IMU Self-Calibration Using Factorization

Myung Hwangbo,Jun-Sik Kim,Kanade, T. IEEE 2013 IEEE transactions on robotics Vol.29 No.2

<P>This paper presents a convenient self-calibration method for an inertial measurement unit (IMU) using matrix factorization. Using limited information about applied loads (accelerations or angular rates) available from natural references, the proposed method can linearly solve all the parameters of an IMU in any configuration of its inertial components. Our factorization-based calibration method exploits the bilinear form of an IMU measurement, which is the product of intrinsic calibration parameters and exerted loads. For a redundant IMU, we prove that partial knowledge of the loads, such as magnitude, can produce a linear solution space for a proper decomposition of the measurement. Theoretical analysis on this linear space reveals that a 1-D null space should be considered when load magnitudes are all equal (e.g., gravity loads). Degenerate load distributions are also geometrically identified to avoid singular measurement collection. Since a triad IMU has a lower number of sensor components than a 4-D parameter space, we propose an iterative factorization in which only initial bias is required. A wide convergence region of the bias can provide an automatic setting of the initial bias as the mean of the measurements. Performance of the proposed method is evaluated with respect to various noise levels and constraint types. Self-calibration capability is demonstrated using natural references, which are gravity for accelerometers and image stream from an attached camera for gyroscopes. Calibration results are globally optimal and identical to those of nonlinear optimization.</P>

원전 입지와 온배수로 인한 사회 갈등과 공동체 변화

황보명(Hwangbo, Myung),윤순진(Yun, Sun-Jin) 한국공간환경학회 2013 공간과 사회 Vol.24 No.1

이 연구는 원자력발전소의 입지와 원전에서 배출하는 온배수가 방사능 위험 못지않게 지역사회에 다양한 변화를 일으키며 환경 갈등을 발생시켜왔다는 사실에 주목한다. 이에 따라 온배수로 인한 피해를 직접적으로 경험한 한빛원전 주변지역인 전라남도 영광군 홍농읍 계마리를 연구 대상지로 선정하여 현장답사와 함께 이해관계를 가진 당사자들을 대상으로 심층면접을 실시하고 갈등 분석법을 적용하여 분석함으로써 갈등 요인과 갈등의 전개 과정, 지역사회 변화 양상을 파악했다. 그 결과 한빛원전 온배수 관련 갈등은 갈등맹아기 ― 갈등표출기 ― 갈등확대기 ― 갈등심화기를 지나 갈등교착기로 접어들었으며, 온배수의 피해 범위, 온배수 저감 방안으로 설치한 방류제의 저감 효과, 온배수 피해보상 범위와 방식 등 3가지 쟁점을 둘러싸고 지역사회 내 갈등이 더욱 심화되고 있음을 발견했다. 또한 이러한 쟁점을 둘러싼 갈등의 구조화로 인해 계마리 어민과 한빛원전 사이의 갈등을 넘어 계마리 비어민과 어민, 계마리 어민 공동체 내부, 계마리 이외 주민과 계마리 지역 주민 사이에 새로운 갈등이 야기되고 지역 공동체가 분열되는 양상을 보이고 있음을 확인했다. 이러한 연구결과는 원전입지가 야기하는 문제점을 보다 폭넓게 파악함으로써 원전 입지의 사회적 영향의 범위를 총체적으로 조명하는 것이 필요하며 그 결과 원전정책은 더욱더 신중하게 추진되어야 함을 시사한다. This study aims to explore how social conflicts resulting from thermal effluents of nuclear power plants have been shaped and how they have changed the community, while paying attention to the fact that thermal effluents, not just radioactive risk, have caused environmental conflicts and various social changes. To do this, this study selected Gyema-ri Hongnong-eup Younggwang-gun as a study site and conducted field research and in-depth interviews with diverse stake-holders. This study then carried out a conflict analysis to analyze causes and development processes of conflicts and to grasp changes in the community. As a result, this study found that conflict from thermal effluents of the research site has been deepened through conflict stages of embryo, expression, extension, escalation and deadlock. In addition, it identified three major conflicting issues including the scope of damage resulting from thermal effluents, the reduction effect of the discharge article, and the scope of compensation scope and way. It also found that the Gyema-ri community around the Hanvit nuclear power plant has experienced conflicts among local residents and has consequently been split. The conflicts have been shaped between fishermen and non-fishermen, residents of Gyema-ri and others, and among fishermen, beyond the original confrontation between fishermen of the Gyema-ri and the Hanvit nuclear power plant. This study result implies that it is necessary to grasp broader social impacts of nuclear power plants and to take nuclear policies more cautiously based on holistic understanding of problems caused by nuclear power.

Incidence of Diabetes After Cancer Development : A Korean National Cohort Study

Hwangbo, Yul,Kang, Danbee,Kang, Minwoong,Kim, Saemina,Lee, Eun Kyung,Kim, Young Ae,Chang, Yoon Jung,Choi, Kui Son,Jung, So-Youn,Woo, Sang Myung,Ahn, Jin Seok,Sim, Sung Hoon,Hong, Yun Soo,Pastor-Barriu American Medical Association 2018 JAMA oncology Vol.4 No.8

<P>CONCLUSIONS AND RELEVANCE In this large Korean cohort, cancer development increased the risk of subsequent diabetes. These data provide evidence that cancer is associated with an increased risk of diabetes in cancer survivors independent of traditional diabetes risk factors. Physicians should remember that patients with cancer develop other clinical problems, such as diabetes, with higher frequency than individuals without cancer, and should consider routine diabetes screening in these patients.</P>

Alterations in Seed Vigour and Viability of Soybean Related with Accelerated Seed Aging and Low Dose Gamma Irradiation

Hwangbo, Jun-Kwon,Kim, Jae-Sung,Lim, Ji-Hyeok,Baek, Myung-Hwa,Chung, Byung-Yeoup The Korean Society of Crop Science 2003 Korean journal of crop science Vol.48 No.4

The objective of this study was to demonstrate whether or not the deleterious effects of accelerated aging on seed vigour and viability are alleviated by interaction with gamma irradiation. Seeds of soybean (Glycine max L.) were artificially aged and subsequently irradiated with 4 and 8 Gy of gamma irradiation. Germination rate was negatively affected by accelerated aging and positively by gamma irradiation, with a positive interaction of a 3day-seed aging treatment occurring with 4 Gy, possibly suggesting that 4 Gy of gamma irradiation partially offset the adverse effects of seed aging on germination. However, 5-day aged seeds did not gain any benefits from the gamma irradiation. Electrolyte leakage from the seeds increased with the duration in days aged. Irradiation, however, did not impose any effects on the leakage. Respiration rate of the seed with hypocotyl and primary root was significantly low for the aged seeds, but not for the seeds with both irradiation and aging treatments. Accelerated aging decreased the dry weight of the hypocotyl and primary root of the seeds without any measurable effects of irradiation. $\alpha$-Amylase activity decreased with seed aging and positively responded to gamma irradiation. The data is discussed with regard to the possible roles of gamma irradiation for improving the seed vigour and viability of aged seeds.

Early Germination Response of Soybean Seed to Accelerated Aging and Low Dose Gamma Irradiation

Hwangbo, Jun-Kwon,Kim, Jae-Sung,Lim, Ji-Hyeok,Baek, Myung-Hwa,Chung, Byung-Yeoup,Kim, Jin-Hong The Korean Society of Crop Science 2004 Korean journal of crop science Vol.49 No.1

The responses of soybean seeds were evaluated to accelerated aging and gamma irradiation with regard to germination, seed leakage, seed leachate component and dry weight of hypocotyl and primary root of the germinating seed. Accelerated aging significantly reduced the final germination rate while gamma irradiation increased the final germination rate. Furthermore, the interactive effects occurred that the final germination rate of 5-day aged seeds increased considerably in response to 4 Gy of gamma irradiation. The extent to which the electrolyte was leaked from the seeds (conductivity) was significantly affected by accelerated aging and showed a close negative correlation with the germination rate. Gamma irradiation, however, did not significantly affect the electrical conductivity of seed leachate. The accelerated aging significantly increased the concentrations of the particular electrolytes leaked from the seeds while the gamma irradiation did not affect those concentrations. Of the electrolytes leaked from the seeds, Ca and Mg showed relatively lower concentrations while K showed greater concentrations than others. Moreover, N and P showed similar responses to aging treatment. Aging treatment significantly affected dry weight (DW) of hypocotyls and primary root. Also, gamma irradiation decreased DW of hypocotyls and primary root, particularly for 8 Gy associated with 5 days aging treatment. The data were discussed in terms of the relationships of seed vigor with aging treatment and gamma irradiation.

The Effects of Neuromuscular Electrical Stimulation on Swallowing Function in Acute Stroke Patients with Dysphagia

Kim, Myung-Kwon,Lee, Chang-Ryeol,HwangBo, Gak The Korea Contents Association 2011 International Journal of Contents Vol.7 No.4

In this study, we investigated the effects of neuromuscular electrical stimulation (NMES) on the treatment of 20 acute stroke patients with dysphagia. For both the treated and control groups, the basic facial stimulation training was conducted for 30 minutes, five times a week, for four weeks. NMES was performed on the treated group only, for 30 minutes each time. Both groups were evaluated according to the functional dysphagia scale (FDS) using a videofluoroscopic swallowing study (VFSS). After the treatment was performed for four weeks, the FDS results of the treated group showed a significance difference in oral transit time in the oral phase and in the triggering of pharyngeal swallow fluid, laryngeal elevation and epiglottic closure, nasal penetration, residue in valleculae, coating of pharyngeal wall after swallow fluid, and pharyngeal transit time in the pharyngeal phase. In addition, the treated group showed a significant difference in laryngeal elevation and epiglottic closure, nasal penetration, and pharyngeal transit time in the pharyngeal phase after the treatment compared to the control group. The results of this study showed that neuromuscular electrical stimulation may be an effective method of treating dysphagia in acute phase stroke patients.

A Case of Capecitabine-Induced Sarcoidosis

Kang, Shin-Myung,Baek, Ji-Yeon,HwangBo, Bin,Kim, Hyae-Young,Lee, Geon-Kook,Lee, Hee-Seok The Korean Academy of Tuberculosis and Respiratory 2012 Tuberculosis and Respiratory Diseases Vol.72 No.3

Sarcoidosis is an inflammatory disease involving multiple-organs with an unknown cause. The new onset of sarcoidosis associated with therapeutic agents has been observed in 3 clinical settings; tumor necrosis factor antagonists in autoimmune rheumatologic diseases, interferon alpha with or without ribavirin in patients with chronic hepatitis C or melanoma, and antineoplastic agent-associated sarcoidosis in patients with hematologic malignancies. Here, we report a female patient who developed sarcoidosis after capecitabine treatment as an adjuvant chemotherapy for sigmoid colon cancer. To our knowledge, this is the first report of a capecitabine-induced sarcoidosis.

극 부호의 임계 집합 기반 비균일 분할 SC-Flip 복호 기법

황보찬(Chan Hwangbo),이우석(Useok Lee),노재홍(Jae Hong Roh),선우명훈(Myung Hoon Sunwoo) 대한전자공학회 2021 전자공학회논문지 Vol.58 No.7

극 부호는 Arıkan이 제안한 이산 비기억 채널에서 채널 용량을 달성할 수 있는 최초의 오류정정부호이며, 5G 표준의 제어채널 코딩 방식으로 채택되는 등 활발히 연구되고 있다. 그 중, 극 부호 복호기의 성능 향상을 위한 방법으로 SCF 알고리즘이 제안되었으며 우수한 오류정정 성능을 보여주지만, 신뢰도가 낮은 채널 환경에서 평균 복호 사이클이 크게 증가하는 단점이 있다. 본 논문에서는 기존 SCF 복호기의 지연시간 감소를 위해 임계 집합 분포를 분석하고, 이를 바탕으로 전체 부호어의 비균일 분할을 적용한 임계 집합 기반 비균일 분할 방법을 제안한다. 본 논문의 제안된 기법을 적용할 경우 SCL L=2와 유사한 FER 성능을 보이며, 지연시간 측면에서 기존의 SCF 및 분할된 SCF 복호기에 비해 T=16, SNR 1.0dB의 조건에서 각각 66.79% 및 10.77% 복호 클럭 사이클이 감소함을 확인하였다. Polar code proposed by Arıkan achieves channel capacity on a discrete memoryless channel and has been actively studied. In addition, it has been adopted as a channel coding scheme in the 5G standard. There are various studies to improve the performance and reduce the complexity of the decoder, and SCF algorithm shows the improvement of the error correction performance compared to SC algorithm. However, the SCF algorithm significantly increase the average clock cycle in low SNR channel environments. This paper proposes a critical set-based non-uniform segmentation SCF decoding algorithm by analyzing the distribution of critical sets and applying non-uniform segmentation of the entire codeword. The proposed algorithm shows a comparable FER performance with SCL(L=2). Compared to the conventional SCF and segmented SCF decoders, it reduces 66.79% and 10.77% decoding clock cycles at T=16 and SNR 1.0dB respectively.

Responses of Spinach (Spinacia oleracea L.) and Radish (Raphanus sativus L.) to Low Dose Gamma Radiation

Jun-Kwon Hwangbo(황보준권),Jae-Sung Kim(김재성),Ji Hyeok Lim(임지혁),Myung-Hwa Baek(백명화),Byung Yeoup Chung(정병엽),Jin-Hong Kim(김진홍) 한국원예학회 2003 한국원예학회 학술발표요지 Vol.2003 No.10

Growth and Mineral Contents of Spinach (Spinacia oleracea L.) and Radish (Raphanus sativus L.) as Related with a Low Dose Gamma Irradiation

( Jun Kwon Hwangbo ),( Jae Sung Kim ),( Ji Hyeok Lim ),( Myung Hwa Baek ),( Byung Yeoup Chung ),( Jin Hong Kim ) 한국환경생물학회 2003 환경생물 : 환경생물학회지 Vol.21 No.4

N/A This study was to evaluate the effects of gamma irradiation on the germination, nutrient concentrations and growth of spinach and radish. Both the spinach and radish seeds exhibited relatively higher germination rates in response to the low doses of gamma irradiation compared to the non-irradiated control. Leaf DW of the radish did not respond to gamma irradiation hut that of the spinach increased significantly in response to a gamma radiation of 4 Gy (P< 0.05). Leaf growth parameters of the spinach including the leaf area and SLA (leaf aredeaf dry weight) also demonstrated increased responses to gamma irradiation. USL (root dry weightkhoot dry weight), root DW and root length of the spinach exhibited a positive response to gamma irradiation while those of the radish did not. In contrast, SRL (root IengtWroot dry weight) significantly decreased with gamma irradiation at 8 Gy for the spinach, hut not for the radish. The tissue nitrogen concentrations of the spinach showed an increased response to gamma irradiation while that of the radish did not. Furthermore, higher concentrations of phosphorus, potassium, calcium and magnesium were found in the irradiated spinach, hut not in the irradiated radish. It seems that the non-specific physiological and/ or biochemical activities of spinach might he accelerated by gamma irradiation, possibly accounting for the stimulation of nutrient uptake from the root media and early bio-mass accumulation in the current study.