• International Journal of Automotive Technology
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• 제8권1호
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• pp.27-31
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• 2007

The number of vehicles employing diesel engines is rapidly rising. Accompanying this trend, application of an after-treatment system is strictly required as a result of reinforced exhaust regulations. The Diesel Particulate Filter (DPF) system is considered as the most efficient method to reduce particulate matter (PM), but the improvement of a regeneration performance at any engine operation point presents a considerable challenge by itself. Therefore, the present study evaluates the effect of fuel injection characteristics on regeneration performance in a DOC and a catalyzed CR-DPF system. The temperature distribution on the rear surface of the DOC and the exhaust gas emission were analyzed in accordance with fuel injection strategies and engine operating conditions. A temperature increase more than BPT of DPF system was obtained with a small amount fuel injection although the exhaust gas temperature was low and flow rate was high. This increase of temperature at the DPF inlet cause PM to oxidize completely by oxygen. In the case of multi-step injection, the abrupt temperature changes of DOC inlet didn't occur and THC slip also could not be observed. However, in the case of pulse type injection, the abrupt injection of much fuel results in the decrease of DOC inlet temperatures and the instantaneous slip of THC was observed.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1998년도 추계학술발표 논문집
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• pp.225-229
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• 1998

The purpose of the current study was comparative analysis of autonomic and electrocortical responses to passive and active touch of the tektites with different subjective emotional preference. Perspective goal of the project is development of a template for classification of tactile stimuli according to subjective comfort and associated physiological manifestations. The study was carried out on 36 female college students. Physiological signals were acquired by Grass and B10PAC 100 systems with AcqKnowledge III software. Frontal, parietal and occipital EEG (relative power spectrum /percents/ of EEG bands - delta, theta, slow and fast alpha, low and fast beta), and autonomic variables, namely heart rate (HR), respiratory sinus arrhythmia (RSA), pulse transit time (PTT), respiration rate (RSP) and skin conductance parameters (SCL, amplitude, rise time and number of SCRs) were analyzed for rest baseline and stimulation conditions. Analysis of the overall pattern of reaction indicated that autonomic response to tactile stimulation was manifested in a form of moderate HR acceleration, RSP increase, RSA decrease (lowered vagal tone), decreased n and increased electrodermal activity (increased SCL, several SCRs) that reflects general sympathetic activation. Parietal EEG effects (on contra-lateral side to stimulated hand) were featured by short-term alpha-blocking, slightly reduced theta and significantly increased delta and enhanced fast beta activity with few variations across stimuli. The main finding of the study was that most and least preferred textures exhibited significant differences in autonomic (HR, RSP, PTT, SCR, and at less extent in RSA and SCL) and electrocortical responses (delta, slow and fast alpha, fast beta relative power). These differences were recorded both in passive and active stimulation modes, thus demonstrating reproducibility of distinction between most and least emotionally preferred tactile stimuli, suggesting influence of psychological factors, such as emotional property of stimulus, on physiological outcome. Nevertheless, development of sufficiently sensitive .and reliable template for classification of emotional responses to tactile stimulation based on physiological response pattern may require more extensive empirical database.

• 동의생리병리학회지
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• 제23권3호
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• pp.534-539
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• 2009

Deficiency and excess pattern differentiation is unique characteristic of traditional oriental medicine on diagnosis and treatment. This differentiation is accomplished through pulse, tongue diagnosis and question examination, but most of these processes need to be objectified for efficacious treatment and traditional medicine development. In this study, we developed the deficiency and excess pattern questionnaire for objectification of question examination. The deficiency and excess pattern questionnaire was made out through The Traditional Oriental Medical Literature with Delphi Technique. Patients who visited oriental medical hospital filled out the questionnaire by themselves. Diagnosis of deficiency and excess pattern are conducted separately by oriental medical doctors with more than 5 years' clinical experience. Various physical condition factors were derived for the deficiency and excess pattern questionnaire. (Ordinary health degree, pain pattern, fatigue, weight change, sweating, uncomfortable awareness on chest and abdomen) Deficiency symptoms group acquired internal consistency, but excess symptoms group did not. (Cronbach's ${\alpha}$ > 0.6) There were significant associations between doctor's diagnosis and deficiency and excess symptoms in 'ordinary heath degree', 'voice weakening', and 'chest distress' (p-value < 0.1) There were significant differences between deficiency and excess syndrome patients groups in deficiency questionnaire score but there were no significant differences between deficiency and excess syndrome patients groups in excess questionnaire score. We acquired the internal consistency and significant result of deficiency pattern questionnaire, but we can find out some difficulties in development of the excess pattern questionnaire. These difficulties are associated with insufficiency description of traditional literature and small number of patients diagnosed as excess pattern.

• 비파괴검사학회지
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• 제36권6호
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• pp.490-495
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• 2016

펄스와전류탐상에서 탐상 신호는 주로 센서코일에 유도되는 기전력의 시간에 따른 변화를 측정하여 사용되었는데, 최근에는 홀센서(Hall sensor)로 측정한 신호를 사용하는 경우도 많아지고 있다. 본 논문에서는 펄스와전류탐상에서 나타나는 홀센서 신호를 수치적으로 모델링하여 예측하였다. 이를 위해 두께 측정을 위한 탐촉자를 설계하고 먼저 계단입력전류를 사용한 수치해석을 수행하여 홀센서를 사용하였을 경우의 신호를 예측하였다. 또한, 코일을 센서로 사용하였을 경우의 신호도 동시에 계산하였다. 수치모델링 결과로 예측된 홀센서 신호들은 실험 연구를 통해 보고된 신호들과 유사한 형태를 가지고 있음을 확인할 수 있었다. 그리고 피검사체의 두께 변화에 따른 두 신호들의 특성을 분석하고 비교해 본 결과, 홀센서 신호에서는 코일센서 신호에 비해 두께 변화를 판별하기 위한 정보가 더 적게 제공된다는 것을 알 수 있었다. 펄스입력전류를 사용한 경우의 탐상 신호들도 계산해 본 결과, 두 신호 모두 사용된 펄스의 폭이 지난 시간에는 계단입력전류를 사용한 경우의 응답이 반대가 되어 감소하는 형태로 나타난다는 것을 확인할 수 있었다.

• Progress in Superconductivity
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• 제4권1호
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• pp.42-47
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• 2002

Measuring magnetic fields with a SQUID sensor always requires preliminary adjustments such as optimum bas current determination and flux-locking point search. A conventional magnetoencephalography (MEG) system consists of several dozens of sensors and we should condition each sensor one by one for an experiment. This timeconsuming job is not only cumbersome but also impractical for the common use in hospital. We had developed a serial port communication protocol between SQUID sensor controllers and a personal computer in order to control the sensors. However, theserial-bus-based control is too slow for adjusting all the sensors with a sufficient accuracy in a reasonable time. In this work, we introduce programmatic control sequence that saves the number of the control pulse arrays. The sequence separates into two stages. The first stage is a function for searching flux-locking points of the sensors and the other stage is for determining the optimum bias current that operates a sensor in a minimum noise level Generally, the optimum bias current for a SQUID sensor depends on the manufactured structure, so that it will not easily change about. Therefore, we can reduce the time for the optimum bias current determination by using the saved values that have been measured once by the second stage sequence. Applying the first stage sequence to a practical use, it has taken about 2-3 minutes to perform the flux-locking for our 37-channel SQUID magnetometer system.

• 감성과학
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• 제1권2호
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• pp.13-22
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• 1998

The sense of touch has both objective and subjective characteristics. During hand evaluation of the fabrics. psycho physiological processes such as emotion and stimulation. On other site, the mode of touch (passive vs. active) is also capable to modulate somatosensory responses. I.e., suppress somatocensory perception during active electrocortical responses to passive and active touch of the textiles with different subjective emotional preference. The study was carried out on 36 female college students. Physiological signals were acquired by Grass and BIOPAC 100 systems with AcqKnowledge variables, namely heart rate (HR), respiratory sinus arrhythmia (RSA), pulse transit time (PTT), respiration rate (RSP) and skin conductance parameters (SCL, amplitude, risetime and number of SCRs) were analyzed for baseline and stimulation conditions. Analysis was manifested in a form of moderate HR acceleration. RSP increase, RSA decrease (lowered vagal tone), decreased PTT and increased electrodermal activity (increased SCL, several SCRs) that reflects general sympathetic activation. Parietal EEG effects (on contra-lateral side to stimulated hand)were featured by short-term alpha-blocking, slightly reduced theta, significantly increased delta and enhanced fast beta activity with few variations across stimuli. The main finding of the study was that most and least preferred textures exhibited significant differences in autonomic (HR, RSP, PTT, SCR, and at less extent in RSA and SCL) and electrocortical responses (delta, slow and fast alpha, fast beta relative power). These differences were recorded both in passive and active stimulation modes, thus demonstrating reproducibility of distinction between most and least emotionally preferred tactile stimuli, suggesting influence of psychological factors, such as emotional property of stimulus, on physiological outcome.

• Korean Chemical Engineering Research
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• 제46권6호
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• pp.1087-1094
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• 2008

본 연구는 활성탄을 사용한 n-hexane의 흡착공정에 있어서 분자수준에서 시작하여 공정단계에 이르는 다중규모 모사에 관하여 기술한다. 분자모사에서는 GCMC(Grand Canonical Monte Carlo) 방법을 이용하여 활성탄에서 n-hexane의 등온흡착식을 예측하고, 2차원 전산유체역학(CFD; Computational fluid dynamics) 모사를 통하여 흡착컬럼 내 유체흐름에 대한 수력학적 특성을 파악한다. 공정모사단계에서는 분자모사 및 유체역학 모사에서 각각 얻은 등온흡착식과 축방향 확산계수값을 이용하여 n-hexane의 용출곡선을 얻는다. 이러한 3단계 다중규모 모사기법을 활용하여 얻은 공정모사 결과는 펄스응답의 실험결과와 비교해볼 때, 온도와 유량변화에 따른 1차 모멘트(평균 체류시간)에 관하여 약 20% 미만의 오차범위에서 일치함을 확인할 수 있다. 이 결과로부터 분자수준에서 시작하는 다중규모 모사는 필요한 실험횟수를 줄이면서 흡착공정 개발을 가속화할 수 있는 가능성을 보여준다.

• 대한화학회지
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• 제33권5호
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• pp.496-503
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• 1989

란탄나이드 3가 (Pr(III)와 Yb(III))와 2,2,6,6-tetramethyl-3,5-heptanedione(dipivaloylmethane) 착물들의 전기화학적 거동을 DC와 DP 그리고 CV 방법으로 조사하였다. 란탄나이드 3가 착물들 중 Pr(III)의 환원은 Ag-AgCl 전극으로 Epc = -0.13 V와 -0.80 V 그리고 Yb(III)는 -0.02 Ⅴ로 1전자이동에 의한 것임을 알았고, 1차 화학평형반응이 가역과 비가역으로 진행되는 ErCr전극과정임을 DP와 CV로부터 알았다. 평형상수 lnK는 여러 용매들로부터 얻었고, 이들 상수는 용매의 유전상수가 감소함에 따라 증가됨을 알았다. 이들 반응에서 lnK는 여러 용매에 대한 ln(1/D)을 도시하면 좋은 직선관계에 있었고, 이 때 란탄나이드의 거동은 원자번호가 증가함에 따라서 lnK가 감소하였다.

• 동굴
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• 제76호
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• pp.37-42
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• 2006

The Dielectric Barrier Discharge (DBD) is a nonequilibrium gas discharge that is generated in the space between two electrodes, which are separated by an insulating dielectric layer. The dielectric layer can be put on either of the two electrodes or be inserted in the space between two electrodes. If an AC or pulse high voltage is applied to the electrodes that is operated at applied frequency from 50Hz to several MHz and applied voltages from a few to a few tens of kilovolts rms, the breakdown can occur in working gas, resulting in large numbers of micro-discharges across the gap, the gas discharge is the so called DBD. Compared with most other means for nonequilibrium discharges, the main advantage of the DBD is that active species for chemical reaction can be produced at low temperature and atmospheric pressure without the vacuum set up, it also presents many unique physical and chemical process including light, heat, sound and electricity. This has led to a number of important applications such as ozone synthesizing, UV lamp house, CO2 lasers, et al. In recent years, due to its potential applications in plasma chemistry, semiconductor etching, pollution control, nanometer material and large area flat plasma display panels, DBD has received intensive attention from many researchers and is becoming a hot topic in the field of non-thermal plasma.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
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• pp.11-15
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• 1999

In order to evlauate feasibility of the gene tagging by the maize transposable element Ac in heterologous plant systems, we have investigated physical distances and directions of transposition of the element in Arabidopsis thaliana and tobacco cultured cell line BY-2. We prepared a T-DNA construct that carried a non-autonomous derivative of Ac with a site for cleavage by endonuclease I-Scel (designated dAc-I-RS element). Another cleavage site was also introduced into the T-DNA region outside dAc-I-RS. A number of transgenic Arabidopsis plants were generated, each of which had a single copy of the T-DNA at a different chromosomal location. To examine the pattern of transposition, three out of these transgenic plants were crossed with the Arabidopsis plant that carried the gene for Ac transposase and progeny in which dAc-I-RS had been transposed were isolated. After digestion of the genomic DNA of these progeny with I-SceI, sizes of segment of DNA were determined byd pulse-field gel electrophoresis. We also performed linkage analysis for the transposed elements and sites of mutations near the elements. Our results with three transgenic lines showed that 50% of all transposition events had occurred within 1,700 kilo-base pairs (kb) on the same chromosome, with 35% within 200 kb, and that the elements transposed in both directions on the chromosome with roughly equal probability. The data thus indicate that the Ac-Ds system is most useful for tagging of genes that are present within 200 kb of the chromosomal site of Ac in Arabidopsis. In addition, determination of the precise localization of the transposed dAc-I-RS element should definitely assist in map-based cloning of genes around insertion sites. In the present paper, we report typical examples of such gene isolation studies.