 quadriplegics and 10 paraplegics. The vital capacity was measured in each subject during sitting, standing, lying, and head down position of 30 degrees. The data were analysed by the Kruskal-Wallis test, Mann-Whitney test, and Wilcoxon signed rank test. For the SCI, significant difference of VC accoring to the 4 positions between quadriplegics and paraplegics. In the control group, significant difference of VC according to the 4 positions. In 4 positions the VC of men were significantly larger than that of women between two groups. No statistical significant difference was shown in VC by the postural change between quadriplegics and paraplegics.

  • PDF