에너지 수집형 무선 센서 네트워크에서 선택적 데이터 압축을 통한 동적 센싱 주기 제어 기법

윤익준,이준민,정세미,전준민,노동건,Yoon, Ikjune,Yi, Jun Min,Jeong, Semi,Jeon, Joonmin,Noh, Dong Kun 대한임베디드공학회 2016 대한임베디드공학회논문지 Vol.11 No.2

In wireless sensor networks, increasing the sensing rate of each node to improve the data accuracy usually incurs a decrease of network lifetime. In this study, an energy-adaptive data compression scheme is proposed to efficiently control the sensing rate in an energy-harvesting wireless sensor network (WSN). In the proposed scheme, by utilizing the surplus energy effectively for the data compression, each node can increase the sensing rate without any rise of blackout time. Simulation result verifies that the proposed scheme gathers more amount of sensory data per unit time with lower number of blackout nodes than the other compression schemes for WSN.

장기간 지팡이의 사용이 뇌졸중 환자의 건측 상지 기능에 미치는 영향

손성민,최용원,김중선,Son, Sung-Min,Choi, Yong-Won,Kim, Chung-Sun 대한물리치료학회 2012 대한물리치료학회지 Vol.24 No.2

Purpose: The purpose of this study was to investigate the adverse effects of sensorimotor function at the shoulder joint according to long-term cane usage in stroke patients without apraxic behavior, in terms of the presence of shoulder joint pain, accuracy of tracking task, proprioceptive joint position sense, and nine-hole pegboard. Methods: Nineteen stroke patients with long-term cane usage (cane usage group) and nineteen stroke patients without cane usage (non-cane usage group) were recruited. All subjects were tested in pain presence, a tracking task for visuomotor function, joint reposition, and nine-hole pegboard in the shoulder joint regarding the non-affected side. Results: In the accuracy index for tracking task and the nine-hole pegboard test, significant differences were observed between the cane usage group and the non-cane usage group. However, although a higher emergence of shoulder pain and a lower accuracy for joint reposition sense were detected in the cane usage group in comparison to the non-cane usage group, there were no significant differences between the two groups. Conclusion: Our findings suggest that long-term cane usage could induce to decrease in delicate movement and coordination in the non-affected upper arm in stroke patients. In addition, they could experience high frequency of shoulder pain and poor joint reposition sense. Therefore, careful evaluation and observation will be required concerning stroke patients with long-term cane usage.

GIS와 원격탐사자료를 이용한 산림전용지 추출 및 정확도 평가

이기행 ( Gi Haeng Lee ),이정수 ( Jung Soo Lee ) 한국임학회 2012 한국산림과학회지 Vol.101 No.3

본 연구는 원주시를 대상으로 중해상도 위성영상을 이용하여 산림전용지의 추출 및 정확도 분석을 목적으 로 수행하였다. 2000년부터 2008년까지 산림에서 비산림으로 전용된 면적은 467 ha로 연평균 약 52 ha가 전용되었 으며, 전용형태는 주거지로의 전용이 약 72% 차지하였으며, 전체발생면적의 약 97%가 2 ha 미만이였다. 또한, 산림 전용지는 도로로부터 500 m이내와 산림·비산림 경계로부터 100 m이내 지역에서 약 79%가 발생하였다. 한편, 행 정정보상의 산림전용지(GIS전용지)와 위성영상에 의하여 구축된 지수별(NDVI, NBR, NDWI) 산림전용지(RS전용지)와 비교한 결과, 추출정확도는 3×3 필터링을 적용한 NDVI의 평균(u)-표준편차(σ)×1.5 구간에서 일치율 35.47%, K-지수 0.20로 가장 안정적인 정확도를 나타냈다. 정확도 오차의 원인으로는 산림전용지의 토지이용변화와 토지피복변화의 불일치로서, 행정정보상의 산림전용지의 실제 토지피복변화율은 약 32%에 지나지 않았다. 또한, RS전용지에 의하여 산림경영활동지역의 약 7.52%가 산림전용지로 오류 추출되었다. 토지이용 및 토지피복상 변화된 산림전용지(GIS전 용지2)를 대상으로 지수별 RS전용지와 정확도를 비교한 결과, 3×3 필터링을 적용한 NDVI의 u-σ×2 구간에서 일치 율 61.23%, K-지수 0.23으로 향상되었다. This study purposed to extract and assess the accuracy of assessment for deforestation area in Wonju city using medium resolution satellite image. The total size of deforestation area during the last nine years (2000-2008) was about 467 ha, and it was occurred annually about 52 ha. The most frequent form of deforestation was settlements (72%). Ninety percent of the size of deforestation was less than 2 ha in size. In addition, 79 percent of deforestation area was found within 500 m from the road network and within 100 m of the Forest/Non-forest boundary. This study compared the deforestation based on the administrative information (GIS deforestationI) with the deforestation (RS deforestation) extracted from the satellite imagery by vegetation indices (NDVI, NBR, NDWI). Extraction accuracy, mean-standard deviation×1.5 applied 3 by 3 filtering, showed reliable accuracy 35.47% k-value 0.20. However, error could be occurred because of the difference of land-use change and landcover change. The actual rate of land-cover change deforestation area was 32% on administrative information. The 7.52% of forest management activities area was misjudged as deforestation by RS deforestation. Finally, the comparison of land-cover change deforestation (GIS deforestationII) with the RS deforestation accuracy, as a result NDVI mean-standard deviation×2 applied 3 by 3 filtering, showed improved accuracy 61.23%, k-value 0.23.

Automotive High Side Switch Driver IC for Current Sensing Accuracy Improvement with Reverse Battery Protection

Park, Jaehyun,Park, Shihong The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.5

This paper presents a high-side switch driver IC capable of improving the current sensing accuracy and providing reverse battery protection. Power semiconductor switches used to replace relay switches are encumbered by two disadvantages: they are prone to current sensing errors and they require additional external protection circuits for reverse battery protection. The proposed IC integrates a gate driver and current sensing blocks, thus compensating for these two disadvantages with a single IC. A p-sub-based 90-V $0.13-{\mu}m$ bipolar-CMOS-DMOS (BCD) process is used for the design and fabrication of the proposed IC. The current sensing accuracy (error ${\leq}{\pm}5%$ in the range of 0.1 A-6.5 A) and the reverse battery protection features of the proposed IC were experimentally tested and verified.

Automotive High Side Switch Driver IC for Current Sensing Accuracy Improvement with Reverse Battery Protection

Jaehyun Park,Shihong Park 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.5

This paper presents a high-side switch driver IC capable of improving the current sensing accuracy and providing reverse battery protection. Power semiconductor switches used to replace relay switches are encumbered by two disadvantages: they are prone to current sensing errors and they require additional external protection circuits for reverse battery protection. The proposed IC integrates a gate driver and current sensing blocks, thus compensating for these two disadvantages with a single IC. A p-sub-based 90-V 0.13-μm bipolar-CMOS-DMOS (BCD) process is used for the design and fabrication of the proposed IC. The current sensing accuracy (error ≤ ±5% in the range of 0.1 A–6.5 A) and the reverse battery protection features of the proposed IC were experimentally tested and verified.

Automotive High Side Switch Driver IC for Current Sensing Accuracy Improvement with Reverse Battery Protection

박재현,박시홍 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.5

This paper presents a high-side switch driver IC capable of improving the current sensing accuracy and providing reverse battery protection. Power semiconductor switches used to replace relay switches are encumbered by two disadvantages: they are prone to current sensing errors and they require additional external protection circuits for reverse battery protection. The proposed IC integrates a gate driver and current sensing blocks, thus compensating for these two disadvantages with a single IC. A p-sub-based 90-V 0.13-μm bipolar-CMOS-DMOS (BCD) process is used for the design and fabrication of the proposed IC. The current sensing accuracy (error ≤ ±5% in the range of 0.1 A–6.5 A) and the reverse battery protection features of the proposed IC were experimentally tested and verified.

Comparison of Visual Interpretation and Image Classification of Satellite Data

In Soo Lee,Dong Hoon Shin,Seung Mahn Ahn,Kyoo Seock Lee,Seong Woo Jeon 大韓遠隔探査學會 2002 大韓遠隔探査學會誌 Vol.18 No.3

The land uses of Korean peninsula are very complicated and high-density. Therefore, the image classification using coarse resolution satellite images may not provide good results for the land cover classification. The purpose of this paper is to compare the classification accuracy of visual interpretation with that of digital image classification of satellite remote sensing data such as 20m SPOT and 30m TM. In this study, hybrid classification was used. Classification accuracy was assessed by comparing each classification result with reference data obtained from KOMPSAT-1 EOC imagery, air photos, and field surveys.

Comparison of Visual Interpretation and Image Classification of Satellite Data

Lee, In-Soo,Shin, Dong-Hoon,Ahn, Seung-Mahn,Lee, Kyoo-Seock,Jeon, Seong-Woo The Korean Society of Remote Sensing 2002 大韓遠隔探査學會誌 Vol.18 No.3

The land uses of Korean peninsula are very complicated and high-density. Therefore, the image classification using coarse resolution satellite images may not provide good results for the land cover classification. The purpose of this paper is to compare the classification accuracy of visual interpretation with that of digital image classification of satellite remote sensing data such as 20m SPOT and 30m TM. In this study, hybrid classification was used. Classification accuracy was assessed by comparing each classification result with reference data obtained from KOMPSAT-1 EOC imagery, air photos, and field surveys.

웨어러블 기기를 활용한 생체 데이터의 정확도 측정 및 개선 연구

최희연(Choi Hee Yeon),노영태(Youngtae Noh) 한국정보기술학회 2021 Proceedings of KIIT Conference Vol.2021 No.11

피트니스와 웰빙에 대한 관심이 증가함에 따라 웨어러블 기기에 대한 수요가 높아지는 요즘, 스마트 워치의 PPG 센서의 정확도를 높이는 것은 주요 문제 중 하나이다. 본 논문에서는 다양한 조건에서 스마트 워치의 PPG 센서 정확도를 ECG 센서 값과의 비교를 통해 측정한다. As interest in fitness and well-being increases, demand for wearable devices increases, and increasing the accuracy of PPG sensors in smartwatches is one of the main problems. In this paper, the PPG sensor accuracy of the smartwatch is measured through comparison with the ECG sensor value under various conditions.

정전분말코팅 조건에 따른 3D 스캐닝 데이터의 민감도 특성 연구

맹희영,이주봉,김성민 한국전시산업융합연구원 2017 한국과학예술융합학회 Vol.29 No.-

surface to collect the 3D data using an optical 3D scanning device, like metal, rubber, glass materials. Currently, a developing solution is applied to eliminate the reflection of light of a material of a subject, but in the case of a developing solution, it is not only a consumable item but also a subject can be damaged, and it is difficult to remove it after coating. So that, an electro-static powder coating system is developed in this study that can be used as a substitute for the developing solution, and designed the system of the equipment in order to adsorb the electrostatic powder. The system of the electrostatic powder adsorption apparatus for three-dimensional photography is roughly classified into six parts, and includes an injection part for generating powder and voltage and a removal part for collecting and reusing powder sprayed on the subject It is a core part of the equipment system, and in other parts it is divided into a table of subjects, a control unit, a powder storage unit, and an air supply unit. After developing the equipment system, we analyzed and evaluated the data through 3D photography. Evaluation of the shape accuracy of the subject surface and the sensitivity characteristics of the three dimensional data were carried out. As a result, it was verified that the electrostatic powder coating method is more efficient than the developing solution application. In addition to being superior in terms of time and workers, the precision of three-dimensional data was more precisely known than with the developer coating. 백색광 3D 스캐너를 이용하여 금속이나 고무, 유리재질과 같이 매질 표면에서 빛이 난반사나 흡수 또는산란을 일으키는 표면 부위는 스캐닝 데이터의 손실이나 오류를 일으키기 때문에 데이터 수집이 어렵다. 이들 표면은 전통적으로 현상액을 도포하여 난반사가일어나지 않도록 스캐닝하고 있지만 부식이나 변색을유발시킬 수 있으며, 도포 후 완벽하게 세척할 수 없는 어려운 점이 있다. 본 연구에서는 이러한 문제점을 해결하기 위한 장치로서, 정전분말코팅의 원리를 이용하여 3차원 형상 측정을 위한 스캐닝 대상 표면에 정전기를 갖는 분말 입자들이 정전기의 힘으로 얇으면서도 고르게 코팅되도록 하기 위한 장치를 개발하였으며, 이 시스템을 이용하여 난반사 표면에 대한 3D 스캐닝 데이터를 얻을 때생기는 오류를 얼마만큼 줄일 수 있는가를 평가하였다. 피사체 표면에서 빛의 영향으로 데이터의 오류가 나타날 수 있는 3D 데이터의 민감도 특성에 대한 평가와 정전분말 코팅된 표면의 형상정밀도를 분석하였다. 무코팅, 현상액 도포, 정전분말코팅 등의 3가지 경우에 대한 스캔 데이터와 스캐닝 조건 등을 비교한결과, 금속 재질뿐만이 아니라 목재, 고무, 아크릴 등의 부도전체에서도 정전분말코팅의 조건이 3D 데이터수집의 민감도를 높여 주고 있으며, 빛이 흡수되거나고무 재질이나 투과되는 아크릴 재질에 있어서도 전반적으로 민감도는 우수해 짐을 밝힐 수 있었다. 또한 3D 스캔 데이터의 형상정밀도를 평가한 결과에 있어서는 일반적으로 코팅에 따른 형상정밀도의 향상은 투과성을 가진 유리 재질의 경우가 가장 적게 향상되고 있었으며, 금속의 경우보다는 비도전체의 경우가 그 차이가 크게 나타나지 않음도 밝힐 수 있었다