• 한국해양학회지
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• 제21권3호
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• pp.146-155
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• 1986

1984년 5월 50m수층과 1985년 10월 수온구조에 따른 여러 층에서 채집한 동 물플랑크톤 시료를 분석한 결과, 현존량은 춘계에 평균 538 inds/㎥, 추계에는 전 수층 평균과 표층이 각기 267inds/㎥와 508inds/㎥ 를 나타낸다. 양 계절에 동정된 분류군은 각기 55종류, 104종류였으며 연구해역의 서식 분류군은 123종류에 이른다. 동물플랑크톤 군집에서의 우점종의 순위는 양 계절 공히 copepods를 필두로 protozoans, appendicularians 이다. 표층에서의 아열대성 종과 현존량의 분포는 동 계에 있어 대마해류 및 북한한류수의 영향을 반영하는 것으로 사료되는 반면, 춘계 에는 현존량만이 식별할 수 있는 변화를 보인다. 1985년 추계에는 전 수층에 걸쳐 영구 수온약층의 저부인 120m 수심이 중층 냉수종의 분포에 대한 장벽으로서 중요 한 역할을 한다. 1985년 10월에 연속 채집한 시료의 분석결과, 식별할 수 있는 주야 수직이동은 나타나지 않는데, 이는 동물플랑크톤 가운데 진정한 심해종의 결핍으로 심층에서의 생체량이 아주 빈곤하고 따라서 동해에서의 수직이동이 미약하다는 이 론을 입증하는 것으로 사료된다.

• Journal of Korean Neurosurgical Society
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• 제63권4호
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• pp.415-426
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• 2020

Arteriovenous malformations (AVMs) are congenital anomalies of the cerebrovascular system. AVM harbors 2.2% annual hemorrhage risk in unruptured cases and 4.5% annual hemorrhage risk of previously ruptured cases. Stereotactic radiosurgery (SRS) have been shown excellent treatment outcomes for patients with small- to moderated sized AVM which can be achieved in 80-90% complete obliteration rate with a 2-3 years latency period. The most important factors are associated with obliteration after SRS is the radiation dose to the AVM. In our institutional clinical practice, now 22 Gy (50% isodose line) dose of radiation has been used for treatment of cerebral AVM in single-session radiosurgery. However, dose-volume relationship can be unfavorable for large AVMs when treated in a single-session radiosurgery, resulting high complication rates for effective dose. Thus, various strategies should be considered to treat large AVM. The role of pre-SRS embolization is permanent volume reduction of the nidus and treat high-risk lesion such as AVM-related aneurysm and high-flow arteriovenous shunt. Various staging technique of radiosurgery including volume-staged radiosurgery, hypofractionated radiotherapy and dose-staged radiosurgery are possible option for large AVM. The incidence of post-radiosurgery complication is varied, the incidence rate of radiological post-radiosurgical complication has been reported 30-40% and symptomatic complication rate was reported from 8.1% to 11.8%. In the future, novel therapy which incorporate endovascular treatment using liquid embolic material and new radiosurgical technique such as gene or cytokine-targeted radio-sensitization should be needed.

• Asian-Australasian Journal of Animal Sciences
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• 제30권12호
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• pp.1667-1673
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• 2017

Antibiotics have long been of great benefit for people, both in the medical treatment of human disease and in animal food where they improve the growth performance and feed utilization during animal production. Antibiotics as in-feed supplements affect all stages of pork production, including the gestation, nursing, growing, and finishing stages, although the effects show stage-dependent differences. However, the use of antibiotics in animal feed has become a worldwide concern. This review describes why sub-therapeutic levels of antibiotic additives in animal feed have become an integral part of animal feeding programs for more than 70 years, particularly in pork production. It also discusses the threat of the long-term use of sub-therapeutic levels of antibiotics in pork production. In recent years, the effectiveness of in-feed antibiotics has tended to decrease. This review analyzes this change from various perspectives. First, the equipment used at pig farms has improved dramatically and is more sanitary. Worldwide, more pig farms use pig farrowing crates, gestation crates, piglet nursery crates, flooring devices, piggery ventilation and cooler systems, automatic pig feeders, piggery heating equipment, and artificial insemination systems. In addition, scientists have replaced the use of antibiotics with organic acids, fermented mash, probiotics, prebiotics, minerals, oligosaccharides, enzymes, herbs/flavors, and protein/amino acids, and have improved management and husbandry techniques. In addition, animal welfare legislation has been aimed at improving the quality of the floors and living space, ensuring that animals have permanent access to fresh water, and setting a minimum weaning age. Finally, the prospects and the possibility of replacing antibiotics in pork production are described, in line with recent research results.

• 전력전자학회논문지
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• 제9권4호
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• pp.311-318
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• 2004

최근 각종 산업기기 및 자동화기기에는 회전자가 영구자석으로 구성된 브러시리스 전동기의 사용이 증가하고 있다. 그러나 회전자가 영구자석으로 이루어진 BLDC 전동기의 경우 회전자 위치 판별 센서는 필수 요소이다. 그러나 센서(엔코더, 레졸버등)를 사용할 경우 크기 증가, 비용 상승 등의 원인으로 작용한다. 따라서 본 논문에서는 PM BLDC 전동기의 속도제어를 수행함에 있어 기존의 엔코더와 Hall-IC 3개를 이용하지 않고, 두개를 이용하여 회전자의 위치를 판별함과 동시에 속도 센서를 대신하여 사용할 수 있는 방법을 제안하였다. 그 결과 성능은 동일하고, 구동회로의 크기와 제조 단가를 낮출 수 있는 효과를 얻었다.

• 전기전자학회논문지
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• 제24권3호
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• pp.867-876
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• 2020

본 논문에서는 3레벨 인버터로 구동되는 IPMSM의 고주파 주입 센서리스 운전에서 중성점 전압 리플 저감을 제안한다. 고주파 전압 주입 기반의 센서리스 제어는 IPMSM의 저속 영역에서 일반적으로 사용하는 센서리스 제어 기법이다. 고주파 전압 주입을 이용한 IPMSM의 센서리스 제어 과정에서 중성점에서의 전압 리플이 증가하는 문제가 발생한다. 중성점에서의 큰 전압 리플은 출력 전류를 왜곡시킬 뿐만 아니라 직류단 커패시터의 수명을 단축시키므로 저감되어야 한다. 본 논문에서 제안하는 기법은 지령 전압에 적절한 값을 보상하여 중성점 전압 리플을 저감하며, 보상값은 지령 전압과 전류를 이용하여 간단히 계산한다. 제안하는 중성점 전압 리플 저감 기법의 타당성은 시뮬레이션을 통해 검증한다.

• 한국산학기술학회논문지
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• 제9권2호
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• pp.317-326
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• 2008

본 논문은 MATLAB/SIMULINK와 dSPACE 1104 시스템을 사용하여 표면부착형 영구자석 동기전동기 벡터제어를 구현하였다. 영구자석 동기전동기는 고정자 전류를 자속발생 전류성분과 토크발생 전류성분으로 분리하고 이를 각각 독립적으로 제어함으로써 타여자 직류전동기처럼 다루는 것이 가능하기 때문에 기존의 직류전동기 제어에 사용되던 각종 제어 알고리즘을 적용하는 것이 가능하게 된다. 본 연구에서는 표면 부착형 영구자석 동기 전동기의 벡터제어를 구현하기 위하여, 먼저 MATLAB/SIMULINK 프로그램으로 영구자석 동기 전동기를 모델링하고 속도제어 부에는 비례-적분 제어기를, 전류제어 부에는 비간섭 비례-적분 제어기를 설계하여 제어기의 응답을 미리 확인하였다. 그리고 설계된 제어기의 성능을 입증하기 위하여 dSPACE DS1104 R&D Board에 시뮬레이션을 통해 구현된 영구자석 동기전동기 벡터 제어 프로그램을 다운로드하여 실험을 통해 제안된 벡터제어 시스템의 타당성을 입증하였다

• STI Policy Review
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• 제4권1호
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• pp.94-118
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• 2013

Innovation plays a large role in green growth. While it is a widely accepted view that, without innovation, it would be very difficult and costly to address major environmental issues, innovation itself tends to be constrained by limited access to eco-financing and is inherently risky, often requiring a long-term horizon. Although global consensus is more or less established as to the urgency and necessity of accelerating green innovation, the quality and quantity of financing in this area is largely insufficient, with increasing funding gaps in many countries. A new financial mechanism is urgently needed in order to re-orient financial flow and enable innovators to overcome the valleys of death that occur throughout the innovation cycle. A number of different modalities exist in financing the commercialisation of eco-innovation. Existing mechanisms have not been as successful as expected, revealing critical limits to furthering certain types of projects that are essential for economic and environmental progress. Experts' estimations have shown that the funding gap will widen in the coming years as demand for clean energy and green infrastructure rises, and as green technologies and innovation develop faster than the market for it can develop. Against this backdrop, the main purpose of this research is threefold: to identify issues and problems regarding current means of funding for eco-innovation and green projects; to provide insight into securing longterm green financing by looking at European cases; and ultimately to suggest policy implications for designing and implementing eco-specific financial instruments, focusing on governments' roles in sustainable financing for eco-innovation. This study analyses different models of financing mechanisms, a mix of public and private funds, in view of suggesting conditions for the sustainable financing of green projects, especially for large-scale high-risk projects. Based on the findings from the analyses of mechanisms and the shortcomings of the existing funding modalities, this study ultimately suggests policy implications for effectively supporting the commercialisation of eco-innovation.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.631-631
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• 2013

Battery has major drawbacks including its size and life expectancy, and environmental problem. As an alternative, energy harvesting is emerging as a potential solution to replace battery along with more energy-efficient IT devices. The idea of harnessing energy from our living environment is sustainable, semi-permanent, and eco-friendly. Also, unlike battery, energy harvester does not require much space to store energy. Therefore, energy harvesting can provide a better source of power for small, portable, and wireless devices. Among various ways of harvesting energy from our surroundings, triboelectricity is chosen due to its potential to be miniaturized, and efficient. Triboelectric effect occurs as two different materials with different polarity of charge separation come into contact through friction, and then become separated so that electric potential difference is achieved. In this research, such characteristic of triboelectricity is used as a way to convert ambient mechanical energy into electric energy.Series of recent researches have shown promising results that the triboelectric energy harvester can be simple and cost effective. However, sufficient electricity level required to operate mobile devices has not yet been achieved.In this research, our group focuses on the design and optimization of triboelectric energy harvesting device to enhance its output. By using maskless lithography to pattern Kapton film and silicon substrate, which is used as a mold for PDMS thin layer, and sputtering metal electrodes on each side, we fabricate and demonstrate different designs of triboelectric energy harvester that utilizes the contact electrification between a polymer thin film and a metal thin foil. In order to achieve optimized result, the output voltage and current are measured under diverse conditions, which include different surface structure and pattern, material, and the gap between layers.

• 융합정보논문지
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• 제10권2호
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• pp.201-210
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• 2020

본 연구는 미용 목적의 문신시술에 대한 기존의 법률적 한계점을 파악하고 미용인의 시술행위에 대한 법률적 합법화 및 전문 자격사 제도의 필요성을 제기하기 위한 목적을 지니고 있다. 미용 및 법률분야의 전문가 10명과 피시술자 101명을 대상으로 각각 심층인터뷰와 설문조사를 실시한 결과는 다음과 같다. 첫째, 10명의 전문가는 다수의 시술이 불법으로 이루어지는 점을 고려하여 법규가 현실을 반영하지 못한다고 지적하였으며, 전문 자격사제도의 도입에 대한 필요성과 찬성의 의견을 제시하였다. 둘째, 피시술자 중 15.7%만이 의사에게 시술받았다고 응답하였으며, 시술품질, 만족도, 추천의도는 비의료인이 더욱 높게 나타났다. 한편, 시술 부작용은 의료인과 비의료인이 차이가 없으며, 응답자의 73.7%가 전문 자격사 제도가 필요하다고 응답하였다. 본 연구는 미용 목적의 문신 시술에 대한 사회적 인식을 반영한 정부정책의 개선이 필요하다는 점을 실증적으로 지지한다.

• 대한치과교정학회지
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• 제46권5호
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• pp.331-342
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• 2016

Objective: To evaluate the accuracy and reliability of the diagnostic tools available for assessing maxillary transverse deficiencies. Methods: An electronic search of three databases was performed from their date of establishment to April 2015, with manual searching of reference lists of relevant articles. Articles were considered for inclusion if they reported the accuracy or reliability of a diagnostic method or evaluation technique for maxillary transverse dimensions in mixed or permanent dentitions. Risk of bias was assessed in the included articles, using the Quality Assessment of Diagnostic Accuracy Studies tool-2. Results: Nine articles were selected. The studies were heterogeneous, with moderate to low methodological quality, and all had a high risk of bias. Four suggested that the use of arch width prediction indices with dental cast measurements is unreliable for use in diagnosis. Frontal cephalograms derived from cone-beam computed tomography (CBCT) images were reportedly more reliable for assessing intermaxillary transverse discrepancies than posteroanterior cephalograms. Two studies proposed new three-dimensional transverse analyses with CBCT images that were reportedly reliable, but have not been validated for clinical sensitivity or specificity. No studies reported sensitivity, specificity, positive or negative predictive values or likelihood ratios, or ROC curves of the methods for the diagnosis of transverse deficiencies. Conclusions: Current evidence does not enable solid conclusions to be drawn, owing to a lack of reliable high quality diagnostic studies evaluating maxillary transverse deficiencies. CBCT images are reportedly more reliable for diagnosis, but further validation is required to confirm CBCT's accuracy and diagnostic superiority.