• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1577-1578
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• 1997

We have studied the effect of the rubbing fabric for liquid crystal alignment and pretilt angle generation in nematic liquid crystals (NLC), 4-cyano-4-n-penthylbiphenyl (5CB), on rubbed polyimide (PI) surfaces. The pretilt angle of 5CB for nylon and rayon fabric is larger than that of cotton fabric in weak rubbing on rubbed PI surfaces. We conclude that the pretilt angle of 5CB is strongly related to the rubbing fabrics on rubbed PI surfaces.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1759-1761
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• 1999

The generation of pretilt in nematic liquid crystal(NLC)and electro-optical(EO) characteristics of photo-aligned twisted nematic (TN)-LCD with oblique p-polarized ultraviolet (UV) light irradiation on the two kinds of the soluble polyimide (PI) surfaces containing trifluoromethyl moieties were investigated. The generated pretilt angle of NLC is about $2.5^{\circ}$ with p-polarized UV light irradiation of $20^{\circ}$ on PI-3 surface at 20 min.; However pretilt angle of about $0.5^{\circ}$ are observed on PI-1 and PI-2 surfaces. The generated pretilt angle of NLC on PI-3 surface may be attributed to the trifluoromethyl moieties attached to the lateral benzene rings. The voltage-transmittance and response time characteristics of photo-aligned TN-LCD with p-polarized UV light irradiation of $20^{\circ}$ on PI-1 surfaceat at 20 min were almost same in comparison with the rubbing-aligned TN-LCD. However, the high threshold voltage and slow response are observed on PI-3 surface. Also, the decay time $\tau_d$ of photo-aligned TN-LCD is attributed to the anchoring energy of NLC.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.343-346
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• 1998

The generation of pretilt angle in nematic liquid crystal (NLC) and electro-optical (EO) characteristics of photo-aligned twisted nematic (TN)-LCD with oblique P-polarized ultraviolet (UV) light irradiation on the two kinds of the soluble polyimide (PI) surfaces containing trifluoromethyl moieties were investigated. The generated pretilt angle of NLC is about 2.5$^{\circ}$with P-polarized UV light irradiation of 20$^{\circ}$on PI-3 surface at 20 min.; However pretilt angle of about 0.5$^{\circ}$are observed on PI-1 and PI-2 surfaces. The generated pretilt angle of NLC on PI-3 surface may be attributed to the trifluoromethyl moieties attached to the lateral benzene rings. The voltage-transmittance and response time characteristics of photo-aligned TN-LCD with P-polarized UV light irradiation of 20$^{\circ}$on PI-1 surface at 20 min were almost same in comparison with the rubbing-aligned TN-LCD. However, the high threshold voltage and slow response are observed on PI-3 surface. Also, the decay time $\tau$$\sub$d/ of photo-aligned TN-LCD is attributed to the anchoring energy of NLC.

• Journal of Chest Surgery
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• 제27권5호
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• pp.364-373
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• 1994

Alpha 1-Proteinase inhibitor[PI] was known as a major protective enzyme against to excessive hydrolytic and proteolytic reaction. So, it was suggested that Alpha 1-PI may implicated in growth of bronchogenic cancer. This study was undertaken to investigate the role of Alpha 1-PI in local invasion of bronchogenic cancer. Three groups of patients were studied; Preliminary research group of 15 bronchogenic cancer patients, Main research group of 13 bronchogenic cancer patients and Normal control group of 10 nephrectomy donor. Serum Alpha 1-PI level was observed in each group of patients during pre-and postoperative days. Pre-operative serum Alpha 1-PI level in preliminary research group [329.2$\pm$14.21mg/dl]and main research group[406.2$\pm$39.30mg/dl] were higher than in normal control group[236.2$\pm$19.55mg/dl] significantly[p<0.005]. Serial Alpha 1-PI level in each group during pre-and postoperative days shows peaked at 3rd. postoperative day in preliminary and main research group, thereafter decreased gradually. Immunohistochemical study for Alpha 1-antitrypsin[A1AT] was carried out by ABC[avidin-biotin peroxidase complex] method using Alpha-1 antitrypsin DAKOR to tumor tissues of 13 lung cancer patients in main research group. 6 cases[46.2%, squamous cell ca.;5, adenocarcinoma;1] of above 13 cases show positive immunoreactivity for A1AT. In conclusion, alpha 1-PI and elastase are disclosed that have defined actions for lung cancer growing or spreading.

• 수면정신생리
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• 제19권2호
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• pp.68-76
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• 2012

목 적: 수면 장애는 자율신경계의 변화를 유발하여 심혈관계에 영향을 준다. 일차성 불면증(primary insomnia, 이하 PI)은 수면부족 및 각성으로, 폐쇄성 수면무호흡 증후군(obstructive sleep apnea syndrome, 이하 OSAS)은 수면 중 빈번한 각성, 저산소증 등으로 교감신경계 항진을 유발한다. 이에 OSAS와 PI 사이에서 심박동률 변이도(heart rate variability, 이하 HRV) 분석을 통해 자율신경계의 변화 정도를 비교하고자 하였다. 방 법: 임상병력 및 야간수면다원검사(nocturnal polysomnography, 이하 NPSG)로 선택된 PI와 OSAS 전체 315 명의 대상자 중 OSAS는 무호흡-저호흡 지수(apnea-hypopnea index, 이하 AHI)에 따라서 경도, 중등도, 중증도 OSAS로 분류하여 PI를 포함하여 4개의 군으로 분류되었다. 이후 연령, 성별, 군간 개체수를 고려하여 최종적으로 110명의 대상자가 선택되었고, PI군(평균나이 41.50, 표준편차 13.16, AHI <5, n=20), 경도 OSAS군(평균나이 43.67, 표준편차 12.11, AHI 5~15, n=30), 중등도 OSAS군(평균나이 44.93, 표준편차 12.38, AHI 16~30, n=30), 중증도 OSAS군(평균 나이 45.87, 표준편차 12.44, AHI >30, n=30)의 4개 군으로 나누었다. 이후 NPSG를 통해 얻은 각 군의 HRV 지수 비교를 위하여 연령과 체질량지수(body weight index, BMI)를 공변량으로 하여 공분산분석(analysis of covariance, ANCOVA)를 실시한 후 사후분석으로 Sidak test를 실시하였다. 결 과: HRV 지수의 비교 결과 PI군과 경도, 중등도의 OSAS군 간에 유의한 차이는 없었다. 그러나 PI군과 중증도 OSAS군 사이에는 유의한 차이가 있었다. 군간비교에서 통계적으로 가장 현저한 차이를 보인 PI군과 중증도 OSAS군에서 HRV 지수 중 통계적으로 의미 있는 각각의 값은 다음과 같았다. Average RR interval은 $991.1{\pm}27.1$과 $875.8{\pm}22.0$ ms(p=0.016), standard deviation of NN interval(SDNN)은 $85.4{\pm}6.6$과 $112.8{\pm}5.4$ ms(p=0.022), SDNN index는 $57.5{\pm}5.2$과 $87.6{\pm}4.2$(p<0.001), total power는 $11893.5{\pm}1359.9$과 $8097.0{\pm}1107.2ms^2$(p=0.008), very low frequency(VLF)는 $7534.8{\pm}1120.1$과 $11883.8{\pm}912.0ms^2$(p=0.035), low frequency(LF)는 $2724.2{\pm}327.8$과 $4351.6{\pm}266.9ms^2$였다(p=0.003). 결 론: 본 연구에서는 PI군에 비해 중증도의 OSAS군에서 HRV 지수 중 교감신경계의 영향을 많이 받는 VLF, LF 등이 상승하는 양상을 보였고, 이를 통해 PI에 비해 중증도의 OSAS가 교감신경계 활동증가에 보다 더 큰 영향을 끼치는 것을 알 수 있었다.

• 공업화학
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• 제18권5호
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• pp.483-489
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• 2007

Polyaniline (PANI)/Polyimide (PI) 혼합막을 제조하여 PANI 함량과 doping처리가 막의 구조적 특성과 기체 분리 특성에 미치는 영향을 연구하였다. NMP를 용매로 하여 6FDA와 ODA를 반응시켜 얻어진 polyamic acid (PAA) 용액과 PANI 용액을 혼합하여 PANI/PI 혼합막을 얻었다. 얻어진 PANI/PI 막을 1M의 HCl 수용액에서 24시간 doping처리하여 doped PANI/PI 혼합막을 제조하였다. 제조한 막은 FT-IR과 XRD 및 TGA에 의하여 구조적 특성을 분석하였고, $30^{\circ}C$와 5 atm에서 압력변화법으로 $H_2$, $O_2$, $CO_2$, $N_2$ 및 $CH_4$에 대한 기체 투과 특성을 조사하였다. PANI/PI 혼합막은 PANI와 PI의 흡수특성을 잘 보여주었고 PANI보다 열적 안정성이 향상되었으며, PANI의 함량이 증가할수록 d-spacing은 감소하였다. PANI/PI 혼합막에서 기체의 투과도계수는 PANI의 함량이 증가함에 따라 감소하였으며 투과도 계수의 크기는 $H_2$ > $O_2$ > $CO_2$ > $N_2$ > $CH_4$의 순서였다. PANI/PI막을 doping처리하면 투과도계수는 감소하나 투과선택도는 향상되었다. 특히 doping한 PANI/PI (75/25)막에서 $H_2/CH_4$의 선택도는 991을 나타내었다.

• 대한수의학회지
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• 제39권1호
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• pp.230-239
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• 1999

Digital color doppler ultrasonographic system(DCDUS) has a lot of diagnostic functions. One of these is a detection of low velocity vessels in the organs of abdominal cavity. The purpose of study was to determine the clinical usefulness of DCDUS. Interlobar artery resistive index(RI), pulsatility index(PI) and systolic diastolic ratio(SDr) were measured for diagnosis of obstructed urinary tract. RI, PI and SDr were a measure of intrarenal blood flow impedance. This study was consisted of 2 groups. The normal group was studied in 16 normal adult dogs and the study group was studied 7 dogs with surgically induced, unilateral ureteral obstruction. In the study group, parameters were checked in normal condition and on 1, 2, 3, 5, 7 and 10th day after ligation. The result were summarized as follows. In the normal group, RI, PI and SDr of the left kidney was $0.65{\pm}0.04$, $1.25{\pm}0.12$ and $292.45{\pm}29.40$, respectively. RI, PI and SDr of the right kidney were $0.64{\pm}0.05$, $1.28{\pm}0.20$ and $282.25{\pm}37.26$, respectively. In the study group, RI of the left kidney induced ligation was increased significantly on 1, 2, 3, 5, 7 and 10th day. RI of the left kidney on 1, 2, 3, 5, 7 and 10th day were $0.75{\pm}0.05$, $0.71{\pm}0.03$, $0.74{\pm}0.04$, $0.74{\pm}0.02$, $0.73{\pm}0.02$ and $0.73{\pm}0.04$, respectively. PI of the left kidney was increased significantly on 1, 3, 5 and 7th day. PI of the left kidney on 1, 3, 5 and 7th day were $1.57{\pm}0.21$, $1.54{\pm}0.24$, $1.60{\pm}0.15$ and $1.60{\pm}0.26$, respectively. SDr of the left kidney increased significantly on 1, 2, 3, 5 and 7th day. SDr of the left kidney on 1, 2, 3, 5 and 7th day were $412.18{\pm}86.69$, $352.14{\pm}47.05$, $399.77{\pm}65.54$, $369.43{\pm}48.34$ and $365.57{\pm}22.46$, respectively(p<0.05). In the study group, RI of the left kidney was more increased than that of the right kidney on 1, 2, 3, 5, 7 and 10th day. PI of the left kidney was more increased than that of the right kidney on 1, 3, 5, and 7th day. SDr of the left kidney was more increased than that of the right kidney on 1, 2, 3, 5 and 7th day(p<0.05). RI was effective in the diagnosis of an acute unilateral ureteral obstruction. PI and SDr were insufficient in the diagnosis of an acute unilateral ureteral obstruction.

• 동력기계공학회지
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• 제18권5호
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• pp.28-34
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• 2014

This paper deals with optimum PI controller design using genetic algorithm to improve control performance and robustness for an oil cooler system. The optimum PI gain was found to minimize an object function, integrated absolute error, and to satisfy control design specifications such as overshoot and settling time based on practical transfer function of the oil cooler system. The control performance and robustness were investigated by comparing indicial responses and Bode diagram analysis with respect to three kinds of PI gains obtained from different gain decision manners. Moreover, the robustness against to input disturbances, sinusoidal wave form and abrupt single pulse, was evaluated. The computer simulation results showed that the suggested optimum gain can establish desirable control performance and strong robustness with easy design process.

• 제어로봇시스템학회논문지
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• 제14권5호
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• pp.489-495
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• 2008

This paper offers a practical control scheme for driving mode transformation of a rescue robot already developed. The rescue robot, VSTR(Variable Single-Tracked Robot), has two driving modes, so can traverse untidy terrain and overcome obstacles such as stairs easily by use of timely driving mode transformation. Classical PI control scheme was used firstly for driving mode transformation, but stationary phenomenon, which might have a bad effect on the performance in real situation, came into existence. Therefore, we suggest a new controller, PI-based feedforward controller, which should be a good alternative for the problem, and compare it with other nonlinear control scheme.

• 제어로봇시스템학회논문지
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• 제12권5호
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• pp.505-508
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• 2006

This paper presents a new analytical approach for designing multiloop PI controllers for disturbance rejection in multivariable processes with time delay. The proposed method is based on IMC-PID design approach. To overcome a sluggish load response by dominant pole in the process, the IMC filter is modified to compensate the dominant pole effect. Based on the modified IMC filter, an analytical tuning rule for multiloop PI controller is driven by extending the generalized IMC-PID method for single input/single output (SISO) systems [1] to multi input/multi output (MIMO) systems. Simulation results show that the proposed method gives a satisfactory load performance as well as servo performance in the multiloop system.