차동형 트랙션드라이브의 동력전달효율에 관한 연구

鄭然斗,韓世範,李正閏 三陟大學校 1999 論文集 Vol.32 No.1

This paper presents a study on the effect of the operating conditions on the traction characteristics of differential type traction drive. The cross roller type traction drive was used to observe the speed ratio and the power transmission efficiency of traction drive. The effects of spin motion and the power transmission efficiency between two tapered rollers of the traction drive are discussed and experimented. It is shown that the power transmission efficiency can increase up to 53% in the case of an experimental traction drive. the traction surface roughness of the tapered roller was also measured and observed by scanning electron microscope. On the basis of these results, the effects of specific sliding, roller speed, load, and contact pressure were clarified to a considerable extent.

Hydrogen Peroxide 농도와 적용시간이 Hydroxyapatite discs의 미백과 물리적 성질에 미치는 영향

양연미,이두철,백병주,김재곤,신정근 대한소아치과학회 2007 大韓小兒齒科學會誌 Vol.34 No.1

법랑질의 주성분인 hydroxyapatite 분말을 성형하고 소결하여 착색을 유발한 다음 과산화수소의 농도와 적용 기간의 변화에 따라 나타나는 미세 조직과 기계적 성질의 변화 및 미백 효과 등에 관한 연구를 통해 다음과 같은 결론을 얻었다. 1. 과산화수소의 농도와 적용시간이 증가함에 따라 미백 효과가 증가되었다. 2. 표면조도는 15% 과산화수소 10일, 30% 과산화수소 7, 10일 적용 시 유의한 차이로 증가하였다(p<0.05). 3. X-선회절 분석결과 미백처리 전·후의 결정상의 변화는 관찰되지 않았으나, 주사전자현미경 관찰시 표면의 미세구조는 과산화수소 농도와 적용시간의 증가에 따라 미세기공이 증가하였다. 4. 2축 굽힘강도는 30%농도의 과산화수소로 7, 10일 적용하였을 때 유의한 차이로 감소되었다(p<0.05). 5. 미소 경도값은 15% 과산화수소 10일과 30% 과산화수소 3, 7, 10일 적용 후 유의한 차이로 감소되었다(p<0.05) The purpose of this study was to evaluate the effect that various concentration and application time of hydrogen peroxide had on tooth whitening and physical properties. The hydroxyapatite (HA) discs of 12 mm (Φ) x 1.2 mm (t) in dimensions were made by compression (100 kg/㎠) and sintering (at 1350℃ for 2 hours). All specimens were polished sequentially with #240 through #2000 emery paper and one side of each specimen was polished finally with 0.3 ㎛ alumina paste. The discs were placed in sterile whole stimulated saliva overnight at 37℃ in order to form an in vitro pellicle layer. Then the discs were rinsed with distilled water and soaked into staining broth at 37℃ for 7 days. These stained specimens were bleached with hydrogen peroxide according to the change of concentration (3∼30%) and application time (3∼10 days). The specimens were analyzed with a spectrophotometer, X-ray diffractometer (XRD), scanning electron microscope (SEM), surface roughness tester, microhardness tester and biaxial flexural strength. The results of present study can be summarized as follows: 1. The bleaching effect was increased with the increased concentration and the extended application time of hydrogen peroxide. 2. The surface roughness was significantly increased from the specimen bleached with 15% hydrogen peroxide for 10 days and with 30% for 7 and 10 days respectively (p<0.05). 3. The changes of crystal phase observed by XRD between before and after bleaching weren' t shown of any difference, but microporous structure of surface observed by SEM was shown of increase with the increased concentration and the extended application. 4. The biaxial flexural strength was significantly decreased from bleaching of specimen with 30% hydrogen peroxide for 7 and 10 days respectively (p<0.05). 5. Microhardness was significantly decreased from bleaching with 15% hydrogen peroxide for 10 days and with 30% for 3, 7 and 10 days respectively (p<0.05). Although the tooth bleaching effect was greater when the high concentration was applied, further in vivo experiment will be needed to prove it s safety.

엘니뇨 현상에 의한 중서부태평양 한국 다랑어 선망어업 어장 변동

안두해,문대연,고정락,조규대,김동선 한국수산자원학회 2003 한국수산자원학회지 Vol.6 No.-

This paper describes the relationship between the distribution of fishing ground and E1 Nino events in the pacific Ocean which have occurred on a regular basis of 3-5 year terms. Anneal catches and catch ratios of skipjack. Katsuwonus pelamis and yellowfin tuna. Thunnus albacares largely increased during El Nino years due to the increasing of accessibility in accordance with the eastward extend of fishing ground, but vice versa during La Nina years. It is suggested that during El Nino years, the fishing grounds of Korean tuna purse seine fishery were extended to eastward in associated with the eastward advection of warm pool which was located in western equatorial Pacific Ocean during the normal state and characterized by the over 28℃ and low nutrients water masses.

산업로봇의 기구학적 성능 비교연구

김영탁,정연두,여인철 중앙대학교 생산공학연구소 1996 생산공학연구소 논문집 Vol.5 No.2

본 논문에서는 최적설계와 산업로봇의 응용에 있어 매우 중요한 여러가지 기구학적 성능을 다양한 산업로봇으로 평가하였다. 로봇 기구에 의존하는 조작성, 동력소비율 그리고 서어보 강성에 대하여 소개하고 분석하였다. 이러한 분석에 의해서 다음과 같은 사실을 얻을 수 있다. 첫째, 다관절형 로봇은 조작성이 우수하다. 둘째, 직교좌표형 로봇은 서어보 강성과 동력소비율이 우수하다. 마지막으로 극좌표형 로봇은 모든면에서 성능이 불리하다. 그것들은 로봇을 설계하는데 사용할 수 있다. Several mechanism performances, which are very important in the optimal design and application of industrial robots, are evaluated about various industrial robots in this paper. Manipulability, power dissipation ratio, and servo stiffness depending on mechanism of a robot are introduced and analysed. In the analysis, we could find the following facts. First, the articulated type robot has an advantage in manupulability. Second, the cartesian type robot has advantages in servo stiffness and power dissipation ratio. Finally, the polar coordinate type robot has disadvantages in all aspects. They could be used for designing a robot.

원자력 발전소내 부품의 이상 진동 진단 및 저감연구

김명수,임무승,정연두,김효준 三陟大學校 産業科學技術硏究所 2004 産業科學技術硏究論文集 Vol.9 No.1

In this paper, We researched the method analysing more easily the vibration source of motor to decrease trial and error in the vibration analysis when it is made high vibration in a big size motor driving vertical pump. According to this result, We made an easy calcalation expression to analysis the vibration source and decrease the vibration by eccentric ratio and clearance of bearing, deviation from roundness, slope of shaft, and slope of base plate, alignment variation by means of analysing the character of vibration happening to the degree. of inner clearance of motor.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

RNA-Seq Analysis is an Efficient Tool for Species Discrimination Markers Screening for Immunological Diagnosis of Pest Species

Doo-Sang Park,Chan-Seok Yeon,Chuleui Jung,Ki-Jeong Hong,Hyun Woo-Oh 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.04

Rapid identification of pest species found under quarantine is an important factor in preventing an economic loss of agricultural commodities. In this study, we analyzed RNA-Seq of the larvae of C. sasakii, G. molesta and G. dimorpha, which are serious pests in several fruits in Korea and are difficult to discriminate by species in their larval stage because of lack of a morphological character. To select immunological diagnostic markers, discriminating the larvae of C. sasakii from the G. molesta and G. dimorpha, RNA-Seq was performed for the larvae of the three insects. The 454 pyrosequencing generated 3,058-4,686 contigs for each three pest species, which assembled into 2,584-3,970 isotigs with average lengths of 829-1,244 bp. Functional annotation of the sequencing results generated 774 orthologs for the three pest species, and 12 isotigs were finally registered as candidate markers for species discrimination through bioinformatical screening, literature search, and gene expression study. The selected candidates include serine proteases, serpins, 27 kDa glycoprotein and storage protein with a constitutive gene expression in their larvae, pupae and adult stage.

영유아교사 이직의도 검사의 개발 및 타당화

정연두(Yeon Doo Jeong),조현철(Hyun Chul Cho) 대한사고개발학회 2023 사고개발 Vol.19 No.2

삼천포화력발전소 주변해역 퇴적물의 지구화학적 연구

이두호(Doo Ho Lee),임주환(Ju Hwan Lim),정연태(Yeon Tae Jeong),정년호(Nyeon Ho Jeong),강정원(Jeong Won Kang) 한국환경영향평가학회 2001 환경영향평가 Vol.10 No.2

This study was conducted to investigate the geochemical factors governing the distribution of heavy metals(Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the marine surface sediment samples collected from the Samcheonpo coal-fired power plant. Variations of absolute metal concentrations were related to those in textural and/or carbonate and organic matter content. Most elements, except for Pb, showed generally lower contents compared with the average shale concentration, and the effect of anthropogenic input appeared to be minimal in the sediments. Computations of LF%(labile fraction) and EF(enrichment factor) based on all trace metal data indicated the presence of mineralogical control for Co, Cr, Cu, Ni, and Zn, and anthropogenic contamination for Pb, which needs to be considered in the design of long term monitoring programmes.

Comparison of Growth Characteristics and Inorganic Components Between Korean and Japanese Codonopsis lanceolata

Soo Jeong Kwon,Tae Yeon Park,Moon Soon Lee,Hee Ock Boo,Gag Yeon Cho,Sun Hee Woo,Jin Woong Cho,Hee Doo Lee,Seong-Woo Cho,Hag Hyun Kim 한국작물학회 2015 Korean journal of crop science Vol.60 No.2

This study was performed to investigate the growth characteristics and inorganic components of Codonopsis lanceolata regarding regional differences. The plant height of Japanese Codonopsis lanceolata was 373.6 cm, so it’s revealed that it has more vigorous growth than Korean won. The flowering time of Korean Codonopsis lanceolata was 2 weeks faster than Japanese one. Total fresh weight of root was 41.0 g and 39.0 g for Korean and Japanese respectively, thus, no significance difference was found. However, regarding fresh weight, Korean one had a more fresh weight (35.4 g) of main root parts, but Japanese one had a more fresh weight (9.6 g) of the lateral root part. Each inorganic component was found more in the aboveground parts, regardless of the region and the content of K was the largest. Regarding the content of macroelements for each part of Codonopsis lanceolata, the content of Na, Mg, P, S, and Ca in Korean Codonopsis lanceolata was found the highest on the leaf, followed by stem and root. In the case of Japanese Codonopsis lanceolata, same result was found on the content of Mg and Ca, however, the highest content of Na and P was found in the stem.