원격조작에 의한 작업대상물 강성과 마찰 특성의 동정

권혁조,전지명,김진옥,문일동,오재윤 전북대학교 공학연구원 ( 구 전북대학교 공업기술연구소 ) 2002 工學硏究 Vol.33 No.-

This study performs a workpiece stiffness and frictional characteristic identification experiments by teleoperation. Experiments are performed using a bilateral force feedback teleoperation system. It is composed of a master manipulator, the slave manipulator equipped with a force/torque sensor, and a real-time control system. To control the teleoperation system, a position-force controller is developed. The slave manipulator is controlled by the master manipulator's position command and the master manipulator is controlled by the force information from the slave manipulator. This study presents a method to find the slave manipulator's stiffness. And, this study presents a method to compute the workpiece stiffness based on the measured pressing force and deflection at the slave manipulator. Also, this study performs a workpiece frictional characteristic identification experiments. In the experiments, the slave manipulator rubs a workpiece with an arbitrary pressing force. While the slave manipulator rubs a workpiece, a vertical force and a frictional force are measured and the ratio of a frictional force to a vertical force is considered as a frictional characteristic.

유치열기 정상교합아동의 측모두부방사선 계측연구

김지연,권장혁,김경호,박기태 大韓小兒齒科學會 2005 大韓小兒齒科學會誌 Vol.32 No.4

본 연구의 목적은 유치열기 부정교합의 진단자료로 사용할 수 있는 정상 계측치를 알아보는 것이다. 4세에서 6세 사이 유치열기 정상교합아동 32명의 측모두부방사선 계측사진 및 안모사진을 이용하여 악골 및 연조직의 전후방적, 수직적 관계를 분석하였다. 수평적인 골격성 계측항목 중 SNA는 83°,SNB는 78.72°,ANB는 5.28°를 나타내어 하악골이 상악골에 비해 후방에 위치하고 있었으며 수직적인 골격성 계측항목 중 Gonial angle은 127°를 나타내어 성인에 비하여 High angle pattern을 보였다. 연조직 분석에서는 성인에 비해 convex한 soft tissue profile이 관찰되었다. 치성 계측항목 중 U1 to SN은 91.04°, IMPA는 86.57°를 나타내어 성인에 비해 reteroclination된 상하악 유중절치가 관찰되었다. 정상교합아동의 골격성분석에서 여자가 남자에 비하여 평균 나이가 많음에도 불구하고 linear measurement는 전제적으로 남자가 여자보다 큰 수치를 보였다. The present study was designed to formulate cephalometric norms of normal occlusion for usage in orthodontic diagnosis of malocclusion in Korean children. Thirty two children, aged 4 to 6. with normal occlusion were chosen for this study. Sagittal and vertical relations were analyzed using lateral cephapogram and clinical photos and the measurements were compared with those of adults. On skeletal sagittal analysis, the mean values of the SNA and SNB angles were 83°and 78.72°. It showed that the mandible was retrognathic and retropositioned in comparison to those angle pattern in children and reduction of gonial angle due to counterclockwise rotation of the mandible. On dental analysis. the mean values of the U1 to SN and IMPA were 91.04° and 86.57°, This showed retroclined upper and lower deciduous teeth in comparison to adults. For values. the linear values were generally greater in males than females.

실험동물에서의 내분비계 교란물질인 DEHP, DBP의 생체내 영향

정지윤,이성호,박영석,박병권,김병수,김상기,박창식,강경선,이영순 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

The major protocol features of the rodent uterotrophic assay have been evaluated using a range of reference chemicals. The protocol variables considered include the selection of the test species and route of chemical administration, the age of the test animals, the maintenance diet used, and the specificity of the assay for estrogens. The rodents were ovariectomized under general anesthesia via bilateral flank incisions and randomly assigned to groups of 5 animals. This study investigated the estrogenic effects of phthalates, which are DEHP and DBP, suspected as endocrine disruptors. It is concluded that three daily subcutaneous administration of test chemicals, which are di-ethylhexyl phthalate(DEHP) and di-n-butyl phthalate(DBP), to 9 week-old rodents. The results revealed that DEHP & DBP show similar uterotrophic activity in the rat and the mouse, using subcutaneous administration. DEHP and DBP failed to affect any of these parameters, which are body weight, mammary gland, vaginal and uterus histopathology. but, DBP increased uterus weight to only one rat of 1.0 g/kg group. The results conform the need for rigorous attention to experimental design and criteria for assessing estrogenic activity.

하수슬러지를 이용한 복합소재 개발연구

연규석,권윤환,유근우,김남길,김동준,이윤수 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-

본 연구는 하수 종말 처리에 의해 발생되는 하수 슬러지를 잔 골재(경량골재)로 사용하여, 폴리머 콘크리트를 제조하여 그 때의 역학적 성질에 대하여 검토하였다. 하수 슬러지는 5일간 110±5℃에서 수분함량 0.1%미만으로 건조한 후 파쇄하여 No.4∼No. 200 번체의 잔골재 표준 시방서 기준에 부합되도록 사용하였다. Pellet는 보통 회전pan에서 만드나, 본 실험에서는 수동으로 제조하였다. 제조한 하수 슬러지 경량 골재는 평균 겉보기 비중은 1.58(g/㎤), 단위용적중량은 1.98(t/㎥)으로 KS F 2534의 경량골재의 절건비중과 단위용적에 따른 분류에 의하면 중위급(medium weight) 경량골재에 속하는 것으로 측정되었다. 또한 잔 골재 중 하수 슬러지 경량 골재를 0%, 5%, 10%, 15%, 20%, 25%, 30%로 치환하여 그때의 압축, 휨, 인장강도를 측정하였다. 그 결과 하수 슬러지의 증가에 따라 강도 감소를 보였으나, 일반 경량콘크리트 제조 또는 단열용 콘크리트 블록 제조에 사용이 가능하다고 사료된다. 그러므로 앞으로 건조수축, 크리이프 특성 및 내구성에 관한 연구가 더욱 심도 있게 이루어져야 폐자원인 하수 슬러지를 이용한 건자재의 개발이 가능하리라 판단된다. In this study, the polymer concrete was produced by using the lightweight aggregate that had been manufactured using the sewage sludge and its physical properties were experimentally examined. Experimental results show that when the portion of sewage sludge lightweight aggregate in the fine aggregate increases, slump values decreases. Also, the compressive, the flexural and the tensile strengths decrease when the portion of sewage sludge lightweight aggregate increases. Although its strengths decreases, the sewage sludge lightweight fine aggregates is thought to be used for construction materials.

구내 표준 방사선사진을 이용한 구내방사선촬영기의 선질 평가

이상섭,권혁락,심우현,오승현,이지연,전국진,김기덕,박창서 대한구강악안면방사선학회 2000 Imaging Science in Dentistry Vol.30 No.3

Purpose : This study was to evaluate the beam quality of intraoral X-ray equipments used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. Materials and Methods : The study was done using the intraoral X-ray equipments used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Results : Most of the HVLs of intraoral X-ray equipments were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-705 model of prosthodontic dentistry department, and the REX601 model at the student clinic were relatively low. Conclusion : HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion. (Korean J Oral Maxillofac Radiol 2000; 30: 183-188)

반려동물의 기생충검사 이론 및 실제

이성호,박영석,박병권,김상기,정지윤,박수진,박창식,김병수 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

The aim of this article is to improve human health and that of companion animals by improving the diagnosis and control of parasitic diseases. This is achieved by research into parasites of veterinary significance including zoonoses and the use of comparative systems to increase our understanding of some human parasitic diseases. We should promotes learning and teaching through knowledge and operates a diagnostic unit that offers a service to pet owner for indigenous and exotic parasitic diseases of companion animals. We must diagnose and treat them early. Zoonotic parasites are very important because many of animal parasites are zoonoses and give pain and death to human. Parasites are divided Protozoa, Helminthes and Arthropods. There are many protozoa, about 65,000 species. Arthropods are the vector of another diseases, such as virus, bacteria, protozoa and nematodes. Helminthes are composed of Trematoda, Cestoda, Nematoda and Acanthocephala. The target of Veterinary Parasitology is to recognize the characteristics of these parasites and subsequently diagnose, treat and control them. This article is intended to familiarize you with the essential facts and concepts of companion animal parasitology. Emphasis is placed on fecal sample techniques (comparison of fecal examination techniques; frequently found artifacts in fecal smears; direct Smear; zinc sulfate flotation; etc.) We recommend that the study be done to more references on animal parasites.

미약한 경부기종에 의해 발생된 개의 부분적 기관협착

이성호,박영석,박병권,김병수,정지윤,박창식,김상기 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

A 10-year old male Pomerarian was presented with about a ten day history of stridor and severe paroxysmal honkinglike coughing which were aggravated with excitement and exercise. Auscultation revealed prominent inspiratory and expiratory crackles and wheezes over the caudal cervical trachea which were heard equally over both side of the chest, and a hemogram showed mild leucocytosis with mild dehydration. On the lateral radiographs of the neck and thorax, the cervical trachea was displaced ventrally by the air trapped between fascial planes of the cervical area near the thoracic inlet. It also revealed a marked narrowing of the tracheal lumen extending from the level of the fifth cervical to the second thoracic vertebra, and the lung field was judged to be within normal limits. There was no evidence of pneumomediastinum. A diagnosis of segmental tracheal stenosis was made. The emphysema of the retrotracheal area was thought to be a traumatic origin. The dog was treated successfully with strict cage confinement for a week. The tracheal stenosis caused by mild emphysema between the soft tissue of the cirvical area or mediastinum in the dog is very rare.

Characteristics of methicillin resistant <i>Staphylococcus aureus</i> isolated from chicken meat and hospitalized dogs in Korea and their epidemiological relatedness

Kwon, Nam Hoon,Park, Kun Taek,Jung, Woo Kyung,Youn, Hwa Young,Lee, Yeonhee,Kim, So Hyun,Bae, Wonki,Lim, Ji Youn,Kim, Ji Yeon,Kim, Jun Man,Hong, Soon Keun,Park, Yong Ho Elsevier 2006 Veterinary microbiology Vol.117 No.2

<P><B>Abstract</B></P><P>Methicillin resistant <I>Staphylococcus aureus</I> (MRSA) is one of the most important pathogens in human and veterinary hospitals. The isolation of MRSA from animals and foodstuffs has been reported with an increased incidence. However, methicillin (oxacillin) is not used in animal husbandry or in animal hospitals in Korea. In this study, three pre-MRSA and one silent <I>mecA</I>-carrying methicillin susceptible <I>S. aureus</I> (smMSSA) were isolated from retail chicken meat, and three MRSA were isolated from hospitalized dogs in Korea. The three pre-MRSA isolates were determined to have a staphylococcal cassette chromosome <I>mec</I> (SCC<I>mec</I>) type III, and the smMSSA isolate was not classified. The animal hospital isolates were found to contain SCC<I>mec</I> type II. Seven and 15 <I>S. aureus</I> isolated from hospitalized humans and bovine milk, respectively, were also examined in this study in order to determine the epidemiological origins of MRSA. Multilocus sequencing typing (MLST) revealed that the chicken meat and bovine milk isolates were closely related to the animal hospital isolates. The SCC<I>mec</I> characteristics and MLST analyses indicated the possibility of the human to animal transmission of MRSA. These results highlight the importance of identifying MRSA carriers as well as intercepting MRSA transmission because MRSA is becoming increasingly widespread without any plausible relationship with the use of methicillin (oxacillin).</P>

Effect of Medicinal Herb Extracts on Antioxidant and Anti-stress Activities in Rat

Ji-Youn Yoo,Ji-Min Lim,Hyuk-Jin Kwon,Ji-Ho Choi,Yoon-Hee Choi,Shin-Young Park 한국식품영양과학회 2012 한국식품영양과학회 학술대회발표집 Vol.2012 No.10

Association between circadian preference and blood lipid levels using a 1:1:1 propensity score matching analysis

Kwon, Yu-Jin,Chung, Tae-Ha,Lee, Hye Sun,Park, JuYoung,Chung, Ji-Youn,Lee, Byoung-Kwon,Lee, Ji-Won Elsevier 2019 Journal of clinical lipidology Vol.13 No.4

<P><B>Background</B></P> <P>Previous studies indicate that circadian preference is associated with various energy metabolism and metabolic disorders. However, little is known about the associations between a circadian rhythm and blood lipid levels, especially in humans.</P> <P><B>Objective</B></P> <P>The aim of the study was to investigate whether the circadian rhythm affects serum lipid levels in Korean adults.</P> <P><B>Methods</B></P> <P>We designed a cross-sectional study to evaluate the associations between circadian preference and blood lipid levels in Korean adults. A total of 1984 participants (range of age 19–81 years) were included in this study. Propensity scores were calculated using logistic regression with age, sex, and body mass index. A total of 435 subjects were evaluated by propensity score matching analysis, equally distributed into morningness, intermediate, and eveningness groups, each with 145 subjects. Circadian preference was evaluated by the Morningness-Eveningness Questionnaire.</P> <P><B>Results</B></P> <P>Participants with the evening preference had significantly higher levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, and non–high-density lipoprotein cholesterol (non–HDL-C) when compared with those with morning or intermediate preference, after adjusting for confounding variables. Regarding other lipid parameters, both total cholesterol/HDL-C and low-density lipoprotein cholesterol/HDL-C in the evening preference are significantly higher than those of other circadian preferences. Evening preference was also significantly associated with a higher atherogenic index of plasma.</P> <P><B>Conclusion</B></P> <P>Our study demonstrates that there is a significant association between circadian preference and blood lipid levels. Our findings suggest that individuals with evening preference could have a greater risk of atherosclerotic cardiovascular diseases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Circadian rhythms regulate a variety of physiological functions in humans. </LI> <LI> This cross-sectional study was conducted using 1:1:1 propensity score matching. </LI> <LI> Evening preference potentially has a more atherogenic lipid profile. </LI> <LI> The circadian rhythm plays a key role in lipid metabolism. </LI> </UL> </P>