• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.461-461
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• 2012

미생물 처리에 적용하기 위한 저주파 Dielectric Barrier Discharge (DBD) Plasma Device를 고안하였다. 현재 생의학적으로 광범위하게 사용되는 Plasma Jet Device는 가스를 주입해 주어야 한다. 그러나 Plasma Jet Device의 노즐로부터 배출되는 가스는 Media의 흔들림과 증발 유발시키며 미생물에게 영향을 미친다. 가스 배출에 의한 영향을 없애기 위해 가스 주입이 없는 Plasma 발생 장치를 제작 하고, 미생물에 적용하여 그 효과를 관찰하였다. 본 실험에 사용된 Plasma 발생 장치는 대기 중에서 방전된다. 가스의 주입 없이 낮은 방전 전압과 균일한 플라즈마의 발생을 위해 Plasma 발생 장치의 접지 전극으로 Mesh를 사용 하였다. 본 Plasma 발생 장치로 발생된 Plasma를 곰팡이(Fusariumgraminearum)에 조사한 결과, 조사 시간이 길어짐에 따라 배양된 곰팡이의 Colony 수가 Plasma를 조사하지 않은 경우에 비해 줄어드는 것을 확인할 수 있었다. 또한 각각의 곰팡이 Colony의 크기도 줄어들었다.

• Journal of Environmental Science International
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• v.33 no.3
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• pp.205-215
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• 2024

Antibiotics are substances produced by microorganisms that kill or inhibit and are essential for infectious diseases management. This study aimed to provide basic data for overcoming antibiotic resistance in the marine bacterium LJ-18. The API 20NE and API 50CH kits were used to identify this microorganism. Morphological, physiological, and biochemical properties were investigated using MacFaddin's manuals. Subsequently, isolated LJ-18 was found to belong to a genus of Streptomyces that forms mycelia. LJ-18 also grew well at 28-32℃ on modified Bennett's agar. To isolate and purify the antibacterial compound, LJ-18 culture was divided into ethyl acetate and distilled water fractions. Considerable antimicrobial activity against various pathogenic microorganisms, including methicillin-resistant Staphylococcus aureus (MRSA), was confirmed in the C₁₈ ODS open column fractions. Peak 2 compound was obtained using reversed-phase HPLC. As a result, this compound had a significant antimicrobial activity against various pathogenic microorganisms. In particular, it showed strong activity against MRSA, Mycobacterium smegmatis, Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus.

• Journal of the Economic Geographical Society of Korea
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• v.17 no.4
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• pp.801-816
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• 2014

This paper is a theoretically grounded empirical study aimed at shedding light on the Triple Helix of University-Industry-Government (U-I-G) relations in biotechnology cluster of Singapore. It questions the issue about the gap between theoretical consideration of the Triple Helix of U-I-G relations and the actual reality in biotechnology cluster, and the experience of Singapore was investigated. In terms of evolutionary perspective, biotechnology cluster in Singapore has gone through ongoing processes from a certain stage to other, and within the processes the Triple Helix nexus has been found. Analysis of the empirical study reveals significant findings: first, the government policies play a critical role in the operation of U-I-G relations rather than universities; second, therefore, the binding force of U-I-G relationships is based on the government policies being comprehensive including researchers immigration, student scholarship for local students, and tax and non-tax incentives for firms, rather than focusing on a targeted policy; third, the role of government starts from an initial stage, and it's role is ongoing processes by supporting infrastructure, human sources and continuous nourishment enabling the triple helix of U-I-G relations.

• Membrane Journal
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• v.31 no.2
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• pp.153-159
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• 2021

In recent years, polymer membranes, which are actively used in various industrial fields, have the advantage of being able to impart unique properties through the control of chemical structures and physical properties in the film-fabrication process, as well as through fabricating blend membranes mixed with various materials. In this study, the solubility parameter, which can be used as an index of miscibility with other materials, was calculated using molecular dynamics using a silkworm (Bombyx mori) silk polymer which has a wide potential to be used as an eco-friendly natural material. When the solubility parameter of polyvinylalcohol (PVA), which is also environmentally friendly and biocompatible, was calculated by molecular dynamics and compared with each other, it was confirmed that the two polymer materials had similar solubility parameter values. In conclusion, it was theoretically proved that the two polymers could blend well with each other, which was confirmed through experiments.

• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.52-60
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• 2022

Purpose: For now, cognitive load is assessed based on survey-based methods, which can be difficult to track the amount of cognitive load in real-time. In this study, we investigated the difference in electrophysiological activation due to different levels of cognitive load not only at sensor-level but also at source-level using electroencephalogram that might be potentially used for quantitative cognitive load evaluation. Materials and Methods: In this study, ten healthy subjects (mean age 24.3 ± 2.1, three female) participated the experiment. All participants performed 4 sessions of n-back task in different difficulties: 0-, 1-, 2-, and 3-back during electroencephalogram recording. For sensor-level analysis, we calculated the event-related potential and event-related spectral perturbation while low resolution brain electromagnetic tomography (LORETA) to estimate the source activation. Each result was compared between different workload conditions using statistical analysis. Results: Statistical results revealed that the accuracy of the task performance was significantly different between different cognitive loads (p = 0.018). The post-hoc analysis confirmed that the accuracy of the 3-back task was significantly decreased compared to 1-back condition (p = 0.018), but not with 2-back condition (p = 0.180). ERP results showed that P300 target amplitude between 1-back and 3-back had a marginal difference in Cz (p = 0.059) and Pz(p = 0.093). A significant inhibition in Cz high-beta activation (p = 0.017) and decrease in source activation of right parahippocampal gyrus was found in 3-back condition compared to 1-back condition (p < 0.05). Conclusion: In this study, we compared the sensor- and source-level differences in electroencephalogram between different levels of cognitive load, that were found to be in line with the previous reports related to cognitive load evaluation. We expect that the outcome of the current study can be used as a feature to establish a quantitative cognitive load assessment system.

• Science of Emotion and Sensibility
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• v.26 no.3
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• pp.149-160
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• 2023

This study develops a time-varying system-based noncontact fabric sensor that can measure cerebral blood-flow signals to explore the possibility of brain blood-signal detection and emotional evaluation. The textile sensor was implemented as a coil-type sensor by combining 30 silver threads of 40 deniers and then embroidering it with the computer machine. For the cerebral blood-flow measurement experiment, subjects were asked to attach a coil-type sensor to the carotid artery area, wear an electrocardiogram (ECG) electrode and a respiration (RSP) measurement belt. In addition, Doppler ultrasonography was performed using an ultrasonic diagnostic device to measure the speed of blood flow. The subject was asked to wear Meta Quest 2, measure the blood-flow change signal when viewing the manipulated image visual stimulus, and fill out an emotional-evaluation questionnaire. The measurement results show that the textile-sensor-measured signal also changes with a change in the blood-flow rate signal measured using the Doppler ultrasonography. These findings verify that the cerebral blood-flow signal can be measured using a coil-type textile sensor. In addition, the HRV extracted from ECG and PLL signals (textile sensor signals) are calculated and compared for emotional evaluation. The comparison results show that for the change in the ratio because of the activation of the sympathetic and parasympathetic nervous systems due to visual stimulation, the values calculated using the textile sensor and ECG signals tend to be similar. In conclusion, a the proposed time-varying system-based coil-type textile sensor can be used to study changes in the cerebral blood flow and monitor emotions.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.77.1-77.1
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• 2010

반도체 나노 결정은 크기와 모양에 따라 다른 광학적 전기적 성질을 보이는 독특한 특성 때문에 태양전지, 발광 다이오드, 레이저, 바이오메디컬 레이블링 등에 응용될 수 있는 저가격의 차세대 광전기 재료의 개발을 위한 구조체로 각광받고 있다. 최근에는 하나의 나노 결정에 type-II band offset을 가지는 두 개의 물질을 결합한 이종접합 나노 결정체의 연구가 활발하게 진행되고 있는데, 이는 나노 결정 내에서 빛에 의해 생성된 전하들을 공간적으로 분리해 낼 수 있는 장점을 가지고 있기 때문에 태양전지나 광촉매로의 응용에 매우 유용하다. 우리는 나노 결정과 고분자 하이브리드 태양전지의 제작에 있어서 성분과 type-II 이종접합 반도체 나노 결정의 영향을 조사하기 위하여 CdSe, CdTe, type-II CdTe/CdSe tetrapod을 합성하였다. CdSe tetrapod과 P3HT의 블렌딩에 의해 만들어진 태양전지는 AM 1.5, 100mW/$cm^2$ 조건에서 1.03%의 가장 높은 변환 효율, 그리고 415nm에서 43%의 IPCE를 나타내었다. 그리고 CdTe/CdSe type-II tetrapod 이종접합과 P3HT 블렌딩으로 만들어진 태양전지는 CdTe를 이용하여 만든 태양전지에 비해 4.4배의 변환효율과 3.9배의 단락전류를 나타내었다.

• Journal of the Korean Society of Food Culture
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• v.36 no.1
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• pp.103-109
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• 2021

The study was conducted to identify the anti-inflammatory and anti-cancer effects in sprouts of mouse-eyed bean (Rhynchosia nulubilis), ginseng (Panax ginseng), perilla (Perilla frutescens), broccoli (Brassica oleracea var. italica), and lettuce (Lactuca sativa) grown with organic germanium concentrate. Western blot analysis was performed to assess the anti-inflammatory activity of the extract. All extracts exhibited noticeable anti-oxidant activity, indicating a significant correlation between the germanium content and anti-oxidant activity (p<0.05). In particular, rat-eyed bean sprouts with the highest germanium content showed significant anti-inflammatory activity (p<0.05) by significantly inhibiting the expression of the inflammatory complexes, NLRP3, cytokines IL-1β and caspase-1. Ginseng and broccoli sprouts showed strong anti-cancer properties and had high anti-oxidant effects (p<0.001). Germanium-concentrated water allows the mass production of agricultural products containing high concentrations of organic germanium. Agricultural produce grown with germanium concentrate add organic germanium to various physiological active ingredients, increasing the anti-oxidant and anti-cancer effects. These results strongly suggest that agricultural products containing high germanium concentrations can be used as novel health supplements to improve health.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.spc
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• pp.54-60
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• 2023

The government focuses on promoting start-ups, fostering ventures, and creating an ecosystem of start-ups through the formation of a strong growth environment for small businesses. This study provides academic and practical implications about ways of improving our business incubator's support service across stages of growth through IPA. To this end, an Importance-Performance Analysis (IPA) was conducted to analyze relationship and differences in importance and satisfaction of business incubator's support service support at business incubation center. These results present to provide the following academic and practical implications. The academic implications are the need for differences in support services for each phase of start-up growth. As factors that could increase the likelihood of successful start-up were identified in each phase of the start-up growth, important information needed for policy and strategy was provided. As a practical suggestion, the managers and expert groups are presented with sections to be opened for each start-up growth stage, minimum effort input, and areas to be maintained continuously. A systematic support plan is established and a foundation is provided for improvement measures in efficient start-up business incubator's support service.

• Journal of Biomedical Engineering Research
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• v.45 no.1
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• pp.1-9
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• 2024

Communication with others plays an important role in human social interaction and information exchange in modern society. However, some individuals have difficulty in communicating due to dysarthria. Therefore, it is necessary to develop effective diagnostic techniques for early treatment of the dysarthria. In the present study, we propose a mobile device-based methodology that enables to automatically classify dysarthria type. The light-weight CNN model was trained by using the open audio dataset of Korean patients with dysarthria. The trained CNN model can successfully classify dysarthria into related subtype disease with 78.8%~96.6% accuracy. In addition, the user-friendly mobile application was also developed based on the trained CNN model. Users can easily record their voices according to the selected inspection type (e.g. word, sentence, paragraph, and semi-free speech) and evaluate the recorded voice data through their mobile device and the developed mobile application. This proposed technique would be helpful for personal management of dysarthria and decision making in clinic.