• Title/Summary/Keyword: Preliminary study

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Preliminary Form Design of Cable Structure using Computer Graphics (컴퓨터 그래픽스를 이용한 케이블 구조의 초기형태 설계)

  • Kim, Nam-Hee;Koh, Hyun-Moo;Hong, Sung-Gul
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.4
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    • pp.375-382
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    • 2011
  • Nowadays computer graphic softwares have opened a lot of potential by providing parametric modeling and generative algorithms which are useful not only to describe various geometrical shapes but also to implement a designer's intent in terms of modules systematically. This study has proposed a way of developing a module for generating preliminary structural configuration using such potential computer graphics. Especially parametric modeling and generative algorithm are utilized to define various design alternatives, and moreover use of dynamic graphics enables designers to generate a structural form on one side and a force flow diagram correspondingly provided on the other. This ultimately leads to rational preliminary design of a structural form considering its force flow.

Timing of Earnings Announcement and Post-Earnings-Announcement-Drift(PEAD) (이익 공시시점과 주가지연반응)

  • Kim, Hyung-Soon
    • Asia-Pacific Journal of Business
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    • v.9 no.4
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    • pp.137-155
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    • 2018
  • It has been reported that there is a significant positive relationship between the unexpected earnings on the earnings announcement date and the cumulative abnormal returns following the earnings announcement date. This study investigates whether the results of prior studies are because the public announcement of shareholders' meeting date was selected as the event date instead of either the preliminary earnings disclosure date or the profit/loss change announcement date. The results of this study are as follows. First, post-earnings-announcement drift(PEAD) occurs when unexpected earnings were computed based on the prior period earnings and the public announcement of the shareholders' meeting date as the profit disclosure date. Second, when analyzing the PEAD with the unexpected earnings calculated using the financial analysts' forecasts, no PEAD has been found both on the date of the shareholders' meeting and the earlier date of the preliminary earnings disclosure, profit/loss change announcement, or the public announcement of the shareholders' meeting. Foster et al. (1984) analyze the PEAD using time series model and earnings forecasting model and suggest that the PEAD appears only in the time series model. In this study, too, in the case of using analysts' profit forecasts, the lack of the PEAD shows that the PEAD can be changed according to the method of measuring the unexpected earnings.

Development of a scale for the selection criteria of wedding planners (웨딩플래너 선택속성에 관한 척도 개발)

  • Kim, Ha Jeong;Yu, Jihun
    • The Research Journal of the Costume Culture
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    • v.27 no.4
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    • pp.323-335
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    • 2019
  • Identifying the selection criteria of wedding planners, who are the main human resource that contribute to the overall satisfaction level of a wedding's preparation, can produce important data for the wedding industry as it faces a transition period. To develop a scale for wedding planner selection criteria, preliminary items were prepared based on in-depth interviews with an experienced wedding planner group and a comprehensive review of previous studies, such as studies on selection criteria in the wedding industry and service work similar to wedding planners and wedding planner selection criteria. The preliminary items were tested for content validity using a focus group interview, comprising people in the wedding industry, and were refined accordingly. Then, the definitive quantitative questionnaire items were developed after conducting a preliminary survey. The main survey for this study was conducted using the responses of 295 consumers taking an Internet questionnaire. Exploratory factor analysis, Cronbach's alpha, and confirmatory factor analysis were adopted to develop the scale, which was tested for convergent validity and discriminant validity. This study is academically significant in that it developed a selection criteria scale tailored to wedding planners to address an area that has not been covered in previous studies. It is recommended that future studies conduct empirical analyses using the selection criteria developed in this study to compare influential variables that could affect behavior intention.

A Study on the Analysis for Aerodynamic design of centrifugal Compressor of the Marine Turbocharger (박용 터보챠저 원심압축기의 공력설계에 대한 해석적 연구)

  • Oh, Kook-Taek;Kim, Hong-Won;Ghal, Sang-Hak;Ha, Ji-Soo;Ryu, Seung-Chan
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.649-654
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    • 2001
  • This paper describes aerodynamic preliminary design performance prediction and flow analysis for centrifugal compressor of the marine middle engine turbocharger. The performance characteristics of turbocharger compressor are investigated at various operating conditions using mass flow rate and revolution speed, and computational flow analysis for impeller and diffuser at design point are performed. Preliminary design results correspond to actual compressor geometric values comparatively by applying modified slip factor. Performance prediction and flow analysis results show good agreement with experiments. Therefore, this will provide the performance prediction in preliminary design, and help to increase the design capability for optimized impeller.

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Aerodynamic Design of the Axial Fan (축류 송퐁기의 공력학적 설계)

  • Sohn, Sang-Bum;Joo, Won-Gu;Cho, Kang-Rae;Nam, Hyung-Baik;Yoon, In-Kyu;Nam, Leem-Woo
    • 유체기계공업학회:학술대회논문집
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    • 1998.12a
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    • pp.64-69
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    • 1998
  • In this study, a preliminary design method of the axial fan was systematically established based on the two-dimensional cascade theory. Flow deviation, lift coefficient, distribution of velocity and pressure coefficient on blade surfaces were predicted by an inviscid theory of Martensen method, which was also applied to select an airfoil of required performance in the present design process. The aerodynamic performance of designed blades can be predicted quickly and reasonably by using the through-flow calculation method in the preliminary design process. It would be recommendable to adopt three-dimensional viscous flow calculation at the final design refinement stage.

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Preliminary Experimental Results of Pressure Control for Modulatable Thruster Applications (노즐목 가변 추력기의 압력제어 기법에 관한 예비실험 결과)

  • Choi, Jae-Sung;Huh, Hwan-Il
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.18-21
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    • 2011
  • In this study, basic research on the pressure control using driven pintle of modulatable thruster is presented. For this purpose, pintle thruster and pintle shape was developed. The actuator model was selected by calculating pintle load using Fluent software. Preliminary unsteady experimental results show that huge pressure oscillation is occurred as the pintle approach toward nozzle wall. From the preliminary experimental results, we could see possibility of pressure control of the modulatable thruster.

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Preliminary Design Program Development for Gas Turbine Combustor (가스터빈 연소기 기본 설계 프로그램 개발)

  • Kim, Daesik;Kim, Jinah;Jin, You In
    • Journal of the Korean Society of Combustion
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    • v.20 no.3
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    • pp.27-34
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    • 2015
  • The objective of the current study is to introduce detailed process for a preliminary combustor design, and to develop a computer code for it. The program includes various empirical and semi-empirical methodologies for diffuser deign, combustor sizing, air distribution, and sub-component design such as primary and secondary zones. Using the developed program, the combustor sizing results are shown from an assumption of simple annual combustor cycle analysis. Two options are employed, 1) pressure loss approach, and 2) velocity assumption approach. Design results show that there are no significant differences in combustor sizing between two design options. Further code improvement is required for performance and emission evaluations of the designed combustor.

A PRELIMINARY STUDY ON QUANTITATIVE ANALYSIS USING THE COMPUTERIZED T-SCAN SYSTEM (COMPUTERIZED T-SCAN SYSTEM을 이용한 정량적 교합분석방법에 관한 연구)

  • Yang, Jae-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.27 no.2
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    • pp.271-277
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    • 1989
  • The purpose of this preliminary report was to describe the operating procedure of T-scan system and to identify the location, timing and force of occlusal contact in patient with normal occlusion using computerized T-scan system. From the preliminary observation , the author obtained the following results. 1. T-scan system displayed 2 dimensional and 3 dimensional description of occlusion: contact locations, timing (sequence) and forces of occlusal contacts. 2. The T-scan sensor was the most important part of the T-scan system. 3. The data of T-scan system cannot be stored in computer diskett. 4. The T-scan system is thought to be the most effective system to detect occlusal contacts and can be applied to the followings : occlusal diagnosis, occlusal equilibration, crown and bridge restorative procedures, denture adjustment, implant procedures, splint adjustment, laboratory procedures, periodontal treatment, orthodontics, TMJ treatment and patient education etc.

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A Study on the modeling of horizontal launch at submarine in the preliminary design phase (초기설계 단계에서의 잠수함 수평발사 모델링 연구)

  • Kim Dong-Hun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.7 no.3 s.18
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    • pp.38-46
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    • 2004
  • This paper deals with the development of simulation model for the horizontal launch at submarines in the preliminary design phase. The simulation model is composed of submarine motion model, cross flow force model in the bow of submarine, and weapon motion model In launch through torpedo tubes. Using submarine and weapon characteristics and simulation condition, it can simulate the exit velocity of weapon through torpedo tubes and reaction forces. It should be helpful for the analysis of the safe launch and design requirements in the preliminary design phase of a submarine or a weapon launched through torpedo tubes.

A Study on the UNCITRAL's Preliminary Draft Instrument on the Carriage of Goods by Sea (UNCITRAL의 해상화물운송협약의 예비초안에 관한 연구)

  • Choi, Myung-Kook
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.20
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    • pp.267-292
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    • 2003
  • UNCITRAL considered a proposal to include in its work program a review of current practices and laws in the area of the international carriage of goods by sea, with a view to establishing the need for uniform rules where no such rules existed and with a view to achieving greater uniformity of laws. And UNCITRAL Working Party, as of April, 2003, is reviewing the UNCITRAL's Preliminary Draft Instrument which was originally prepared by CMI. As said above, the Preliminary Draft Instrument has a lot of improved provisions in relation to the scope of application, period of responsibility, obligations and liability of carrier, obligations of shipper and so on, but it has also some provisions which should be reconsidered in light of changed environments. Therefore, UNCITRAL Working Party has to prepare more complete and widely adoptable new uniform rules under the sufficient discussion.

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