DDA를 이용한 하드웨어 보간기의 계산효율 향상에 관한 연구

오준호,최기봉 대한기계학회 1988 대한기계학회논문집 Vol.12 No.5

본 연구에서는 직선보간과 원호보간에서 계산효율을 향상시킬 수 있는 방법을 제시하여 이 방법과 가감속 구간을 고려한 하드웨어 보간기를 설계 및 제작하였고, 이 것을 스텝 모터에 의해 구동되는 밀링머시인에 연결하여 보간기의 성능을 알아보았다. The maximum feedrate generated from the hardware DDA is closely related to its calculation efficiency. The smaller interpolation span results in the lower calculation efficiency. This paper presents the method to improve the calculation efficiency for the smaller interpolation span. For the linear interpolation the higher calculation efficiency can be achieved by putting biggest value that the interpolation DDA can hold. for the circular interpolation, however, the scheme used for linear interpolation does not work since arbitrary change of value in the interpolation DDA changes the radius of the circle. The bit length of the hardware DDA is adjusted instead of adjusting the value in DDA, which results in the every same effect on calculation efficiency for the circular interpolation. The hardware circuit and supporting software are designed, and tested by two axis step motor driven milling machine. The experimental results show that the proposed method drastically increases the maximum feedrate even for the smaller interpolation span.

단일계수적응을 통한 강건한 적응제어시의 설계및 안정성 해석

오준호 대한기계학회 1990 대한기계학회논문집 Vol.14 No.2

In adaptive control, the lack of persistent and rich excitation causes the estimated parameters to drift, which degrade the performance of the system and may introduces instability to the system in a stochastic environment. To solve the problem of the parameter drift, the concept of single parameter adaptation is presented. For the parameter identification, a priori error is directly used for adaptation error. The structure of the controller is based upon the minimum variance control technique. The stability and robustness analysis is carried out by the sector stability theorem for the second order system. The computer simulation is performed to justify the theoretical analysis for the various cases.

자동제어 교육에서의 컴퓨터 소프트웨어 이용

오준호 대한기계학회 1988 大韓機械學會誌 Vol.28 No.2

컴퓨터는 그 자체만으로도 일반인의 흥미와 관심을 불러일으키기에 충분한 기자재이다. 이러한 컴퓨터를 자동제어 교육에 십분 활용함으로써 교육효과를 극대화시킬 수 있을 것이다. 이를 위하여 교육에 대한 과감한 투자로서 컴퓨터등 기자재를 과감히 확보하고 이를 활용함과 아울러 이에 따른 적절한 교과내용의 재검토가 이루어져야 할 것이다. 본 글에서는 주로 컴퓨터 시뮬 레이션 등 소프트웨어 활용에 대하여 주로 언급하였으나 이를 데이터수집 및 해석, 디지틀 제어 등 하드웨어로서의 컴퓨터 활용도 더욱 교육에 도입되어야 할 것이다.

한의학 고문헌 텍스트에서의 저자 판별- 기능어의 역할을 중심으로 -

오준호 대한한의학원전학회 2020 대한한의학원전학회지 Vol.33 No.2

Objectives : We would like to study what is the most appropriate "feature" to effectively perform authorship attribution of the text of Traditional East Asian MedicineMethods : The authorship attribution performance of the Support Vector Machine (SVM) was compared by cross validation, depending on whether the function words or content words, single word or collocations, and IDF weights were applied or not, using ‘Variorum of the Nanjing’ as an experimental Corpus. Results : When using the combination of 'function words/uni-bigram/TF', the performance was best with accuracy of 0.732, and the combination of 'content words/unigram/TFIDF' showed the lowest accuracy of 0.351. Conclusions : This shows the following facts from the authorship attribution of the text of East Asian traditional medicine. First, function words play an important role in comparison to content words. Second, collocations was relatively important in content words, but single words have more important meanings in function words. Third, unlike general text analysis, IDF weighting resulted in worse performance. 목적 : 한의학 고문헌 텍스트에서 저자 판별(authorship attribution)을 효과적으로 수행하기 위해 가장 적합한 ‘특성(feature)’이 무엇인지 검토해 보고자 한다. 방법 : 『난경집주(難經集註)』를 실험 코퍼스(Corpus)로 하여, 기능어(function words)와 내용어(content words), 단어(single word)와 연어(collocation), IDF 가중치 적용 여부에 따라 서포트 벡터 머신(SVM;Support Vector Machine)의 저자 판별 성능을 교차검증(cross validation) 방식으로 비교하였다. 결과 : ‘기능어/유니-바이그램/TF’를 사용한 경우, 정확도 0.732로 가장 좋은 성능을 보였고, ‘내용어/유니그램/TFIDF’ 조합이 0.351로 가장 낮은 정확도를 보였다. 결론 : 이를 통해 한의학 고문헌 저자 판별에서 다음과 같은 사실을 알 수 있었다. 첫째, 기능어가 내용어에 비해 중요한 역할을 한다. 둘째, 내용어에서는 상대적으로 연어가 중요했지만, 기능어에서는 단어가 더 중요한 의미를 가진다. 셋째, 일반적인 텍스트 분석에서와 달리 IDF 가중치 적용이 더 좋지 않은 결과를 가져왔다.

Resonance Frequency Analysis(RFA)를 이용한 임플란트 종류간의 초기 안정성 비교

오준호,장문택,Oh, Jun-Ho,Chang, Moon-Taek 대한치주과학회 2008 Journal of Periodontal & Implant Science Vol.38 No.3

Purpose: The objective of this study was to compare initial implant stability measured by RFA between different implant systems during the initial healing period. Material and Methods: Fifty-four patients (36 males/18 females) who had been treated at the Department of Periodontology, Chonbuk National University Dental Hospital during the period between January and November in 2007 were included in the study. The mean age of the subjects was 49 years old (18 to 77). A total of 104 implants (Type A: 3i $Osseotite^{(R)}$, Type B: $Replace^{(R)}$ select, Type C: ITI implant) were placed following the manufacturer's standard surgical protocols. Implant stability quotient (ISQ) readings were obtained for each implant at the time of surgery, 2-, and 4-month postoperatively. Result: No implant was failed during the observation period. At the baseline, the difference between mean ISQ values of 3 implant systems was statistically significant (p<0.05). However, at 2-, and 4-month following implant surgery, no significant difference was observed between ISQ values of the implant systems. In the same implant, the ISQ values of Type B and C implants increased (p<0.05), but those of Type A implants decreased during the 2-month healing period. The mean ISQ values of Type B and C implants showed a increasing tendency, while those of Type A implants were stable for the 4-month follow-up period. Conclusion: Within limits of this study, it can be concluded that implant design and surface topography of implant might influence the ISQ value and changing pattern during the initial healing period.

북한 고려의학 학술 저널에 대한 저자 및 키워드 네트워크 분석

오준호,이은희,이주연,김동수,Oh, Junho,Yi, Eunhee,Lee, Juyeon,Kim, Dongsu 대한예방한의학회 2021 대한예방한의학회지 Vol.25 No.2

Objectives : This study seeks to grasp the current status of Koryo medical research in North Korea, by focusing on researchers and research topics. Methods : A network analysis of co-authors and keyword which were extracted from Koryo Medicine - a North Korean traditional medicine journal, was conducted. Results : The results of author network analysis was a sparse network due to the low correlation between authors. The domain-wide network density of co-authors was 0.001, with a diameter of 14, average distance between nodes 4.029, and average binding coefficient 0.029. The results of the keyword network analysis showed the keyword "traditional medicine" had the strongest correlation weight of 228. Other keywords with high correlation weight was common acupuncture (84) and intradermal acupuncture(80). Conclusions : Although the co-authors of the Koryo Medicine did not have a high correlation with each other, they were able to identify key researchers considered important for each major sub-network. In addition, the keywords of the Koryo Medicine journals had a very high linkage to herbal medicines.

PC와의 인터페이스

오준호 대한기계학회 1990 大韓機械學會誌 Vol.30 No.1

인터페이서(interfacer)라함은 성격이 다른 두가지 이상의 장치를 연결시켜 정보의 교환을 가능하 게 하는 공유영역을 의미한다. 본 글에서는 이해하기 쉬우며 응용 범위도 넓은 I/O포트 방식의 인터페이스를 중심으로 작동원리, 회로설계에, 제작 및 실험에 관하여 간략하게 살펴보기로 하 겠다. 본 글중 PC라함은 IBM PC/XT 및 호환 기종을 일컬으며, 여기에 언급되는 기술은 XT급뿐 아니라 AT급의 PC에도 무리없이 적용될 수 있다.

2차원 광학 위치 센서에 관한 연구 ( A Study on the Rotation Free Optical Position Sensor in Two Dimensional Tracking )

오준호,제우성 대한전자공학회 1988 대한전자공학회 학술대회 Vol.1988 No.01

16세기 조선 의서 "이석간경험방"에 나타난 전통지식 분석 : 죽과 밥을 이용한 식치 처방을 중심으로

오준호,Oh, Junho 대한예방한의학회 2013 대한예방한의학회지 Vol.17 No.1

Objectives : Medical treating with eating foods is one of important therapies in East Asian traditional medical knowledge and is referred as a therapy to treat diseases through foods. Since the food cannot be separated from ordinary people living, the medical treating with eating foods is a therapy with strong locality and contains many autogenous parts. Methods : Recently, the world is showing much interest for genetic resources, and the concept of intellectual property is rapidly expanding as the field of 'new knowledge property right' as well. Thus, the knowledge of medical treating with eating foods recently draws much attention in the economic aspect beyond the scholarly interest for traditional medicine. Here, I would like to summarize and report the contents related to medical treating with eating foods on "Yi, SeikKan experience prescriptions" which was discovered before. Results & Conclusions : First, medical treating with eating porridge on "Yi, SeikKan experience prescriptions" is classified into one with nonglutinous rice as the main ingredient and the other with other grains as the main ingredient. It is differently utilized depending on the nature of the grain. Second, medical treating with eating rice on "Yi, SeikKan experience prescriptions" was born from our nation's unique way of living and is classified into one way to eat rice mixed with ground medicinal herbs, another one to cook and eat rice with mixed grains and the other way to use as the external application. Medical treating with eating rice is assumed to replace the meal. Third, "food section" was given separately and discussed in this book. There were some parts different from existing medical knowledge due to the accumulation of experience using medicinal herbs. Fourth, we should pay attention to experience a book on medicine where vibrant medical information has been recorded in order to discover and process our traditional knowledge resources as a useful form.

밀링머신의 절삭력 제어를 통한 표면굴곡도 향상에 관한 연구

오준호,정충영 대한기계학회 1988 대한기계학회논문집 Vol.12 No.2

본 논문에서는 엔드 밀링에서 황삭 작업시 비교적 절삭 모델의 정립이 용이한 하향 밀링(down milling)의 경우를 대상으로, 가공면 오차의 주 원인인 공구와 공작물 사이의 처짐과 절삭력의 특정한 동적관계를 유도하고, 그 절삭력을 일정하게 유지하도록 공구의 이송속도를 온라인으로 제어하였다. To improve the surface waviness in the peripheral milling, the feedrate is controlled so that the cutting force measured in the normal direction to the workpiece is constant. A discrete time first order model between the feedrate and the tool deflection is derived for the control. It has been shown by the analysis that the tool deflection is directly related to the feedrate and largely affects the surface waviness during cutting. The experimental results shown that the surface waviness is drastically improved by the proposed methods.