• 제목/요약/키워드: stimuli-responsive system

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Tunable Photonic Band Gap Materials and Their Applications

  • 강영종
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.261-261
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    • 2010
  • Photonic band gap (PBG) materials have been of great interest due to their potential applications in science and technology. Their applications can be further extended when PBG becomes tunable against various chemical and electrical stimuli. In recent, it was found that tunable photonic band gap materials can be achieved by incorporating stimuli-responsive smart gels into PBG materials. For example, the characteristic volume phase transition of gels in response to the various external stimuli including temperature, pH, ionic strength, solvent compositions and electric field were recently combined with the unique optical properties of photonic crystals to form unprecedented highly responsive optical components. Since these responsive photonic crystals are capable of reversibly converting chemical or electrical energy into characteristic optical signals, they have been considered as a good platform for label-free chemical or biological detection, actuators or optical switches as well as a model system for investigating gel swelling behavior. Herein, we report block copolymer photonic gels self-assembled from polystyrene-b-poly (2-vinyl pyridine) (PS-b-P2VP) block copolymers. In this talk, we are going to demonstrate that selective swelling of lamellar structure can be effectively utilized for fabricating PBG materials with extremely large tunability. Optical properties and their applications will be discussed.

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항암제의 치료 효율성을 높이기 위한 다양한 자극 응답성 물질이 개질된 키토산 마이셀의 응용성 고찰 (Application of Stimuli-responsive Chitosan Micelles for Improved Therapeutic Efficiency of Anticancer Agents)

  • 정경원;박준규;나재운
    • 공업화학
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    • 제29권2호
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    • pp.147-154
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    • 2018
  • 현재 항암제의 낮은 치료 효율과 부작용을 해결하기 위해 고분자 기반의 약물전달체의 연구가 활발하게 진행되고 있다. 기존의 고분자기반의 약물 전달체는 우수한 결과를 보이는 등 상당한 진전이 있었음에도 불구하고, 대부분 혈중에서 안정성이 감소하여 표적 부위에 도달하기 전에 약물이 방출될 뿐만 아니라 오랜 시간 동안에 약물을 방출함으로써 부작용 및 낮은 치료 효율을 초래한다는 문제점을 가지고 있다. 본 총론에서는 이러한 비효율적인 약물 방출의 문제점을 개선하기 위한 방법으로 독성이 없고 생체 적합한 천연 고분자 키토산에 자극 응답성 물질을 도입하여 혈중에서 안정성을 높이고 표적 부위에서 약물을 과다 방출하여 치료 효율을 극대화할 수 있는 방법을 제시하고자 한다.

Spectral Properties of a pH Responsive Water Soluble Spironaphthoxazine and Its Multi-Switching Property

  • Bae, Jin-Seok;Kim, Sung-Hoon
    • 한국염색가공학회지
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    • 제25권1호
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    • pp.18-24
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    • 2013
  • A water soluble spironaphthoxazine (SPO) was synthesized, and its spectral properties were determined. Under UV irradiation, colorless SPO shows intensive blue color while the intensity of its initial fluorescence decreased. In addition, SPO also exhibited high sensitivity to pH stimuli both in colorimetry and fluorometry distinguishing from the spectral appearance observed under UV irradiation. Further, integrating these two optical characteristics a three-state switching system can be established, and all interconversions can be observed by naked-eye.

사용자 감정 예측을 통한 상황인지 추천시스템의 개선 (Improvement of a Context-aware Recommender System through User's Emotional State Prediction)

  • 안현철
    • Journal of Information Technology Applications and Management
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    • 제21권4호
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    • pp.203-223
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    • 2014
  • This study proposes a novel context-aware recommender system, which is designed to recommend the items according to the customer's responses to the previously recommended item. In specific, our proposed system predicts the user's emotional state from his or her responses (such as facial expressions and movements) to the previous recommended item, and then it recommends the items that are similar to the previous one when his or her emotional state is estimated as positive. If the customer's emotional state on the previously recommended item is regarded as negative, the system recommends the items that have characteristics opposite to the previous item. Our proposed system consists of two sub modules-(1) emotion prediction module, and (2) responsive recommendation module. Emotion prediction module contains the emotion prediction model that predicts a customer's arousal level-a physiological and psychological state of being awake or reactive to stimuli-using the customer's reaction data including facial expressions and body movements, which can be measured using Microsoft's Kinect Sensor. Responsive recommendation module generates a recommendation list by using the results from the first module-emotion prediction module. If a customer shows a high level of arousal on the previously recommended item, the module recommends the items that are most similar to the previous item. Otherwise, it recommends the items that are most dissimilar to the previous one. In order to validate the performance and usefulness of the proposed recommender system, we conducted empirical validation. In total, 30 undergraduate students participated in the experiment. We used 100 trailers of Korean movies that had been released from 2009 to 2012 as the items for recommendation. For the experiment, we manually constructed Korean movie trailer DB which contains the fields such as release date, genre, director, writer, and actors. In order to check if the recommendation using customers' responses outperforms the recommendation using their demographic information, we compared them. The performance of the recommendation was measured using two metrics-satisfaction and arousal levels. Experimental results showed that the recommendation using customers' responses (i.e. our proposed system) outperformed the recommendation using their demographic information with statistical significance.

하반신마비 환자의 보행기능 제어를 위한 FES하드웨어 시스템 설계에 관한 연구 (A Study on Design of FES Hardware System for Walking of Paraplegics)

  • 김근섭;김종원
    • 대한의용생체공학회:의공학회지
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    • 제12권1호
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    • pp.1-7
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    • 1991
  • This paper describes and discusses the employment of HMG pattern analysis to provide upper-motor-neuron paraplegics with patient-responsive control of FES ( functional electrical stimulation) for the purpose of walker-supported walking. The use of above-lesion EMG signals as a solution to the control problem is considered. The AR(autoregressive)parameters are identified by time-varying nonstationary Kalman filler algorithm using DSP chip and classified by fuzzy theory. The control and stimuli part of the below-lesion are based on micro-processor(8031). The designed stimulator is a 4-channel version. The experiments described above have only attempted to discriminate between standing function and sit-down function A further advantge of the this system Is applied for motor rehabilitation of social readaption of paralyzed humans.

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금속 이온에 대한 염료 로택산의 선택적 반응성 (Selective Response of Dye Rotaxane to Metal Ions)

  • 박종승
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2011년도 제44차 학술발표회
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    • pp.35-35
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    • 2011
  • The design and preparation of novel dye rotaxanes have gained much interest recently, since such structure usually exhibits peculiar spectral and optical changes. In spite of the promising results to date, increasing pressure remains to develop novel supramolecular structures based on stimuli-responsive systems. This presentation covers the study of inclusion complexes of cyclodextrins and various chromophores, with an emphasis on our most recent outcome of anisotropic hydrogel. In this system, physical gelation prepared from simple mixture of CD and a azo dye is completed through specific host-guest interaction. The obtained hydrogel exhibits respective morphological transitions based on supramolecular assembly and dissociation, leading to either precipitation or a sol-to-gel transition. It can identify different classes of metal ions, and, among them, naked-eye differentiation of lead ion is possible due to the coordination-induced unthreading of dye molecules. Accompanying structural changes were verified by numerous characterization techniques, including 2D-ROESY, HR-MAS, UV-Visible absorption, small-angle X-ray scattering, and induced circular dichroism measurements. Such properties discussed here will find useful in analytical applications, such as metal ion sensing and removal applications.

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하반신 마비 환자의 보행을 위한 근전도 제어 FES 시스템 구현에 관한 연구 (A Study of EMG-Controlled FES System Implementation for primitive-walking of Paraplegics)

  • 김근섭;김규학;김종원;홍완희;김성환
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1991년도 춘계학술대회
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    • pp.34-38
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    • 1991
  • This paper describes and discusses the employment of EMG pattern analysis to provide upper-motor-neuron paraplegics with patient-responsive control of FES (functional electrical stimulation) for the purpose of walker-supported walking. The use of above - lesion EMG signals as a solution to the control problem is considered. The AR (autoregressive) parameters are identified by Kalman filter algorithm using DSP chip and classified by fuzzy theory. The control and stimuli part of the below-lesion are based on microprocessor(8031). The designed stimulator is a 4-channel version. The experiments described above have only attempted to discriminate between standing function and sit-down function. A further advantage of the this system is applied for motor rehabilitation of social readaption of paralyzed humans.

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소청용탕이 기관지천식 환자의 폐기능과 삶의 질에 미치는 영향 (The Effects of Sochongryong-tang on Pulmonary Function and Quality-of-Life in Asthmatic Patients)

  • 허태석;황우석;주창엽;정희재;이형구;정승기
    • 대한한의학회지
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    • 제22권4호
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    • pp.131-141
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    • 2001
  • Objectives : Asthma is a chronic inflammatory disorder in which the airway smooth muscle undergoes exaggerated constriction and is abnormally responsive to external stimuli and clinically manifests dyspnea, cough, and wheezing. Recently in Korea, the number of asthma patients has tended to increase as air pollution increases and new allergens appear. This study aimed to identify the therapeutic effects of Sochongryong-tang, which has been used on asthmatic patients in Oriental Medicine for a long time. Methods : We studied 10 asthmatic patients who had visited the Division of Respiratory System, Department of Internal Medicine of Kyunghee Oriental Medical Center from February 1, 2001 to June 30, 2001, which examined the patients by the pulmonary function test (PFT) and Quality of Life Questionnaire for adult Korean Asthmatics (QLQAKA) before and after taking Sochongryong-tang for two weeks. The data was analyzed using paired t-test. Results : After treatment with Sochongryong-tang for two weeks, FEV 1.0 showed a significant increase of 14.2%, FVC a significant increase of 9.3% and PEFR a significant increase of 16.2% in results of patients examined asthmatic by PFT. In the results of QLQAKA, the mean of scores increased significantly over 0.5 points in total score, symptom domain, emotion domain, and environmental domain. Conclusions : This study shows that Sochongryong-tang has the effect of improvements of pulmonary function and quality of life in asthmatic patients.

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패러다임 전환에 의한 기업 측면의 IoT 경영 프로세스 구축방안 연구 (A Study on the establishment of IoT management process in terms of business according to Paradigm Shift)

  • 정민의;유성진
    • 지능정보연구
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    • 제21권2호
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    • pp.151-171
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    • 2015
  • 본 연구는 최근 가장 큰 이슈로 떠오르는 "사물인터넷(IoT: Internet of Things)"의 개념과 국내 외 IoT 시장에 대한 현황을 고찰하였으며, IoT 시대의 도래로 인해 유발되는 패러다임 전환 발생에 따른 기업측면의 적절한 대응방안에 대한 해결책을 도출하였다. 따라서 본 연구는 티핑포인트(Tipping point)에 있는 IoT 경쟁 시대에 적절하게 대응하기 위한 기업의 경영전략을 '패러다임 전환(paradigm shift)'이라는 시각을 통해 대응 방안을 제시하였다. 특히, 과거의 경영 패러다임과 IoT 시대의 경영 패러다임을 비교 분석하여 i)지식 및 학습 주도 경영, ii)기술 및 혁신 중심 경영, iii)수요 창출 경영, iv)글로벌 협업 경영으로 새롭게 패러다임 전환(Paradigm Shift)이 발생할 것으로 예측 및 제안하였고, 이러한 패러다임의 전환에 대응하기 위한 기업측면의 경영전략 프로세스 모델을 구축하기 위해 Gartner가 제시한 'RTE Cyclone model'을 활용하였다. '실시간 기업(RTE)' 이라는 개념은 급변하는 IoT 시대에 기업측면의 경영 전략 프로세스로 활용가치가 있다고 판단되며, 본 연구에서 적절히 응용하여 'IoT-RTE Cyclone model'을 제안하였다. 특히, 제안한 모델은 기업의 민첩성을 강조하고 IT 및 IoT 기술을 통한 실시간 모니터링, 분석, 실행을 기본으로 하며, 기업의 경영 프로세스 각 부문을 통합시켜 기업의 전반적인 서비스를 지원하기 때문에 빠르게 변화하는 IoT 시대에서 영위하는 기업측면에서의 효과적인 대응전략으로 활용할 수 있다.