Reperfusion Arrhythmia에 관한 연구 1. 관상동맥 폐색위치에 따른 Reperfusion Arrhythnia 발생

최인혁,Choi In-Hyuk 한국임상수의학회 1989 한국임상수의학회지 Vol.6 No.2

The incidence of reperfusion arrhythmia(RA) according to occlusive position of coronary artery was induced in 25 open-chest dogs anestherized with halothan, these were ligated between anterior ventricular branch and marginal branch of left circumflex artery for 30 minutes and after releasing of the ligation, the incidence of RA was observed during 5 minutes. The incidence rate of RA occurred in 36%(9 heads) of the cases, 20%(5 heads) of them died before reperfusion and 44%(11 heads) of them survived after reperfusion. In the classification according to the length of anterior ventricular branch in left circumflex artery, the incidence rate of RA occurred in 80% of the group I(5 heads) which belongs to short size of anterior ventricilar branch, in 50% of the group II (8 heads) which belongs to medium size, in 8.3% of the group III(12 heads) which belongs to long size and in 61.5% of the groups I and II(13 heads). These results showed the higher incidence rate of RA than in other occlusive position (left anterior descending artery), and it may be estimated that the incidence of RA changed with the significant difference according to the lengthe of anterior ventricular branch, in other words, dimension of ischemic area in left ventricle.

정상적(正常的)인 한우(韓牛)의 심전도(心電圖)에 관(關)한 연구(硏究) I. 표준지유도(標準肢誘導)

최인혁,정인성,김남수,서두석,Choi, In-hyuk,Jung, In-sung,Kim, Nam-soo,Suh, Doo-seok 대한수의학회 1993 大韓獸醫學會誌 Vol.33 No.4

The electrocardiographic(ECG) parameters on the standard limb leads in the normal Korean native cattle have been measured with a 3 channel Electrocardiograph built in a computed analysis. The study was conducted on the animals 98 heads of mean age of 17.7 months. Conduction parameters, waves, intervals and segments have been recorded. The recordings were analyzed as to shape and amplitude of the P and T waves and the components of the QRS complex. Heart rate was recorded by the Electrocardiogram which were a mean of $80.4{\pm}11.6beats/min$. And the younger had a higher heart rate than the older one. Average conduction times in the RP, the QRS complex and the QTc interval recorded $166.7{\pm}23.1msec.$, $79.7{\pm}8.8msec.$ and $395.5{\pm}30.4msec.$, in the P and T wave duration recorded $70.1{\pm}13.5msec.$ and $97.6{\pm}16.9msec.$, and in the PR and ST segment duration recorded $97.9{\pm}23.5msec.$ and $173.9{\pm}40.3msec.$, respectively. The wave forms in each lead observed various types. The amplitudes of wave type showed the highest frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of the positive type showed the frequency of 65.3%, 82.7% and 52.0% in leads I, II and III that were $103.1{\pm}47.8{\mu}V$, $115.2{\pm}37.3{\mu}V$ and $67.4{\pm}26.9{\mu}V$, and it showed the frequency of 54.1% and 85.7% in the leads aVL and aVF that were $63.7{\pm}23.0{\mu}V$, $88.0{\pm}83.6{\mu}V$, respectively. Average amplitude of the negative type showed the frequency of 78.6% in lead aVR which was $99.3{\pm}38.0{\mu}V$. 2. Average amplitude of the QRS complex were from $362.8{\pm}177.7{\mu}V$ to $532.8{\pm}253.9{\mu}V$(mean of $449.1{\pm}57.2{\mu}V$) that in all leads except lead I were manifested the Low-Voltage QRS complex(below 0.5mV). Average amplitudes of each wave type in the QRS complex aere $-50.2.4{\pm}258.2{\mu}V$ and $-428.6{\pm}195.1{\mu}V$ in the QS groups type that showed a frequency of 66.3%, 70.4% in the leads I and aVL, were $451.1{\pm}20.4.0{\mu}V$, $387.6{\pm}175.8{\mu}V$ and $299.3{\pm}146.5{\mu}V$ in the R groups type that showed a frequency of 48.0%, 53.1% and 34.7% in the leads III, aVR and aVF, and were $-307.5{\pm}180.3{\mu}V$, $201.4{\pm}77.2{\mu}V$ in the QR wave type which showed a frequency of 39.8% in lead II, respectively. 3. In T wave, amplitude of the positive type showed the frequency of 50.0%, 82.7%, 51.0% and 57.1% in leads II, III aVR and aVF which were $214.9{\pm}115.6{\mu}V$, $188.5{\pm}119.3{\mu}V$, $191.0{\pm}93.7{\mu}V$ and $165.7{\pm}91.9{\mu}V$, and the negative type showed a frequecny of 66.3% and 72.5% in leads I and aVL. that were $221.3{\pm}112.5{\mu}V$, $-173.6{\pm}86.7{\mu}V$, respectively. 4. Amplitude of ST segment in leads I, II and III were a mean of $-12.2{\pm}37.2{\mu}V$, $17.5{\pm}42.6{\mu}V$ and $28.3{\pm}40.4{\mu}V$, in leads aVR, aVL and aVF were $-3.9{\pm}32.5{\mu}V$, $-15.9{\pm}35.6{\mu}V$ and $26.2{\pm}37.5{\mu}V$, respectively.

정상적(正常的)인 한우(韓牛)의 심전도(心電圖)에 관(關)한 연구(硏究) II. 흉부단극유도(胸部單極誘導)의 파형(波形)과 전위(電位)

최인혁,김수용,김남수,서두석,Choi, In-hyuk,Kim, Soo-young,Kim, Nam-soo,Suh, Doo-seok 대한수의학회 1993 大韓獸醫學會誌 Vol.33 No.4

Electrocardiographic parameters of amplitude and the shape of waves on the unipolar precordial chest leads in the normal Korean native cattles have been measured with a 3 channel electrocardiograph built in a computed and analysis. The study was conducted on 98 heads of mean age of 17.6 months. The wave forms of P, T and QRS complex wave in all leads showed various types. The parameters of the amplitude in the wave types showed the most frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of positive type showed a frequency of 92.9% and 93.9% in leads $CV_6LU$ and $CV_6LL$ that were $83.8{\pm}31.0{\mu}V$ and $76.0{\pm}30.7{\mu}V$, and negative type showed a frequency of 97.9% in lead V 10 that were $-80.2{\pm}29.4{\mu}V$, respectively. But the plate type in leads $CV_6RU$ and $CV_6RL$ showed frequency of 48% and 58.3%, respectively. 2. Average amplitude of the QRS complex were in a range of $277.0{\pm}154.0{\mu}V$ to $648.2{\pm}146.2{\mu}V$(mean of $418.8{\pm}139.4{\mu}V$) in all leads that were manifested the Low-Voltage QRS complex(below 1 mV in unipolar precordial leads). Average amplitudes of each wave type in the QRS complex were $-250.0{\pm}139.8{\mu}V$ and $-399.2{\pm}226.8{\mu}V$ in the QS group types that showed a frequency of 50.0% and 82.5% in the leads $CV_6LU$ and $CV_6LL$, respectively. And average amplitudes of the R group types showed a frequency of 85.6%, 56.1% and 75.8% in the $CV_6RU$, $CV_6RL$ and $V_{10}$ that were $321.5{\pm}142.1{\mu}V$, $271.6{\pm}139.9{\mu}V$ and $552.4{\pm}132.7{\mu}V$, respectively. 3. In T waves, Amplitudes of the positive type showed a frequency of 60.2%, 46.9% and 83.7% in leads of $CV_6LL$, $CV_6RU$ and $CV_6RL$ that were respectively $184.7{\pm}93.7{\mu}V$ $103.7{\pm}64.43{\mu}V$ and $111.8{\pm}39.3{\mu}V$, the negative type showed a frequency of 62.2% and 93.7% in leads $CV_6LU$ and $V_{10}$ that were $142.2{\pm}82.1{\mu}V$ and $-280.3{\pm}107.2{\mu}V$, respectively. 4. Average amplitude of ST segment were $3.7{\pm}33.1{\mu}V$, $0.9{\pm}23.1{\mu}V$, $10.9{\pm}28.6{\mu}V$, $5.8{\pm}28.3{\mu}V$ and $-34.7{\pm}48.4{\mu}V$ in leads $CV_6LL$, $CV_6RU$, $CV_6RL$, $CV_6LU$ and $V_{10}$ respectively.

AE기법을 이용한 자기애자의 손상 분석

최인혁,신구용,임윤석,구자빈,손주암,임대연,오태근,윤영근,Choi, In-Hyuk,Shin, Koo-Yong,Lim, Yun-seog,Koo, Ja-Bin,Son, Ju-Am,Lim, Dae-Yeon,Oh, Tae-Keun,Yoon, Young-Geun 한국전기전자재료학회 2020 전기전자재료학회논문지 Vol.33 No.3

This paper investigates the soundness of porcelain insulators associated with the acoustic emission (AE) technique. The AE technique is a popular non-destructive method that measures and analyzes the burst energy that occurs mainly when a crack occurs in a high-frequency region. Typical AE methods require continuous monitoring with frequent sensor calibration. However, in this study, the AE technique excites a porcelain insulator using only an impact hammer, and it applies a high-pass filter to the signal frequency range measured only in the AE sensor by comparing the AE and the acceleration sensors. Next, the extracted time-domain signal is analyzed for the damage assessment. In normal signals, the duration is about 2ms, the area of the envelope is about 1,000, and the number of counts is about 20. In the damage signal, the duration exceeds 5ms, the area of the envelope is about 2,000, and the number of counts exceeds 40. In addition, various characteristics in the time and frequency domain for normal and damage cases are analyzed using the short-time Fourier transform (STFT). Based on the results of the STFT analysis, the maximum energy of a normal specimen is less than 0.02, while in the case of the damage specimen, it exceeds 0.02. The extracted high-frequency components can present dynamic behavior of crack regions and eigenmodes of the isolated insulator parts, but the presence, size, and distribution of cracks can be predicted indirectly. In this regard, the characteristics of the surface crack region were derived in this study.

개의 비유합(非癒合) 골절(骨折) model에 있어서 동결건조골이식(凍結乾燥骨移植)의 효과(效果)

최인혁,김현경,김남수,사사키 노부오,Choi, In-hyuk,Kim, Hyeon-gyeong,Kim, Nam-soo,Sasaki, Nobuo 대한수의학회 1996 大韓獸醫學會誌 Vol.36 No.2

To investigate the effectiveness of the freeze-dried allografts and fibrin glue in bone grafts, the status of new bone formation and union of the grafted bone were observed in three types of grafting bones; autogenic bone(AT), allogenic bone(AL), and allogenic bone particles mixed with fibrin glue(FG). These were transplanted into non-union fracture model of 7 adult dogs with 2cm defect made in the proximal metaphysis of both fibulae. The autogenic and allogenic grafting bones had been treated by a modified freeze-dried method. The serial radiogram were observed the repair process of grafted bones biweekly until 17 or 21 weeks after transplantation and the observation of histological aspects, tetracycline double labeling and microradiography in the grafted bones were undertaken at 17 or 21 weeks after transplantation. The incorporation of bone minerals to the non-union fracture models were accomplished in 4 of 5 cases grafted with AL and in 2 of 4 cases grafted with AT. None of 5 cases grafted with FG were incorporated. The process of new bone formation and resorption in the grafted bones were observed three types; resorption of the grafted bones after newbone formation(type A) in 4 cases, new bone formation after resorption(type B) in 2 cases and complete or incomplete resorption without new bone formation(type C) in 8 cases. The modified freeze-dried method used in this study contributed to inhibite the rejection in allogenic grafts but the union period of the grafted freeze-dried bone was more prolonged than that of fresh autografts. Fibrin glue did not contribute to induce a new bone formation ofbone grafts.

송전용 애자의 산불영향에 따른 특성 연구

최인혁,최장현,이동일,정용운,유근양,Choi, In-Hyuk,Choi, Jang-Hyun,Lee, Dong-Il,Chung, Yong-Woon,Yu, Kun-Yang 한국조명전기설비학회 2005 조명·전기설비학회논문지 Vol.19 No.2

본 논문에서는 산불이 송전용 폴리머애자에 미치는 영향을 연구하기 위해 인공화염 시험장치를 제작하여 화염의 가열 시간에 따른 폴리머애자의 갓(shed) 변화와 자기애자의 disc 변화를 관찰하고, 전기적$\cdot$기계적 실험을 통하여 특성변화를 확인하였다. 실험결과 다음과 같은 결론을 얻을 수 있었다. 첫째, 화염의 가열시간이 5분정도 경과하였을 때, 자기애자의 전기적 특성은 $80(\%)$ 정도 저하된 반면에 폴리머애자의 경우 갓 유실이 있었지만 전기적 특성의 변화는 $10(\%)$ 정도였다. 폴리머애자를 20분 가열하였을 때는 대부분의 갓이 유실되었지만 전기적 특성치는 $20(\%)$ 정도 감소하였다. 둘째, 폴리머애자와 자기애자 모두 전기적 특성치의 감소는 있었지만 기계적 특성치는 양호하게 나타났다. In order to understand the effect of the mountain fire on the polymeric insulator for transmission lines, the author observed the deformation of the sheds of the polymeric insulators and the change of the discs of the porcelain insulators under fire, and investigated the electrical and mechanical characteristics of the insulators after the ignition test As the result the following conclusions were obtained. First, the porcelain insulator was degraded in electrical characteristics when the insulator was subjected to the fire for approximately 5 minutes; whereas, the polymeric insulator was not degraded though there were some damage on its sheds. Second, after 20 minutes exposure to the fire, the polymeric insulator lost a lot of parts of sheds, but the electrical characteristics was lowered by around $20(\%)$, but the porcelain insulators were electrically degraded by more than $80(\%)$.

Recovery of the Vanadium and Tungsten from Spent SCR Catalyst Leach Solutions by Hydrometallurgical Methods

최인혁,문경혜,전종혁,이진영,라제쉬 쿠마 죠티,Choi, In-Hyeok,Moon, Gyeonghye,Jeon, Jong-Hyuk,Lee, Jin-Young,Jyothi, Rajesh Kumar The Korean Institute of Resources Recycling 2020 資源 리싸이클링 Vol.29 No.2

In new millennium, wide-reaching demands for selective catalytic reduction (SCR) catalyst have been increased gradually in new millennium. SCR catalyst can prevent the NO_x emission to protect the environment. In SCR catalyst the main composition of the catalyst is typically TiO₂ (70~80%), WO₃ (7~10%), V₂O₅ (~1%) and others. When the SCR catalysts are used up and disposed to landfills, it is problematic that those should exist in the landfill site permanently due to their extremely low degradability. A new advanced technology needs to be developed primarily to protect environment and then recover the valuable metals. Hydrometallurgical techniques such as leaching and liquid-liquid extraction was designed and developed for the spent SCR catalyst processing. In a first stage, V and W selectively leached from spent SCR catalyst, then both the metals were processed by liquid-liquid extraction process. Various commercial extractants such as D2EHPA, PC 88A, TBP, Cyanex 272, Aliquat 336 were tested for selective extraction of title metals. Scrubbing and stripping studies were tested and optimized for vanadium and tungsten extraction and possible separation. 3^rd phase studies were optimized by using iso-decanol reagent.

송전용 36,000 lbs 자기애자의 수명 예측 연구

최인혁,최연규,이동일,이원교,강병규,박준호,Choi, In-Hyuk,Choi, Yon-Gyu,Lee, Dong-Il,Lee, Won-Kyo,Kang, Byoung-Kyu,Park, Jun-Ho 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.7

36,000lbs porcelain insulators of D-1995, D-1997 and D-2002 investigated mechanical and electrical qualities, where is process of using in the Korea 154 kV transmission lines. It analyzes the cause of the elapse of a year aging of the transmission insulators. Weibull distribution function, product quality and uniform quality, etc. investigated for prediction to extant life of insulator. It calculate change as statistical elapse of a year through product qualities of used insulator and new insulator, uniform equality and uniformity of insulator. In case of D-1995 year used insulator, it decided to badness decline index k by 0.0237, badness quality index by 1.0 and 3.0. Result of extant confidence life Ym was calculated that remain each 4 yens and 0.7 yens that uniformity index is considered. Extant life of D-1997 and D-2002 insulators Predicted by about 40 years.

베이지안 방법론을 적용한 154 kV 송전용 자기애자의 수명 평가 개발

최인혁,김태균,윤용범,이준신,김성욱,Choi, In-Hyuk,Kim, Tae-Kyun,Yoon, Yong-Beum,Yi, Junsin,Kim, Seong Wook 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.9

It is extremely important to improve methodologies for the lifetime assessment of porcelain insulators. While there has been a considerable amount of work regarding the phenomena of lifetime distributions, most of the studies assume that aging distributions follow the Weibull distribution. However, the true underlying distribution is unknown, giving rise to unrealistic inferences, such as parameter estimations. In this article, we review several distributions that are commonly used in reliability and survival analysis, such as the exponential, Weibull, log-normal, and gamma distributions. Some properties, including the characteristics of failure rates of these distributions, are presented. We use a Bayesian approach for model selection and parameter estimation procedures. A well-known measure, called the Bayes factor, is used to find the most plausible model among several contending models. The posterior mean can be used as a parameter estimate for unknown parameters, once a model with the highest posterior probability is selected. Extensive simulation studies are performed to demonstrate our methodologies.

송전용 실리콘 폴리머애자의 산불영향 신뢰성 평가( I )

최인혁,이동일,정용운,유근양,Choi, In-Hyuk,Lee, Dong-Il,Chung, Yong-Woon,Yu, Kun-Yang 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.11

Most overhead transmission lines in Korea run over the mountain; however, only little study has been made for the effect of mountain fire on polymeric insulator for transmission lines, though the study is significantly required, Therefore, in this study, the authors observed the deformation of the sheds of the insulator under fire, varying the ignition time using artificial ignition testing equipment, and investigated electrical and mechanical characteristics of the insulator through dry withstand voltage test, impulse flashover test and tensile load test. As the results of the tests, the following conclusions were obtained, First, when the insulator was subjected to the fire, the electrical characteristics were slightly reduced, but there was no change on the mechanical characteristics, Secondly, the sheds and sheath of the insulator were not non-flammable but less-flammable. These two results show the high mechanical stability and durability of the insulator under severe fire condition, though the electrical characteristics can be deteriorated as the time that the insulator is subjected to fire, goes by.