• 한국정밀공학회지
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• 제19권6호
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• pp.70-76
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• 2002

Effectiveness of corrective machining algorithm is verified experimentally in this paper by performing corrective machina work practically to single side and double sides hydrostatic tables. Lapping is applied as machining method. Machining information is calculated from measured motion errors by applying the algorithm, without information on rail profile. It is possible to acquire 0.13$\mu$m of linear motion error, 1.40arcsec of angular motion error in the case of single side table, and 0.07$\mu$m of linear motion error, 1.42arcsec of angular motion error in the case of double sides table. The experiment is performed by an unskilled person after he experienced a little of preliminary machining training. Experimental results show that corrective machining algorithm is very effective, and anyone can improve the accuracy of hydrostatic table by using the algorithm.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.413-418
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• 2005

Vibration test using the MAST(Multi Axial Simulation Table) is more reliable test than conventional testing process focused on one directional vibration test. The former test could be possible with a advanced control algorithm and hardware supports so that most of the operation is automatically conducted by MAST system itself except the input information that is derived from the measured data. That means the reliability of the vibration test is highly depended on the input profile than any other cases before. In this paper, the optimal algorithm based on energy method is introduced so that the best combination of candidated input PSD data could be constructed. The optimal algorithm renders time information so that the vibration fatigue test is completely possible for any measured signals one wants. The real road test is conducted in short intervals containing some rough roads and the candidated input PSD is obtained from the extra road in proving ground. The testing is targeted for the electronically operated door and seat.

• 한국소음진동공학회논문집
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• 제18권3호
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• pp.368-374
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• 2008

Multi-axial simulation table(MAST) is widely used in motor companies as the multi-axial excitor for vibration fatigue of target component, which provides the vibrational condition as close as the vehicle test. However, the vibration fatigue performance of target component can be guaranteed with MAST system only in case the input profile covers the required severity of the target component on field test. In this paper, the signal processing for multi-axial vibration fatigue test on vehicle component is presented, from the data acquisition of the target component to the derivation of input profile. To compare the severity of vibration condition between field and proving ground, the energy principle of a equivalent damage is proposed and then, it is determined the optimal combination of special events on proving ground using a sequential searching optimal algorithm. To explain the vibration methodology clearly, seat and door component of vehicle are selected as a example.

• 한국생산제조학회지
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• 제19권5호
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• pp.678-683
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• 2010

The drum cam with rotational follower is used to apply the ATC and index table of machine tools and it has the merit of minimizing the backlash. In general, to machine the drum cam with rotational follower, 5-axis CNC machine must be used and its kinematic principle must be included in modeling on CAM. So, the commercialized CAM software can't be applied to this machining of drum cam. Though some special software for machining drum cam was developed, it could be applied to special 5-axis CNC machine tools and the finish machining module was not applied. To solve this problem, this study includes the induction of the post processing algorithm for the rough machining of drum cam on several 5-axis CNC machine tools, type AC, AB and Be. The finish machining software will be treated in next study. A sample drum cam was machined on 5-axis CNC machine tool of AC type. The designed geometric profile of drum cam consist to the measured profile after machining well. This post processing algorithm for rough machining of the drum cam was clearly verified.

• 한국소음진동공학회논문집
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• 제15권9호
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• pp.1070-1076
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• 2005

Vibration test using the MAST(multi axial simulation table) provide a more reliable testing environment than any conventional one. The multi axial simulation could be possible with a advanced control algorithm and hardware supports so that most of the operation is automatically conducted by MAST system itself except the input information that is synthesized by the measured response signals. That means the reliability of the vibration test is highly depended on the quality of the input profile. In this paper, the optimal algorithm based on the energy method is introduced to construct a best combination of candidated input PSD data could be constructed. Since the optimal algorithm renders time information, the nitration fatigue test is completely possible for any measured signals one wants. The proposed method is explained with representing acquired road signals from the candidate input PSD obtained from a proving ground.

• 농업생명과학연구
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• 제46권6호
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• pp.43-49
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• 2012

본 연구는 수간곡선식을 이용하여 아까시나무의 입목 수간재적표를 개발하고자 수행하였다. 이용한 수간곡선식은 Kozak 모형이었으며, 모형의 모수를 추정하였다. 추정한 모형은 통계적으로 적합성이 인정되었으며, 잔차분석 결과도 양호한 것으로 판정되었다. 따라서 본 모형이 아까시나무 수간재적표를 조제함에 있어 충분히 이용될 수 있을 것으로 사료된다. 그리고 수간재적표는 이용자의 편의를 위하여 수피 포함 및 수피제외 재적표를 조제하고자, 수피두께추정식을 개발하여 이용하였다. 수피두께추정식 역시 통계적으로 유의성이 인정되었다. 따라서, 본 모형이 아까시나무 수간재적표를 조제함에 있어 충분히 이용될 수 있을 것으로 사료된다. 또한, 국내에서 처음으로 개발한 아까시나무의 수간재적표는 임학뿐 만 아니라 타 분야에 널리 사용되기를 기대한다.

• 경영과학
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• 제17권3호
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• pp.119-129
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• 2000

Design of web site must include community considerations alongside technical design aspects. The main purposes of this study are to identify the community criteria for evaluating web site and to examine how business web sites include the community factors. To identify the evaluation criteria, the author reviewed recent literatures and made a table showing a summary result(see Table 1). appendix shows a sample form NASDAQ(n=82) and KOSDAQ(n=59) which were evaluated. Using the evaluation from with 189 items(Table 3), all sites were visited and review between August 28, 2000 and September 6, 2000. The auther’s evaluations were done from the perspective of community building in business sector. Table 4, summary data on the results of the study, shows that the level of application of the community concept is very low. Among the listed 18 items, only a few items are utilized at more than 50% level. Less than 10% items are Member Profile, Group Segmentation, Backstory, Forum, Chat, Fact-to-face Meeting, and Collaborative Design. the unbalanced utilization due to the lack of community concept in businesses are found. Korea firms are superior to NASDAQ firms in terms of Bulletin Board and FAQ; But Korean firms are inferior and remain at very low level in terms of Member Login, Education Materials, Backstory, Forum, and Integrating Off-line Activities which are core factors of community building.

• 대한기계학회논문집A
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• 제34권8호
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• pp.1029-1034
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• 2010

본 논문은 회전체의 진원도 및 흔들림 정밀도 측정에 관한 연구이다. 일반적으로 가공물 진원도 측정은 정밀한 회전테이블 또는 기준 원형 디스크를 필요로 하여, 고가의 비용이 소요된다. 축차2점법은 2개의 변위센서를 사용하여 직선가이드 등에서진직도 측정을 위하여 사용되었으며, 본 연구에서는 이 방법을 회전체에 적용하였다. 한 개의 디스크를 이용하여 측정된 회전체 변위 측정값에서 장치의 회전시 흔들림 오차를 제거하여 회전체의 순수한 진원도 프로파일을 측정하였다. 본 연구는 정밀한 기준 디스크 (Artifact)를 사용하지 않고 원형 가공물의 진원도 프로파일 측정에 유용할 것이다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.71-74
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• 2001

Using the Taguchi method, optimum process condition of lead frame blanking has been determined in the point of view of shape of blanked profile. As the main process parameters, clearance, strip holding pressure and bridge width are selected. According to the orthogonal array table, three levels of experiment have been carried out for each factors. The optimal blanking condition is analyzed with the SN ratio. It has been verified that the optimal process condition can be determined with a combination of basic blanking experiment and experiment design method. Both the effect of each factors and gain can be judged in the quantitative manners from the analysis of SN ratio.

• 소성∙가공
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• 제11권2호
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• pp.132-137
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• 2002

Using the Taguchi method, optimum process condition of lead frame blanking has been determined in the point of view of shape of blanked profile. As the main process parameters, clearance, strip holding pressure and bridge width are selected. According to the orthogonal array table, three levels of experiment have been carried out for each factor. The optimal blanking condition is analyzed with the SN ratio. It has been verified that the optimal Process condition can be determined with a combination of basic blanking experiment and experiment design method. Both the effect of each factor and gain can be judged in the quantitative manner from the analysis of SN ratio.