잡음 학생 모델 기반의 자가 학습을 활용한 음향 사건 검지

김남균,박창수,김홍국,허진욱,임정은,Kim, Nam Kyun,Park, Chang-Soo,Kim, Hong Kook,Hur, Jin Ook,Lim, Jeong Eun 한국음향학회 2021 韓國音響學會誌 Vol.40 No.5

In this paper, we propose an Sound Event Detection (SED) model using self-training based on a noisy student model. The proposed SED model consists of two stages. In the first stage, a mean-teacher model based on an Residual Convolutional Recurrent Neural Network (RCRNN) is constructed to provide target labels regarding weakly labeled or unlabeled data. In the second stage, a self-training-based noisy student model is constructed by applying different noise types. That is, feature noises, such as time-frequency shift, mixup, SpecAugment, and dropout-based model noise are used here. In addition, a semi-supervised loss function is applied to train the noisy student model, which acts as label noise injection. The performance of the proposed SED model is evaluated on the validation set of the Detection and Classification of Acoustic Scenes and Events (DCASE) 2020 Challenge Task 4. The experiments show that the single model and ensemble model of the proposed SED based on the noisy student model improve F1-score by 4.6 % and 3.4 % compared to the top-ranked model in DCASE 2020 challenge Task 4, respectively.

Clinical Results of High-Dose Chemotherapy Followed by Autologous Peripheral Blood Stem Cell Transplantation in Children with Advanced Stage Rhabdomyosarcoma

김남균,Hyo Sun Kim,서창옥,김현옥,유철주 대한의학회 2012 Journal of Korean medical science Vol.27 No.9

Regardless of improvement in cure of Rhabdomyosarcoma (RMS), the results in treatment of advanced stage of RMS in children are still dismal. Recently, high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (HDC/APBSCT) has been tried to manage the advanced high-risk RMS patients. We investigated the effectiveness of HDC/APBSCT by reviewing the clinical records of high-risk pediatric RMS patients in single institute database. Over twenty years, 37 patients were diagnosed as RMS with high-risk at the time of first diagnosis. These patients were classified as two groups according to treatment method. The first group was HDC/APBSCT and the other was conventional multi-agent chemotherapy group. Differences of clinical results between the two groups were analyzed. The median age of patients was 5 yr, ranging from 6 months to 15 yr. The 5-yr event free survival rate (EFS) of all patients was 24.8% ± 4.8%. HDC/APBSCT group and conventional multi-agent chemotherapy group were 41.3% ± 17.8% and 16.7% ± 7.6% for 5-yr EFS, respectively (P = 0.023). There was a significant difference in the result of HDC/APBSCT between complete remission or very good partial response group and poor response group (50% ± 20.4% vs 37.5% ± 28.6%, P = 0.018). HDC/APBSCT can be a promising treatment modality in high-risk RMS patients.

초고층 프로젝트 양중 계획의 실패 유형별 핵심 리스크 요인 분석

김남균,김예상,Kim, Nam-Gyun,Kim, Yea-Sang 한국건설관리학회 2013 한국건설관리학회 논문집 Vol.14 No.4

최근 국내 외 대도시를 중심으로, 글로벌 경제 위기와 부동산 경기 침체로 중단되거나 연기되었던 초고층 프로젝트들이 재개되고 있으며, 이를 수주하기 위한 건설사들의 경쟁은 전보다 더욱 치열해지고 있다. 국내 건설사들이 초고층 건축 분야에서 경쟁력을 높이기 위해서는, 전체 프로젝트의 근간이 되는 중요한 요소인 양중계획의 체계적인 리스크 관리가 반드시 수반되어야 하지만, 여전히 개인적 경험에 의존하여 작성 된, 양중계획의 오류로 인한, 현장 전체의 공기 지연 및 원가 관리 실패의 문제가 빈번하게 발생하고 있다. 따라서 본 연구에서는, 양중계획의 정확성을 높이기 위한 방안으로, 현행 양중계획 체계의 문제점을 분석하고, 계획 요소에 따라 실패 유형을 도출하였으며, 각 실패 유형이 전체 프로젝트의 공정, 원가, 안전관리에 미치는 영향도를 분석하였다. 또한 양중 장비별 세부 리스크 요인을 분석하고, 이를 바탕으로 FMEA 기법을 적용하여 초고층 프로젝트 양중계획의 핵심 리스크 요인을 도출하였다. Recently, not only around Korea but also other countries shows a pattern of arising high-rise building construction project which was delayed or aborted during global economic crises and recession. Although the market starts to stretch, It is getting competitive to win a contract in high-rise construction project between contractors due to lack of competitive advantage especially to Korea contractors. To get that, Korean contractors needs lifting equipment plan. But currently, they depend on the empirical methods and that cause schedule delay, not controlled cost management problem. Therefore, this research is to improve the accuracy of Lifting plan by analyzing the current issues of Lifting plan system and deducing the types of failures with planning factors, as well as analyzing the impact on schedule and cost control and safety management by each failure mode. Also, by analyzing detail risk factors per Lifting Equipment with FMEA, to infer the critical risk factor on high-rise construction project.

국내 가전기기의 대기전력 현황과 전망

김남균,Kim, Nam-Gyun 전력전자학회 2006 전력전자학회지 Vol.11 No.4

국가 건설교통 R&D 사업의 실용화 향상을 위한 기술성숙도평가 기반 R&D 평가모델 수립에 관한 연구

김남균,안병호,이현석,최재홍,박상혁,김예상,Kim, Nam-Gyun,An, Byung-Ho,Lee, Hyun-Seok,Choi, Jae-Hong,Park, Sang-Hyuk,Kim, Yea-Sang 한국건설관리학회 2012 한국건설관리학회 논문집 Vol.13 No.4

최근 지식기반 경쟁시대가 도래함에 따라, 우리나라를 포함한 주요 선진국은 R&D 투자를 확대하고, R&D사업의 성과확산 정책을 추진하고 있다. 이를 위해 미국의 NASA, DoD 등의 기관은 정량화된 성관관리 지표로서, 기술성숙도(TRL)를 정의하고, 이를 기준으로 판단하는 기술성숙도 평가체계(TRA)를 도입하여 활용하고 있으며, 이러한 도구는 특히 실용화를 목적으로 하는 R&D사업에 매우 효과적인 것으로 평가되고 있다. 이와 같은 개념은 실용화를 목적으로 하는 국내 국가 건설교통 R&D사업에 적용했을 때, 현재 연구내용의 학술적 성과에 치중되어있는 평가체계의 단점을 극복하고 실용화 달성의 취지를 크게 개선할 수 있을 것으로 기대되며, 따라서 본 연구에서는 TRL 및 TRA 개념과 국내 국가 건설교통 R&D사업의 특성 및 현행 평가 관리체계를 분석하여 실용화 목적 달성을 위한 건설교통 R&D 사업의 TRL TRA 수행 모델을 제시하였다. Recently as the advent of knowledge-based competition, the major industrialized countries including Korea, are expanding their R&D investment and promoting policies for diffusing of R&D performance. For this, NASA, DoD and such agencies in the United States define Technology Readiness Level (TRL) as a quantified indicator for performance management, and also impose Technology Readiness Assessment (TRA) as a evaluation system, that evaluates technology maturity using TRL. These tools are judged to be very effective in R&D projects especially with the object of practical use. When this concept is applied to the domestic national construction and transportation R&D project for the purpose of practical use, it is expected that the evaluation system overcomes its weakness of focusing only on academic results and improves significantly on intent of achieving practical use. Thus in this study, TRL/TRA implementation model of construction and transportation R&D project for achieving purpose of practical use is presented through an analysis of TRL/TRA concept and domestic national construction and transportation R&D project's characteristics and current evaluation/management system.

구강저에 발생한 유피낭종 1예

김남균,김동현,박용수,전은주,Kim, Nam-Gyun,Kim, Dong-Hyun,Park, Yong-Soo,Jeon, Eun-Ju 대한기관식도과학회 2010 大韓氣管食道科學會誌 Vol.16 No.1

Epidermal cyst in the floor of mouth is relatively rare disease. Patients usually present soft and non-tender mass at the midline of mouth floor. Careful history taking and imaging study are needed for the diagnosis and surgical excision is the choice of treatment. We report a case of huge epidermal cyst located in the floor of mouth mimicking plunging ranula, which was successfully removed by transoral surgical excision without any complication. It was diagnosed as an epidermal cyst by pathologic examination.

졸음운전의 자동 검출 및 각성 시스템 개발에 관한 연구

김남균,정경호,김법중,Kim, Nam-Gyun,Jeong, Gyeong-Ho,Kim, Beop-Jung 대한의용생체공학회 1997 의공학회지 Vol.18 No.3

Driving is a complex vigilance task that includes improper lookout, excessive speed and inattention. The primary objective of this research is to detect driver drowsiness so that the driver can be alerted to an impending traffic accident in performance. We developed the automatic detection and warning system during drowsy driving. A drowsiness detection system must be able to monitor driver status and detect the detrimental changes of a driver performance. Eyeblink has been found to be a reliable factor of drowsiness detection in earlier studies. As an additional parameter, we also considered the yawning which often occurs in a low vigilance state and predicts the drowsy state. We used a computer vision method to extract the eyeblink and yawning in the face image sequences. When the drowsy state was detected, the driver was refreshed by alarming device and menthol scent generator after deciding the warning level by fuzzy logic. For the evaluation of our system, we measured the physiological parameters such as EOG and EEG. The results indicated that it is possible to detect and alert the driver drowsiness temporarily or continuously by using our system.

빛과 소리 자극에 대한 지각 운동의 협력에 관한 연구

김남균,고영호,Kim, Nam-Gyun,Ko, Yong-Ho,Ifukube, T. 대한의용생체공학회 1994 의공학회지 Vol.15 No.1

We investigated the characteristic of the sensory motor coordination by measuring the hand point ins and the gaze movement to the visual and sound stimulation. Our results showed that the gaze vol ocity to sound stimulation did not depend on stimulation direction, but lagged behind 0.2 sec toward the pheriperal direction to the visual stimulation. Our data showed that to both visual and sound stimulation, the error of hand pointing value increased with an increasement of eccentricity.

벗김강도 측정법에 의한 파워 모듈의 솔더접합 특성 평가

김남균,이희흥,방욱,서길수,김은동,Kim, Nam-Kyun,Lee, Hee-Heung,Bahng, Wook,Seo, Kil-Soo,Kim, Eun-Dong 한국전기전자재료학회 2003 전기전자재료학회논문지 Vol.16 No.12

The strength and characteristics of the soldering interface of the power semiconductor chip in a power module has been firstly surveyed by the peel strength measurement method. A power module is combined with several power chips which generally has 30∼400$\textrm{mm}^2$ chip area to allow several tens or bigger amps in current rating, so that the traditional methods for interface characterization like shear test could not be applied to high power module. In this study power diode modules were fabricated by using lead-tin solder with 10${\times}$10$\textrm{mm}^2$ or 7${\times}$7$\textrm{mm}^2$ soldering interface. The peel strengths of soldered interfaces were measured and then the microscopic investigation on the fractured surfaces were followed. The peel test indicated that the crack propagated either through the bulk of the soft lead-tin solder which has 55-60 kgf/cm peel strength or along the interface between the solder and the plated nickel layer which has much lower 22 kgf/cm strength. This study showed that the peel test would be a useful method to quantify the solderability as well as to recognize which is the worst interface or the softest material in a power module with a large soldering area.

SiC 고전압 소자 기술

김남균,방욱,김은동,이종홍,정종원,Kim, Nam-Kyun,Bang, Wook,Kim, Eun-Dong,Lee, Jong-Hong,Jung, Jong-Won 한국전기전자재료학회 2002 전기전자재료 Vol.15 No.6