• Journal of Biomedical Engineering Research
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• v.43 no.4
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• pp.193-198
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• 2022

Contrast enhanced magnetic resonance imaging using gadolinium-based contrast agent (GBCA) is a very useful in vivo technique to visualize the inner ear pathology including endolymphatic hydrops. Although systemic intravenous (IV) administration can visualize the perilymph space, the visualization was possible by indirect passage of contrast agent through blood-perilymph barrier. All animal experimental procedures were performed under anesthesia with 5% isoflurane. Lipopolysaccharide (LPS) was instilled into the left tympanic cavity through the tympanic membrane using a sterile 27gauge needle to induce hydrops model. Tucker-Davis Technologies system was used to measure Auditory Brainstem Responses (ABRs). For intracerebroven-tricular (ICV) administration, 25 µmol of GADOVIST (Bayer, Berlin, Germany) was used and diluted GADOVIST injection was 10 µl. MR imaging was acquired with a 9.4 Tesla MRI scanner. Transmit-receive volume coil with 40 mm inner diameter and 75 mm out diameter was used. ICV administration well demonstrated the strong enhancement along the cerebrospinal fluid (CSF) microcirculation pathway including CSF fluid in the subarachnoid space and CSF space of the inner ear structures. On the other hand, IV administration showed no contrast enhancement along the CSF microcirculation pathway and showed weak enhancement in the inner ear structures. In case of rat hydrops model, ICV administration showed that the reduced contrast enhancement in the perilymph space of the hydrops induced inner ear compared to the contrast enhancement in the perilymph space of the normal inner ear. New systemic ICV administration method provide contrast enhancement of GBCA in the inner ear through CSF microcirculation pathway.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1409-1410
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• 2015

현대기술의 발달로 인해 인간의 삶 중 많은 부분을 기계가 차지하고 있다. 특히 로봇공학 분야는 위험하거나 혹은 매우 정밀함을 요하는 일, 단순반복 등 인간이 기피하거나 하기 어려운 일을 대신 해줌으로서 많은 관심을 받고 있다. 이에 우리는 우리 생활에 가장 깊숙히 들어와 있는 로봇팔분야에 대해 말하고자 한다. 현재 로봇팔은 산업용은 물론, 의료용, 재해용 등 다양한 분야에서 사용되고 있다. 하지만 매우 정밀하고 정확한 작업을 위해 만들어져 있음에도 불구하고, 약간의 충격에도 이상이 생긴다거나, 기기의 이음세 부분의 잦은 회전으로 마모가 발생하게 되고 그에 따라 미세한 오차가 발생한다. 그런 상황을 방지하고자, 우리는 PSD(Position Sensitive Detecter)센서를 이용해 실시간으로 굽힘각을 측정 및 감시하여 보다 정확한 구동을 유도하려 한다. 이는 단순한 로봇팔만이 아닌 휴머노이드나 다른 회전을 이용하는 기기라면 어디든 쉽게 적용 할 수 있을 것이다.

• Convergence Security Journal
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• v.17 no.2
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• pp.159-164
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• 2017

The international community recognizes North Korea's nuclear and missile provocation as a real threat. This is due to the analysis and evaluation that has developed nuclear electro magnetic pulse of domestic and overseas North Korea experts, intelligence agencies related to electro magnetic pulse. Electro magnetic pulse experts are concerned about North Korea's nuclear electro magnetic pulse in the following aspects. First, industrial, military, medical, and living facilities in modern society are constructed with electrical and electronic systems. So, All electrical and electronic appliances will become neutralization if North Korea's nuclear electro magnetic pulse was set off over the world(i.e. Korean Peninsula, United States etc). Second, North Korea will judge that possibility of criticism by the international community is low from the point of view of an attacker. Because nuclear electro magnetic pulse aim to destroy only the electronic equipment of the opposite nation and cause damage rather than taking life. Finally, nuclear electro magnetic pulse is more threatening than weapons like mass destruction because it does not need to hit targets accurately and can strike a wide area with nuclear weapon of the low technology levels. In this respect, we will analyze and evaluate nuclear and missile development and make a prospects about nuclear electro magnetic pulse developed by North Korea.

• Journal of Korean Foot and Ankle Society
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• v.26 no.2
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• pp.84-87
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• 2022

Purpose: This was a pilot study to examine the clinical usefulness of the newly developed three-dimensional sweep mode extracorporeal shockwave treatment (ESWT) in patients with plantar fasciitis. Materials and Methods: Three-dimensional sweep mode ESWT was performed once a week for 5 weeks in patients with plantar fasciitis who showed no improvement with the conventional conservative treatment. A 100-mm visual analogue scale (VAS) reading for pain from walking and at rest after walking were collected before the treatment and 8 and 16 weeks after the initial treatment. In addition, the Foot and Ankle Outcome Score (FAOS) and EuroQol-5-dimension (EQ-5D) scores before and 16 weeks after the treatment were evaluated. Results: VAS for pain for walking improved from 50.60±8.38 to 19.80±15.61 at 8 weeks after the initial treatment (p=0.008) and 9.80±9.62 at 16 weeks after the treatment (p<0.001). VAS for pain at rest after walking improved from 36.60±19.55 to 11.80±12.95 at 8 weeks after the initial treatment (p=0.052) and 8.80±8.87 at 16 weeks after the treatment (p=0.024). Preoperative FAOS increased from an average of 74.80±9.73 before the treatment to an average of 81.00±8.86 at week 16 after the procedure (p=0.49) and compared to pre-treatment levels, there was a decrease of one level in the anxiety/depression domain of the EQ-5D, post-treatment. Conclusion: The results of this preliminary study confirmed that the newly developed EWST with the smart forging sweep mode was effective in improving pain and function in plantar fasciitis.

• Journal of Korea Port Economic Association
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• v.36 no.4
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• pp.107-120
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• 2020

This study analyzed the competitiveness of major export industries following the FTA between Korea and five Central American countries. Findings revealed that Korea mainly exports industrial products such as ships, automobiles and parts, steel, and electronic devices, and it imports raw materials and agricultural products such as coffee and copper, indicating a complementary trade structure. Similarly, the trade specialization index analysis revealed that Korea specialized in exporting industrial products such as ships, automobiles, steel, and machinery, and in importing primary products such as copper and coffee. Products such as ships, steel, and machinery, which are major export items to Central America, are expected to further strengthen their competitiveness due to tariff cuts. In addition, it is expected that the demand for medicines and medical supplies could increase in future due to the COVID-19 pandemic. This study attempted to present implications for establishing export strategies by analyzing the competitiveness of Korea's major export industries in the Central American market, in accordance with the Korean-Central American FTA. These findings could be used as basic data for future entry into South America as a bridgehead in the Central American market.

• Journal of Korea Technology Innovation Society
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• v.15 no.2
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• pp.443-460
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• 2012

Technology is closely related to industrial development and various studies have been performed to understand the linked structure for knowledge flow between the technology and industry. The research, however, wasn't carried out to flow for Korea National Research and Development projects. In this study, linked structure for technology-industry was discussed by utilizing patent data performed in actual National R&D using NTIS Information of the national research and development, and then it was analyzed how knowledge flows between the technology and industry are flowing. It should be defined that the individual applications expected by researchers at the start of the research and technology-industry applications actually applied from the research performances after research was completed. As a result, it was confirmed in most projects the flow of knowledge was occurring to predicted industries before the start of the R&D. However, the technology was applied to unexpected industry in three industries such as Y09(medical, precision and optical instruments), Y10(electrical and mechanical equipment), Y11(automotive and transportation equipment). The results of this study will be able to contribute to planning for efficient investment strategy of technology-industry by investigating the technology-industry knowledge flow relations of national R&D projects.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.139-139
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• 2003

많은 압전 후막은 여러 감지소자, 통신 및 사무자동화 기기, 전기 및 전자부품, 의료장비 및 국방산업에 까지 널리 응용되어 왔다. 그 중에서도 압전특성이 뛰어난 PZT 후막은 마이크로 펌프, 밸브, 헤드, 모터, 트랜스듀서 뿐 아니라 최근 바이오칩용 센서와 액추에이터로서 널리 연구되고 있다. 또한 마이크로 센서와 액추에이터 의 제작 및 구동을 위한 MEMS 기술의 도입으로 실리콘 베이스의 소자 개발이 집중되고 있다. 스크린 프린팅 방법은수 마이크론에서 수십 마이크론 후막의 실현이 용이하고 비교적 경제적이며 소자신뢰도가 높고 대량생산에 유리하여 활발한 연구가 진행 중이다. 그러나 후막은 벌크에 비해 기공률이 높고, 또 소자응용에 있어서 고온소결 시 MEMS공정을 위한 실리콘 베이스 기판과의 확산 및 반응에 의 한 계면 및 활물질 성능의 저하가 문제가 되고 있다. 따라서 본 연구에서는 스크린 프린팅과 더불어 졸 코팅 방법의 도입으로 후막의 성형 및 소결 밀도를 높임과 동시에 여러 확산 방지 막의 증착으로 capacitor 형 PZT 후막의 물성 및 전기 적 특성을 향상시키고자 하였다.

• The Journal of Korean Institute of Information Technology
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• v.17 no.1
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• pp.149-156
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• 2019

Mixed reality technology (MR) has become one of the fourth industrial revolution element technologies. MR technology has been widely applied not only as a digital contents industry but also in the fields of architecture, tourism, medical field, and education. In this paper, we propose a collaborative service platform for architectural applications that inter-operate with heterogeneous devices such as MR device, PC and mobile, and develop prototype system and verify it. As a result, the 3D model using the skp extension, which is mainly used in architecture design office, was created by using developed prototype system and generate the MR contents for the hololens, which is the MR device, and the conversion time and normal operation were confirmed.

• Journal of Biomedical Engineering Research
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• v.43 no.2
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• pp.109-115
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• 2022

Purpose: Medical records classification using vectorization techniques plays an important role in natural language processing. The purpose of this study was to investigate proper vectorization techniques for electronic medical records classification. Material and methods: 403 electronic medical documents were extracted retrospectively and classified using the cosine similarity calculated by Scikit-learn (Python module for machine learning) in Jupyter Notebook. Vectors for medical documents were produced by three different vectorization techniques (TF-IDF, latent sematic analysis and Word2Vec) and the classification precisions for three vectorization techniques were evaluated. The Kruskal-Wallis test was used to determine if there was a significant difference among three vectorization techniques. Results: 403 medical documents were relevant to 41 different diseases and the average number of documents per diagnosis was 9.83 (standard deviation=3.46). The classification precisions for three vectorization techniques were 0.78 (TF-IDF), 0.87 (LSA) and 0.79 (Word2Vec). There was a statistically significant difference among three vectorization techniques. Conclusions: The results suggest that removing irrelevant information (LSA) is more efficient vectorization technique than modifying weights of vectorization models (TF-IDF, Word2Vec) for medical documents classification.

• Journal of Biomedical Engineering Research
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• v.44 no.1
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• pp.19-24
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• 2023

Due to the spread of COVID-19, many patients with severe respiratory diseases have occurred worldwide, and accordingly, the use of mechanical ventilators has exploded. However, hospitals do not have systematic risk management, and the Medical Device Regulation also provides medical device risk management standards for manufacturers, but does not apply to devices in use. In this paper, we applied the Failure Mode Effects Analysis (FMEA) risk analysis technique based on the International Standard ISO 14971 (Medical Devices-Application of risk management to medical devices) for 85 mechanical ventilators of a specific model in use in hospitals. Failure modes and effects of each parts were investigated, and risk priority was derived through multiplication of each score by preparing criteria for severity, occurrence, and detection for each failure mode. As a result, it was confirmed that the microprocessor-based Patient Unit/Monitoring board in charge of monitoring scored the highest score with 36 points, and that reliability management is possible through systematic risk management according to priority.