• 한국의류학회지
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• 제45권1호
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• pp.106-122
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• 2021

This study confirmed the mechanical properties of an auxetic re-entrant pattern prepared using 3D printing technology and its composite fabric with neoprene for the production of functional auxetic patterns/textiles for safety shoes. Samples were prepared by the tilt angle of a re-entrant pattern of 0°, 30°, 45°, 60° and 90°, and then analyzed using Poisson's ratio, bending, compression, and tensile properties. A 3D printed auxetic re-entrant pattern (3DP-RE) and its composite fabric (3DP-RE/NP) showed a negative Poisson's ratio in all tilting angles that indicated auxetic properties. The results of the bending property shown that strength of 3DP-RE/NP was 1.5 times lower than NP, but the strain improved 2.0 times. It was confirmed that the deformation of 3DP-RE/NP is possible with a low load. Each sample type of compression behavior indicated similar regardless of the tilting angles; in addition, the compression toughness of 3DP-RE/NP increased 1.2 times compared with NP. In the case of tensile properties, 3DP-RE and 3DP-RE/NP were affected by the tilting angle, samples with 90° (the opposite of load direction) showed best tensile property and toughness. 3DP-RE/NP indicated improved bending, compression, and tensile properties.

• 한국정밀공학회지
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• 제23권7호
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• pp.168-176
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• 2006

Nowadays, Three dimensional printing (3DP) technique that is one of solid freeform fabrication (SFF) technology has been notable issue, and has been applied by various fields. The SFF system can fabricate three dimensional objects of solid freeform with high speed and low cost using ink jet printing technology. In this research, a SFF system to analyze 3DP process technology is developed. We applied sliding mode control with sliding perturbation observer (SMCSPO) algorithm and minimized position error to the developed SFF system. We analyzed and optimized process variables such as jetted volume, layer thickness, powder bed and so on experimentally. Also. the dimensional error of a developed SFF system is evaluated. Finally, the feasibility of application to bio manufacturing is presented through successful fabrication of teeth and cranium model.

• 대한전자공학회논문지SP
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• 제41권3호
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• pp.201-207
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• 2004

본 논문은 연속음 인식에 관한 연구로써, 구문 분석을 이용한 One-Stage DMS/DP에 의한 음성 인식 방법을 사용한다. 인식 실험을 위해 우선 구간 구분화 알고리즘을 이용하여 DMS(dynamic Multi-Section) 모델을 만들며, 구문 분석을 이용한 One-Stage DMS/DP 방법으로 연속음 데이터를 인식하게 하였다. 제안된 방법에 의한 인식 실험을 수행하는 것 외에도 비교를 위해 전통적인 One-Stage DP 방법을 같은 조건 같은 데이터를 가지고 수행하였다. 인식 실험 결과, 기존의 방법보다 구문분석을 이용한 One-Stage DMS/DP 방법이 우수한 것으로 나타났다.

• 대한의생명과학회지
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• 제18권4호
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• pp.435-437
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• 2012

House dust mite (HDM) is important in the pathogenesis of allergic diseases including asthma and atopic dermatitis. Dermatophagoides pteronissinus (Dp) is one of major HDM allergens. In this study, we investigated that Dp extract (DpE) affects on the chemotactic activity of monocytes isolated from the peripheral blood. DpE inhibited the migration of human monocytes in response to CC chemokines such as MIP-$1{\alpha}$, RANTES, HCC-4, MCP-1, and TARC. DpE did not alter the expression of CC chemokine receptors (CCRs) such as CCR1, CCR2, CCR3, CCR4, and CCR5. These results indicate that DpE blocks the chemotaxis of human monocytes and its mechanism is not involved in alteration of CCR expression. Better understanding of the effect of DpE on monocytes will enable elucidation of the role of Dp in the development of allergic diseases.

• 한국음향학회지
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• 제14권3호
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• pp.97-104
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• 1995

본 논문은 음성 다이얼링 시스템 구현을 위한 연속 숫자음 인식에 관한 연구로써, 구문 분석을 이용한 One-Stage DP에 의한 음성 인식 방법을 제안하다. 인식 실험을 위해 우선 구간 구분화 알고리즘을 이용하여 DMS (Dynamic Multi-SEction) 모델을 만들며, 제안된 구문 분석을 이용한 One-Stage DP 방법으로 실험 대ㅛ상의 연속 숫자음 데이터를 인식하게 하였다. 본 연구에서는 8명의 ㅣ남성 화자에 의해 2-3번 발음도니 21종의 7자리의 연속 숫자음이 사용되었고, 기존의 One-Stage DP와 제안된 구문 분석을 이용한 One-Stage DP 음성 인식 알고리즘을 사용해서 화자 종속과 화자 독립 실험을 실험실 환경에서 수행하였다. 인식 실험 결과, 기존의 방법보다 제안된 방법이 인식률이 좋은 것으로 나타났으며, 제안된 방법에서는 화자 종속과 화자 독립 실험에서 각각 약 91.7%, 89.7%로 나타났다.

• 한국의류학회지
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• 제26권12호
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• pp.1749-1755
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• 2002

본연구의 목적은DP가공에 의한 가교화를 통해 텐셀의 피브릴화를 조절할 때 DP가공 방법 및 NaOH전처리 효과를 물성, 표면형태, 역학적 성질 및 태의 변화의 관점에서 고찰하는데 있다. SEM 분석결과DP가공에 의해 피브릴 발생 정도는 감소하였다. DP가공 방법에 있어 서 WF법과 PDC법에 따른 물성의 차이는 나타나지 않았다. 역학적특성의 경우 DP가공은 DP가공 방법에 상관없이 효소처리한 직물의 인장선형성에는 큰 영 향을 주지 않았으나 인장에 너지, 굽힘 강성, 압축선형성, 압축 레질리언스, 기하학적 거칠기는 감소시켰고 인장 레질리언스, 굽힘이력, 압축에너지는 증가시켰다. 전단특성은 WF법에서는 증가한 반면, PDC법에서는 감소하여 DP가공 방법에 따른 차이를 나타내었다. WF법이 PDC법보다 더 높은 Koshi, Numeri, Fukurami 값을 보였으며, 종합태 값은 비슷하게 나타났다. NaOH 전처 리에 의해 수지부착량은 감소하였으나 감량률은 증가하였으며, DP성/물성은 더 낮게 나타났다. NaOH 전처리에 의해 인장선형성, 인장에너지, 압축 레질리언스, 전단 및 굽힘특성은 증가하였으나 인장레질리언스와 압축선형성, 압축에너지, 표면특성은 감소하였다. NaOH 전처리한 경우 Koshi는 증가하였고, Numrei와 Fukuramil는 감소하였으며, 종합태 값은 가장 낮았다. 처리한 시료들은 각각 다른 감성과 촉감을 나타냈다.

• 한국식품과학회지
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• 제21권1호
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• pp.80-85
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• 1989

겉보리와 쌀보리의 전분 및 이들의 구성성분인 아밀로오스와 아밀로펙틴의 분자 구조적 성질을 비교 검토하였다. 쌀보리의 전분 및 아밀로오스와 아밀로펙틴의 ${\beta}-amylosis\;limit(%)$는 각각 56.3, 87 및 52% 이었고, 겉보리 58.6, 77.7 및 57.6%이었다. 쌀보리 아밀로펙틴의 outer chain length${\overline{OCL})$과 inner chain length ${\overline{ICL}}$을 각각 15.8 및 7.8 이었고 겉보리는 각각 17.0 및 7.8이었고, 두 chain 길이의 비는 각각 약 2.1:1 및 2.0:1이었다. 두 시료 전분 모두 pullulanase 로 debranching 한 후의 Sephadex G-75에 의한 용출곡선의 양상은 ${\overline{dp}}55$ 이상의 아밀로오스 성분을 나타내는 분획과 아밀로펙틴 성분으로 볼 수 있는 ${\overline{dp}}35-45$ 및 ${\overline{dp}}10-20$의 bimodal 분포를 갖는 분획 특징을 나타내었다. 또 debranching과 동시에 ${\beta}-amylase$로 처리한 경우는 가수분해 되지 않는 ${\overline{dp}}55$ 이상의 분획성분이 $0.3{\sim}1.5%$ 존재하였다. 아울러 ${\beta}-amylase$로만 가수분해한 경우도 시료차이 없이 ${\overline{dp}}\;55$ 이상의 ${\beta}-limit\;dextrin$ 성분과 ${\overline{dp}}\;10$ 이하의 과당성분으로 분획되는 비슷한 분획양상을 보였으나 분획성분의 분자량 분포사이에는 현저한 시료 차이를 나타내었다.

• 대한한방소아과학회지
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• 제24권3호
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• pp.106-120
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• 2010

Objectives: Sanjointang has been clinically used much for treating sleeplessness. However, the effects of Sanjointang in artificial sleep deprivation situations are not known. The purpose of this study is to evaluate the heart rate, left ventricular systolic pressure, left ventricular diastolic pressure, +dp/dt maximum, -dp/dt maximum, and -dp/dt / +dp/dt ratio which are related to the hemodynamic functions of the heart by using sleep-deprived Sparague-Dawley rats, in order to clarify the impact of Sanjointang on hemodynamic functions of the heart of sleep deprived rats. Methods: Eighteen hearts were removed from the male Sparague-Dawley rats weighting about 180g were perfused by the Langendorff technique with modified 37 Krebs-Henseleit's buffer solution at a constant perfusion pressure (60mmHg). They were randomly assigned to one of the following three groups, 1) Normal group (those which did not have sleep deprivation and received normal saline administration), 2) Control group (sleep deprived and normal saline administered), 3) Sample group (sleep deprived and Sanjointang was administered). Control and sample groups rats were deprived 96 hours of sleep by using the modified multiple platform technique. Heart rate, left ventricular systolic pressure, left ventricular diastolic pressure, +dp/dt maximum, -dp/dt maximum, -dp/dt / +dp/dt ratio were evaluated at baseline after the administration of either normal saline or Sanjointang. Results: The heart rate and -dp/dt / +dp/dt ratio was significantly decreased in rats with 96 hours of sleep deprived significantly decreased. The change in the heart rate after administering Sanjointang did not show any significant difference. The left ventricular systolic pressure of the removed heart significantly decreased due to Sanjointang administration, while the left ventricular diastolic pressure significantly increased (p<0.05). The +dp/dt maximum and -dp/dt maximum both significantly decreased in the removed heart after administering Sanjointang. (p<0.05). There was no significant difference observed in the -dp/dt / +dp/dt ratio after administering Sanjointang. Conclusions: According to the results above, sleep deprivation significantly decreases heart rate and -dp/dt / +dp/dt ratio. This is considered as a result of exhaustion due to accumulation of fatigue. Meanwhile, Sanjointang reduced left ventricular systolic pressure and raised left ventricular diastolic pressure, and relieved the contractility and relaxation of the myocardium. Consequently, this reduces the burden of the heart and creates a relatively stabilized heart condition similar to a sleeping condition.

• Korean Journal of Radiology
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• 제22권8호
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• pp.1266-1278
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• 2021

Objective: We aimed to compare the aortic valve area (AVA) calculated using fast high-resolution three-dimensional (3D) magnetic resonance (MR) image acquisition with that of the conventional two-dimensional (2D) cine MR technique. Materials and Methods: We included 139 consecutive patients (mean age ± standard deviation [SD], 68.5 ± 9.4 years) with aortic valvular stenosis (AS) and 21 asymptomatic controls (52.3 ± 14.2 years). High-resolution T2-prepared 3D steady-state free precession (SSFP) images (2.0 mm slice thickness, 10 contiguous slices) for 3D planimetry (3DP) were acquired with a single breath hold during mid-systole. 2D SSFP cine MR images (6.0 mm slice thickness) for 2D planimetry (2DP) were also obtained at three aortic valve levels. The calculations for the effective AVA based on the MR images were compared with the transthoracic echocardiographic (TTE) measurements using the continuity equation. Results: The mean AVA ± SD derived by 3DP, 2DP, and TTE in the AS group were 0.81 ± 0.26 cm², 0.82 ± 0.34 cm², and 0.80 ± 0.26 cm², respectively (p = 0.366). The intra-observer agreement was higher for 3DP than 2DP in one observer: intraclass correlation coefficient (ICC) of 0.95 (95% confidence interval [CI], 0.94-0.97) and 0.87 (95% CI, 0.82-0.91), respectively, for observer 1 and 0.97 (95% CI, 0.96-0.98) and 0.98 (95% CI, 0.97-0.99), respectively, for observer 2. Inter-observer agreement was similar between 3DP and 2DP, with the ICC of 0.92 (95% CI, 0.89-0.94) and 0.91 (95% CI, 0.88-0.93), respectively. 3DP-derived AVA showed a slightly higher agreement with AVA measured by TTE than the 2DP-derived AVA, with the ICC of 0.87 (95% CI, 0.82-0.91) vs. 0.85 (95% CI, 0.79-0.89). Conclusion: High-resolution 3D MR image acquisition, with single-breath-hold SSFP sequences, gave AVA measurement with low observer variability that correlated highly with those obtained by TTE.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.58-58
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• 2000

As many sensors and actuators are used in various automated systems, the application of network system to real-time distributed control is gaining acceptance in many industries. In order to take advantages of the network technique. however, network implementation should be carefully designed to satisfy real-time constraints and to consider network delays. This paper presents the implementation of feedback control system in Profibus-DP. Profibus-DP is a type of fieldbus protocols that are specifically designed to interconnect simple devices with fast I/O data exchange. As feedback control in profibus-DP is implemented, Network delays is found with influence of system performance. We analyze network delays in Profibus-DP into 3 reasons - dead time in Profibus interface, protocol delay, delay by asynchronization. In order to compensate the network delays, we introduce control algorithms with time delay concept. The results show that network delay can be compensated.