• Title/Summary/Keyword: Cricket

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Omnidirectional Distance Estimation using ultrasonic in Wireless Sensor Networks (무선 센서 네트워크에서 초음파를 이용한 전방향 거리 측정)

  • Lee, Woo-Sik;Kim, Nam-Gi
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.5
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    • pp.85-91
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    • 2009
  • Because ubiquitous environment has come with growing IT technology, Researches wireless sensor network are actively on going in many aspects. In this paper, we proposed simple method of distance measurement for omnidirectional distance calculation in wireless sensor network. In addition, we design and implement the proposed method. Then, we verify it through experiments at real environments. when we use the proposed method, maximum distance of measurement is decreased, but we measure distance from degrees. In this paper, we show drop rate and accuracy rate of ultrasonic distance estimation with and without omnidirectional device through experiments at real environments.

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Protective Effect of Gryllus Bimaculatus Methanol Extract on UVB-induced Photoaging in Human Skin Fibroblasts (UVB로 손상된 피부 섬유아세포에서 쌍별귀뚜라미 메탄올 추출물의 보호효과)

  • Jeong, Taekyoung;Yu, Myeongnam;Heo, Huijin;Yang, Jinwoo;Jeong, Heonsang;Lee, Junsoo
    • Journal of the Korean Society of Food Culture
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    • v.35 no.5
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    • pp.478-482
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    • 2020
  • We evaluated the protective effects of cricket methanol extract (CME) on ultra-violet B (UVB)-induced photoaging in human skin fibroblasts. The fibroblast cells were treated with 10, 50, and 100 ㎍/mL of CME for 24 h, and then exposed to UVB (30 mJ/㎠). CME showed a dose-dependent cytoprotective effect without any observable cytotoxicity. CME reduced UVB-induced production of reactive oxygen species (ROS) by 34.4, 34.9, 40.6% at concentrations of 10, 50, 100 ㎍/mL respectively. CME inhibited the release of matrix metalloproteinase (MMP) 1 and 3. Furthermore, CME also reduced UVB-induced collagen degradation in the fibroblast cells. Taken together, our data suggests that CME has a significant protective effect on UVB-induced photoaging of the skin. This benefit occurs through multiple mechanisms. The results also suggest a potential role for CME as an ingredient in anti-photoaging cosmetic products in the future.

Location Based Reminder on the Wireless LAN Environment (무선 LAN 환경에서의 위치기반 알리미)

  • Hong, In-Pyo;Park, Se-Jin;Kim, Min-Koo
    • 한국HCI학회:학술대회논문집
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    • 2007.02a
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    • pp.808-815
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    • 2007
  • 유비쿼터스 컴퓨팅에 대한 관심이 높아지면서, 위치인식기술의 중요성이 대두 되고 있다. 기존에 많이 이용되어 왔던 위치인식기술에는 인공위성을 이용한 GPS, 초음파를 이용한 Cricket, 적외선을 이용한 Active Badge, RF를 이용한 RFDAR등이 있다. 하지만 이러한 기술들은 시스템을 위해 기반 시설을 전제 조건으로 하기 때문에 이용에 어려움이 따른다. 기존의 위치인식기술의 단점을 보안하기 위한 방법으로 제시된 것이 GSM과 무선 LAN을 이용한 위치인식기술들이다. 현재는 차량용 네비게이션, 물류시스템의 상품 운반 현황 추적 등 위치인식기술을 바탕으로 한 다양한 서비스들이 상용화되어 가고 있다. 상용화된 서비스들의 특성에 따라 개인화된 위치 정보를 필요로 하는 것들이 많아 지고 있으며, 개인화된 정보를 획득하고 이를 서비스에 적용하려는 시도가 여러 곳에서 진행 중이다. 개인화된 정보를 얻기 위해서는 사람이 이해하고 사용할 수 있는 장소라는 개념을 확보해야 하며, 인공지능적인 기술들을 필요로 하게 된다. 본 논문에서는 기반시설(AP: Access Point)이 충분한 무선 LAN을 이용하여 위치인식 기술애 대해 연구하였다. 기존의 무선 LAN 장비를 통하여 얻어진 위치 데이터를 가공하여 검색 기술의 고전적인 방법인 벡터 유사도와 확률 기반 유사도를 적용하여 인식률의 추이를 실험해 보고, 인식률 증가를 위한 방법들을 모색해 보겠다. 또 위치기반 알리미를 통하여 개인화 정보에 대한 적용 방향에 대해 연구해 보고자 한다.

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A Method to Improve Location Estimation of Sensor Node (센서노드 위치 측정 정확도 향상 방법)

  • Han, Hyeun-Jin;Kwon, Tae-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.12B
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    • pp.1491-1497
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    • 2009
  • Existing methods to measure are based on ToA (Timer of Arrival), RSS (Received Signal Strength), AoA(Angle of Arrival) and other methods. In this paper, we propose a compensation of ToA and RSS methods to measure more precisely the distance of nodes. The comparison experiments with the traditional ToA method show that the average error value of proposed method is reduced 30%. We believe that this proposal can improve location estimation of sensor nodes in wireless sensor networks.

Seasonal Changes in Age Structure and Fecundity of the African Mole Cricket (Gryllotalpa africana) Population in Suwon, Korea (수원지방에서의 땅강아지 개체군 연령 분포의 계절적 변화와 산란수)

  • 김기황
    • Korean journal of applied entomology
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    • v.34 no.1
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    • pp.70-74
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    • 1995
  • A study on seasonal changes in age structure and fecundity of Gryllotalpa africana Palisot de Beauvois was conducted in Suwon from 1991 through 194. It seemed that most of newly hatched nymphs emerge to adults in September and October, so have a life cycle a year, and some overwinter as nymphs and emerge to adults from August, so have a life cycle tow years. The mean number of eggs per cell was $36.00\pm$2.84 for egg cells laid in the laboratory, and $47.68\pm$4.35 for egg cells collected in the field. Mean and range of the numbers of egg cells produced per female were $1.17\pm$0.19 and 0~3.

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Protective Effects of YCY against Hepatotoxicity Induced by 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) in Rats

  • Woon Kwon;Chai, Hee-youl;Young min Cho;Park, Ehn-kyoung;Kim, Ik-soo;Ryu, Kang-sun;Hwang, Seock-Yeon;Yun, Chi-Young;Kang, Jong-Koo
    • Proceedings of the Korean Society of Veterinary Pathology Conference
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    • 2003.10a
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    • pp.46-46
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    • 2003
  • Polychlorinated dibenzo-p-dioxins (PCDDs) are widespread, persistant, and highly toxic environmental pollutants. TCDD is the most potent congener among PCDDs and the most thoroughly investigated model compound of this class of chemicals. These compounds elicit a variety of common biochemical and toxic response, including specific binding to the cytosolic AHR [1] and induces a variety of biological response ranging from induction of cytochrome P-450 1A (CYP1A) to liver damage and cancer [2]. This study was carried out to investigate the protective effects of YCY, extract of a cricket, Gryllus bimaculatus, on hepatotoxicity in 6-week-old SD rat exposured to TCDD (omitted)

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Construction and Management of Heterogeneous Sensor Information for Healthcare Home Service (헬스케어 홈 서비스를 위한 이기종 센서 정보 구축 및 관리)

  • Lee, Chung-Sub;Yoon, Young-Min;Jeong, Chang-Won;Joo, Su-Chong
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.10a
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    • pp.209-213
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    • 2006
  • 기존 센서 데이터 처리를 위한 대부분의 연구는 특정응용 메커니즘을 갖는 중앙 집중형 구조를 사용하고 있다. 데이터는 미리 정의된 방법으로 수집되어 중앙 서버의 전형적인 DBMS에 의해 저장된다. 그러나 다양한 센서의 등장은 각 센서의 서로 다른 특성 때문에 기존의 방법으로는 센서로부터 수집된 데이터를 처리하거나 관리하기 어려운 문제점을 야기 시켰다. 따라서 본 논문에서는 이기종의 센서로부터 수집된 정보를 구축하고 이를 위해 우리가 그동안 연구한 헬스케어 프레임워크 기반에서 센서 매니저를 추가 구현하였다. 제안된 센서 매니저는 이기종의 센서로부터 수신된 스트림 형식의 데이터를 처리하고, 각 센서 데이터의 변화 정도에 따른 수집 주기 설정 및 데이터베이스에 저장하기 위한 기능을 포함하고 있다. 센서 매니저의 수행성을 검증하기 위해 Mica2 Mote와 Cricket 센서로부터 수집된 데이터 처리과정과 헬스케어 데이터베이스 관리 도구를 통해 데이터베이스에 저장된 정보를 확인하였다.

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Location Tracking System for Container Trailer Using Ubiquitous Sensor Networks (USN를 이용한 컨테이너 트레일러 위치추적 시스템)

  • Park, Jong-Hyun;Choo, Young-Yeol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.3
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    • pp.627-633
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    • 2007
  • This paper describes position tracking system of a container trailer approaching to a gantry crane for loading or unloading a container into or from a ship, respectively. Proposed position tracking system informs the trailer driver of right position to stop the car under a gantry crane. To measure the location of a trailer, we used Cricket Mote modules which adopted RF and ultrasound technology. We present an elaborate method to improve position errors occurring at sensing and calculate three dimensional position by triangulation along with how to reduce location tracking interval for real-time monitoring. The location information was transmitted to a Personal Digital Assistant (PDA) periodically through Bluetooth communication for guidance of the trailer driver. In indoor and outdoor tests, position errors were less than 3 cm and location tracking interval was 0.5 second on average.

Development of Convergence Study Program for Community Child Welfare Center linked Green Growth Using Pico-Cricket (피코크리켓을 활용한 지역아동센터의 녹색성장연계 융합프로그램의 개발)

  • Hur, Jung-Ho;Nam, Dong-Soo;Lee, Tae-Wuk
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.11
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    • pp.83-90
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    • 2010
  • In this paper, we developed the program related green growth based Educational-Robot in the framework of Convergence for the community child welfare centers' children who are in poverty and broken homes as the way to enhance the competitiveness about education and a solution to cope with actively about the main tasks of the state for human resources in the future. Through the program developed, it has been verified the impact on the energy saving attitude. According to this result, it has been proved that convergence study program linked green growth for children of community welfare child center is effective to energy saving attitude. Through it, it is expected to help to meet the educational needs of the community child welfare centers' children.

Mitochondrial DNA Sequence Variation of the Oriental Mole Cricket, Gryllotalpa orientalis (Orthoptera: Gryllotalpidae) in Korea

  • Kim, Ik-Soo;Cha, So-Young;Lee, Sun-Young;Kim, Seong-Ryul;Hwang, Jae-Sam;Li, Jianhong;Han, Yeon-Soo;Jin, Byung-Rae
    • International Journal of Industrial Entomology and Biomaterials
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    • v.14 no.2
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    • pp.107-112
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    • 2007
  • The mole crickets, Gryllotalpa, are insect pest distributed in the world. In Korea, G. orientalis was reported to occur, but previous ecological studies suggested the presence of two ecological types. To test this hypothesis, we sequenced a portion of mitochondrial (mt) genome from 48 G. orientali individuals collected over five Korean localities: Busan, Suwon, Okchon, Wonju, and Gangneung. From the sequence analysis, only two haplotypes were obtained, but the sequence divergence between the two haplotypes was 11 %, suggesting the presence of two distinct genetic groups in Korea. Although the population of Busan, Okchon, Wonju, and Gangneung was identified as a single haplotype, but that of Suwon was occupied by both hapotypes. Considering sequence divergence of other insect species occurring in Korea, the divergence estimate found between the two haplotypes seems to be too large to be considered as identical species. This result may suggest that the two differentiated haplotypes found in this study may reflect the previously reported two ecological types found in Suwon, Korea. To further understand the genetic divergence of the two phylogenetic groups, analysis of more variable regions of G. orientalis genome is required.