입간측영(⽴竿測影)을 통해 만들어지는 각도기 기원에 관한 연구 - 선생님, 각도기는 어떻게 만들어졌나요? -

임정규,복기대 한국초등과학교육학회 2021 한국초등과학교육학회 학술대회 Vol.80 No.-

본 연구는 학생들이 “선생님 각도기는 어떻게 만들어졌나요? 왜 직각이 100°가 아니고 90°입니까?”라고 질문을 받았을 때 각도기 기원에 관한 자신 없는 답변에서 시작되었다. 현재 학계에서는 각도기의 기원에 관해서는 365일 지구의 공전에서 360° 각도기가 나왔다는 설과 바빌로니아의 60진법에서 유래되었다는 설 등이 있다. 본 연구자는 ‘각도기 180°는 자연계에서 만들어졌고, 태양의 일주운동 및 공전과 관계가 깊을 것으로 생각한다’. 본 연구에서는 고대인들이 “그림자 관측 즉, 입간측영을 통해 달력 및 해시계를 만드는 과정 속에서 각도기가 만들어졌다.”라는 가설을 실험을 통해 세우게 되었고, 직접 검증해 보았다. 각도기의 기원을 알아보기 위해 관측 실험과 천문 자료 수집을 통해 알아보았다. 넓은 대지에 기둥을 세우고 주변에 동지 남중 기준으로 원을 그리면 자연계에서 입간측영을 통해 각도기를 만들 수 있음을 알게 되었다. 또한, 미국 해양대기국 데이터 수집 분석을 통해, 각도기는 북반구 동절기(추분∼동지∼춘분) 180일 동안 아침, 저녁으로 태양의 일주운동 결과를 동지 기준으로 반원에 나타낸 것이 각도기라는 결과를 얻어낼 수 있었다. 북반구 동절기 자연계에서 만들어지는 각도기는 현재 쓰고 있는 각도기와 매우 흡사한 형태를 갖고 있다. 매일 매일 아침, 저녁으로 그림자의 위치가 하루에 약 1°(0.98∼1.02)씩 움직이므로 180칸으로 나누어짐을 다양한 통계를 통해 확인할 수 있었다. 관측 위치는 적도 인근에서 관측한 것으로 설계하였으나, 적도식으로 각도기를 적도면과 평행하게 세워 설계하면 지구 어디에서나 같은 값을 얻을 수 있음을 알 수 있었다. 본 연구를 통해 현재 사용 중인 180° 각도기와 유사한 각도기를 자연계에서 만들 수 있음을 입증해 내는 성과가 있었다고 생각한다. 현재의 360° 각도기는 입간측영 180° 각도기를 오랜 세월 동안 보완하여 오늘날의 360°에 이르렀을 것이라는 결론에 도달하게 되었다. 앞으로 현대 물리학과 천문학 전공자와 연계하여 각도기가 만들어진 과정을 보다 깊이 있게 토론하고 연구할 필요가 있다고 생각한다.

도로포장에서 표면조직깊이 측정에 대한 통계적 게이지 R&R 분석

임정규,김성준,최돈화,이승우 한국도로학회 2010 한국도로학회 학술발표회 논문집 Vol.2010 No.3

부산지역의 대기중 중금속 오염도에 관한 조사 연구

임정규 인제대학교 1987 仁濟醫學 Vol.8 No.1

부산지역의 3개 지역(서면, 사상, 대신동)의 주 간선도로변에 대하여 1985년 7월부터 10개월간 대기중 중금속(현, 카드뮴, 크롬 및 바나듐)의 농도를 AAS로 정량한 결과 연중 총 평균 농도는 연; 2.40±1.32μg/m3, 카드뮴 ; 0.30±0.11μg/m3, 크롬 ; 1.52±0.52μg/m3 및 바나듐; 1.54±0.55μg/m3이었으며 지역별 평균 농도는 각 중금속 공히 사상>서면>대신동의 순이었다. For the purpose of assessing the degree of heavy metal pollution in the atmosphere in order to contribute to the health improvement of the residents in Pusan, the author measured the Pb, Cd, Cr and V levels in the ambient air at the locations by season and time (morning, afternoon and night) from July, 1985 to April, 1986 with the carbon furance atomic absorption spectrophotometer. The locations selected were Somyon, Sasang and Daeshin-dong, which have been known as commerical, industrial and residential areas respectively in Pusan. The results were as follows; 1.The average concentrations of heavy metals during a year were Pb; 2.60 ± 1.32μg/m3, Cd; 0.30 ± 0.11㎍/m3, Cr; 1.52 ± 0.52㎍/m3 and V; 1.54 ± 0.55 ㎍/m3. 2.The average concentrations of heavy metals by area were the highest at Sasang, and the lowest at Daeshin-dong. 3.The average concentations of heavy metals by season were relatively higher in the summer than in the remainder of the year. 4.The average concentrations of heavy metals during the day were relatively higher in the afternoon or at night than in the morning.

연 작업자들의 업종별 보건관리에 의한 건강수준의 변화

임정규,안규동,이병국 순천향대학교 산업의학연구소 1996 순천향산업의학 Vol.2 No.1

In order to evaluate the effect of industry type specific occupational health service on the health status of lead workers, total 39,203 record of 5 year accumulated data of workers from 1989 to 1993 in lead using industries which made special contract of group occupational health service with Soonchunhyang university, institute of industrial medicine were studied. Blood zinc protoporphyrin (ZPP) and 15 lead related symptoms were selected as a health indices and air concentration of lead (PbA) was selected as a environmental index of lead industries. Blood ZPP and symptoms survey were carried out twice a year for lead workers and once a year for non-lead office workers. Environmental measurements of lead in air were done twice a year in every lead using industries. Lead industries were divided into 4 group of lead industries arbitrarily such as storage battery industries for group I, secondary smelting, litharge making and related operation for group II, telecommunication for group III and primary smelting and crystal glass making for group IV. Data for group III only available for 3.5 years from 1990 to first half of 1993. Blood ZPP was measured with hematoflurometer (Aviv model 206). Fifteen questionnaire of lead related symptoms were provided to all workers and filled by themselves and confirmed by interview doctor at the site. The results obtained were as follows: 1. While the geometric means of lead in air of group I, II, IV in 1989 were 0.333, 0.353 and 0.113 ㎎/㎥, those in 1993 were decreased to 0.081, 0.162 and 0.037 ㎎/㎥ respectively. On the other hand the geometric means of lead in air of group III were always below 0.020 ㎎/㎥ throughout the study period. 2. While the geometric mean of lead in air in medium/large storage battery industries was 0.313 ㎎/㎥ in 1989, it was decreased to below 0.05 ㎎/㎥ since 1992, that in small storage battery industries was 0.395 ㎎/㎥ and it was still 0.101 ㎎/㎥ in 1993. This data suggested that the effect of group occupational health service were more effective in medium/large storage battery industries. 3. The overall percent of distribution of lead in air of below 0.05, 0.05-0.15 and over 0.15 ㎎/㎥ in group I for 5 years were 87.54%, 9.29% and 3.16% respectively. On the other hand, for group II and III, those were 77.19%, 15.21%, 7.6% and 92.78%, 3.72%, 3.5% respectively. The overall percent of distribution of lead in air of above three category in medium/large and small storage battery industries were 90.42%, 7.32%,2.25% and 79.96% 14.47%, 5.57% respectively. 4. The mean blood ZPP of male lead workers decreased from 52.61±68.67 ㎍/100ml in 1989 to 33.31±34.62 ㎍/100ml and those of female lead workers decreased from 84.01±79.06 ㎍/100ml in 1989 to 58.35±47.30 ㎍/100ml. While the mean blood ZPP of male lead workers for group I, II and IV in 1989 was 39.65±40.41, 132.9±121.1 and 32.9±55.51 ㎍/100ml, those in 1993 were 29.75±28.38, 77.35±64.48 and 31.41±21.35 respectively. The mean blood ZPP for group III were ranged from 13.11±8.53 to 26.43±8.83 ㎍/100ml for 3 and half years period. 5. The mean blood ZPP of male lead workers in medium/large and small storage battery industries in 1989 were 32.16, 82.53 ㎍/100ml in 1989 and those in 1993 were decreased to 25.69 and 76.22 ㎍/100ml respectively. Those of female lead workers in both industries in 1989 were 53.36, 126.3 ㎍/100ml and 43.68, 90.17 ㎍/100ml respectively. 6. The overall percent of distribution of blood ZPP of below 50, 50-99, 100-149 and over 150 for 5 years were 72.83% (male: 76.63%, female: 44.59%), 16.97% (male:15.23, femlae: 29.93%), 5.23% (male: 4.18%, female: 13.04%) and 4.96% (male: 3.96%, female: 12.44%) respectively. Among 4 groups, the percent of workers whose blood ZPP over 50 ㎍/100ml was highest in group II. 7. The mean of overall symptoms of male and female lead workers in 1989 were 5.2 and 4.9 and decreased to 4.6 and 4.3 in 1993 respectively. The mean of overall symptoms of male and female lead workers in medium/large storage battery industries in 1989 were 5.7, 5.9 and decreased to 4.8, 5.2 in 1993. Those in small storage battery industries in 1989 werer 4.8, 5.2 and 3.8, 3.2 respectively. 8. The most frequent symptom among 15 lead related symptom questionnaires for 5 year duration was 'generally fatigue' (male: 63%, female: 53%) and the least frequent symptom was 'acute abdominal pain around umbilicus' (male: 12%, femlae: 9%). Among male lead workers of 4 groups the prevalence of lead related symptoms was highest in group 4 and followed by group 3, 1 and 2 in descending order. Among female lead workers it was highest in group 3 and followed by group 1, 2, and 4 in descending order. 9. The prevalence of lead related symptoms were high in group whose blood ZPP below 100㎍/100ml than those with blood ZPP over 100 ㎍/100ml. The prevalence of lead related symptoms of male lead exposed workers were higher or same with male non-lead exposed workers in every symptoms except questionnaire 11. But for female workers the prevalence of lead related symptoms of lead exposed workers were lower than non-exposed lead workers except questionnaire 1, 4, 5, 6, 7, 8, 12, 15. 10. There was very similar pattern of symptom prevalence over the 5 years in lead exposed and non-exposed workers for both sex. 11. The prevalence of lead related symptoms was higher in young age group than old age group and there was no big difference of prevalence according to the work duration. With above results, group occupational health service for lead workers improved working condition of lead industries under special contract with Soonchunhyang university, institute of industrial medicine in term of decrease of lead in air, particularly more effective in medium/large storage battery industries. It also brought out the the decrease of lead burden of most lead workers in terms of blood ZPP of lead workers which is a good index of lead intoxication. But symptom servery did not give any clue of dose-response relationship between lead exposure and lead related symptoms with current symptom questionnaire. It is recommended to revise the way of questioning lead related symptoms from lead workers. On the other hand, for group II and III, those were 77.19%, 15.21%, 7.6% and 92.78%, 3.72%, 3.5% respectively. The overall percent of distribution of lead in air of above three category in medium/large and small storage battery industries were 90.42%, 7.32%,2.25% and 79.96%, 14.47%, 5.57% respectively.

주조용(鑄造用) 합금(合金)의 조직반응(組織反應)에 관(關)한 실험적(實驗的) 연구(硏究)

임정규,Lim, Jeong-Kyu 대한치과보철학회 1976 대한치과보철학회지 Vol.14 No.1

The author studied the effects of some dental gold alloys and dental nonprecious metals on muscle. The metal specimens were cast in the size of $1.0mm.{\times}5.0mm.{\times}3.0mm.$ and implanted in the gluteus maximus musculus of the two dogs. The subjects were sacrificed at 3 weeks and 5 weeks respectively after implantation. The tissue was examined his to-pathologically. The findings were as follows. 1. The more the alloy contains gold, the less the tissue response to the alloy and the less the connective tissue layer around the specimens. 2. The recovery of connective tissue layer in gold specimens was markedly observed. 3. There were very thick connective layers around nonprecious specimens.

치관보철물(齒冠補綴物)의 인접변연부위(隣接邊緣部位)에 작용(作用)하는 Stress에 관(關)한 광탄성학적(光彈性學的) 분석(分析)

임정규,Lim, Chung-Kyu 대한치과보철학회 1980 대한치과보철학회지 Vol.18 No.1

The purpose of this study was to investigate the stresses in different proximal margins and to measure, quantitatively, the effect of different modifications in the design of preparations on the stresses using two-dimensional photoelasticity. Photoelastic stress analysis is based on the phenomenon, exhibited by most transparent solids, of becoming birefringent, or doubly refracting, when strained. Two birefringent materials were used in this study, PSM-1 and PSM-5 in .standard sheet ($10'{\times}10'{\times}\frac{1}{4}'$ thickness), PSM-1(polyester) was used for constructing the substructure, and PSM-5(epoxy resin) was used in making the restorations to be investigated. Two birefringent materials were used in the construction of composite photoelastic model. Seven variable models were constructed. The peripheral dimensions of all model were constant and the models represent an occlusomesial section of a lower posterior molar. Model 1 represents the knife edge margin (shoulderless), Model 2 represents the chamfer, Model 3 represents a rounded shoulder(no sharp angle between the axial wall and gingival floor), Model 4 represents a flat shoulder (axial wall is a $90^{\circ}$ angle to the gingival wall), Model 5 represents $+15^{\circ}$ angulation, Model 6 has a $-15^{\circ}$ angulation, and Model 7 is the same as Model 4 except that it has a $45^{\circ}$ bevel. Improved artificial stone was used to represent dental cement in luting the composite photoelastic model. Static loading procedures(100 pounds) were used at preplanned sites. The results were as follows; 1. The stresses in the proximal portion of all tested models were compressive in nature when the proximal shoulders were loaded vertically on the same proximal marginal ridge. 2. The round and chamfered preparations were the optimum designs in proximoocclusal restorations. They showed the lowest stress concentration factor, i.e. 2.16 and 2.23, respectively. The knife edged shoulder had the highest value, K=5.39. Round type shoulder geometry experiments reduced the stress concentration factor (S.C.F.) 3. The gingival portion of proximal shoulder geometry was a critical location for stress concentration.

WBI 활용 과학 학습지도 자료 개발 및 적용

임정규 강원과학교육연구회 2002 세미나 Vol.2002 No.1

Effects of atorvastatin on the induction of experimental cerebral aneurysm in a high lipid diet rat model

임정규,여인성,이진석,이형진,양지호,이일우 대한뇌혈관외과학회 2010 Journal of Cerebrovascular and Endovascular Neuros Vol.12 No.3

Objective : Previously, we reported that a high lipid diet significantly increases the induction rate of cerebral aneurysm (CA) formation in an experimentally induced CA rat model, suggesting that hypercholesterolemia with chronic inflammation leads to aneurysm formation. To elucidate the role of hypercholesterolemia in CA formation, experimentally induced CA was evaluated in rats fed a high lipid diet and treated with low and high doses of atorvastatin. Methods : Thirty-seven, 7-week-old male Sprague-Dawley rats underwent a CA induction procedure. The control animals (n = 11) were fed a normal diet, and the experimental animals (n = 26) were fed a diet containing high lipid content for 3 months. The experimental group comprised a high-dose atorvastatin group (20 mg/kg/day, n = 15) and low-dose atorvastatin group (1 mg/kg/day, n = 11). Three months after the operation, induction of CA formation in the three groups was analyzed. Results : Induced CA formation was 67%, 63%, and 36% in the control, high lipid/high atovastatin, and high lipid/low atovastatin group, respectively. The differences resulting from high-dose and low-dose atorvastatin were significant (Pearson k2, P = 0.028 and 0.029, respectively). Conclusions : A high lipid diet can significantly increase induction of CA formation. However, the lack of decreased induction in atorvastatin-treated animals suggests that high and low doses of atorvastatin do not inhibit the potential effects of hypercholesterolemia on CA formation. Further studies, such as those utilizing apolipoprotein E knockout mice, are necessary to elucidate the exact role of hypercholesterolemia in the pathophysiology of CA. (Kor J Cerebrovascular Surgery 12(3):196-201, 2010)

Cefoperazone(T-1551)의 약리학적 연구

임정규,홍사악,박찬웅,김명석,서유헌,신상구,김용식,김혜원,이정수,장기철,이상국,장우현,김익상,Lim J.K.,Hong S.A.,Park C.W.,Kim M.S.,Suh Y.H.,Shin S.G.,Kim Y.S.,Kim H.W.,Lee J.S.,Chang K.C.,Lee S.K.,Chang K.C.,Kim I.S. 대한약리학회 1980 대한약리학잡지 Vol.16 No.2

The pharmacological and microbiological studies of Cefoperazone (T-1551, Toyama Chemical Co., Japan) were conducted in vitro and in vivo. The studies included stability and physicochemical characteristics, antimicrobial activity, animal and human pharmacokinetics, animal pharmacodynamics and safety evaluation of Cefoperazone sodium for injection. 1) Stability and physicochemical characteristics. Sodium salt of cefoperazone for injection had a general appearance of white crystalline powder which contained 0.5% water, and of which melting point was $187.2^{\circ}C$. The pH's of 10% and 25% aqueous solutions were 5.03 ana 5.16 at $25^{\circ}C$. The preparations of cefoperazone did not contain any pyrogenic substances and did not liberate histamine in cats. The drug was highly compatible with common infusion solutions including 5% Dextrose solution and no significant potency decrease was observed in 5 hours after mixing. Powdered cefoperazone sodium contained in hermetically sealed and ligt-shielded container was highly stable at $4^circ}C{\sim}37^{\circ}C$ for 12 weeks. When stored at $4^{\circ}C$ the potency was retained almost completely for up to one year. 2) Antimicrobial activity against clinical isolates. Among the 230 clinical isolates included, Salmonella typhi was the most susceptible to cefoperazone, with 100% inhibition at MIC of ${\leq}0.5{\mu}g/ml$. Cefoperazone was also highly active against Streptococcus pyogenes(group A), Kletsiella pneumoniae, Staphylococcus aureus and Shigella flexneri, with 100% inhibition at $16{\mu}g/ml$ or less. More than 80% of Escherichia coli, Enterobacter aerogenes and Salmonella paratyphi was inhibited at ${\leq}16{\mu}/ml$, while Enterobacter cloaceae, Serratia marcescens and Pseudomonas aerogenosa were somewhat less sensitive to cefoperagone, with inhibitions of 60%, 55% and 35% respectively at the same MIC. 3) Animal pharmacokinetics Serum concentration, organ distritution and excretion of cefoperazone in rats were observed after single intramuscular injections at doses of 20 mg/kg and 50 mg/kg. The extent of protein binding to human plasma protein was also measured in vitro br equilibrium dialysis method. The mean Peak serum concentrations of $7.4{\mu}g/ml$ and $16.4{\mu}/ml$ were obtained at 30 min. after administration of cefoperazone at doses of 20 mg/kg and 50 mg/kg respectively. The tissue concentrations of cefoperazone measured at 30 and 60 min. were highest in kidney. And the concentrations of the drug in kidney, liver and small intestine were much higher than in blood. Urinary and fecal excretion over 24 hours after injetcion ranged form 12.5% to 15.0% in urine and from 19.6% to 25.0% in feces, indicating that the gastrointestinal system is more important than renal system for the excretion of cefoperazone. The extent of binding to human plasma protein measured by equilibrium dialysis was $76.3%{\sim}76.9%$, which was somewhat lower than the others utilizing centrifugal ultrafiltration method. 4) Animal pharmacodynamics Central nervous system : Effects of cefoperazone on the spontaneous movement and general behavioral patterns of rats, the pentobarbital sleeping time in mice and the body temperature in rabbits were observed. Single intraperitoneal injections at doses of $500{\sim}2,000mg/kg$ in rats did not affect the spontaneous movement ana the general behavioral patterns of the animal. Doses of $125{\sim}500mg/kg$ of cefoperazone injected intraperitonealy in mice neither increased nor decreased the pentobarbital-induced sleeping time. In rabbits the normal body temperature was maintained following the single intravenous injections of $125{\sim}2,000mg/kg$ dose. Respiratory and circulatory system: Respiration rate, blood pressure, heart rate and ECG of anesthetized rabbits were monitored for 3 hours following single intravenous inje

자율운항선박 사이버안전체계 구축방안

임정규,최상훈,박개명 한국항해항만학회 2022 한국항해항만학회 학술대회논문집 Vol.2022 No.춘계