• Title/Summary/Keyword: biomedical

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A Digital Hearing Aid with 8-band Curvilinear Loudness Fitting (8대역 비선형 라우드니스 교정 디지털 보청기)

  • Park, Y.C.;Kim, D.W.;Kim, W.K.;Park, S.I.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.79-82
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    • 1997
  • In this paper, a body-worn type digital hearing aid (DHA) based on a dedicated DSP chip is developed. A fitting software running on a PC supported by the Win95 OS is also developed. The fitting protocol is based on the NAL-R procedure applied to eight frequency bands, but it is designed to support a curvilinear fitting to cope with the nonlinear perception of hearing-impaired listeners. Preliminary subjective tests regarding the speech intelligibility and perceived quality revealed that the new DHA could be of benefit to hearing aid users.

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R&D Trends of Brown Algae as Potential Candidates in Biomedical Application

  • Kim, Tae-Hee;Jung, Won-Kyo
    • Journal of Marine Bioscience and Biotechnology
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    • v.11 no.1
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    • pp.1-13
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    • 2019
  • Seaweeds contain various bioactive compounds. Especially, brown algae (Phaeophyceae), the second abundant group of seaweeds, contain numerous nutraceutical and pharmaceutical substances. In this review, we investigated on the brown algae-related patents and literature. Consequently, the research and development (R&D) trends of patent related to brown algae showed that the large majority was applied as the composition of stem cell culture medium and mostly used as active substances. In conclusion, we suggested that many researchers try to investigate and develop applications of brown algae as the sophisticated-level biomedical materials because brown algae are actively developing as simple-level biomedical materials.

Removal of Cerenkov Light in Fiber-optic Radiation Sensor Using Optical Filters (광학 필터를 이용한 광섬유 방사선 센서의 체렌코프 빛 제거)

  • Jang, Kyoung-Won;Lee, Bong-Soo;Cho, Dong-Hyun;Kim, Hyung-Shik;Yi, Jeong-Han;Lee, Jeong-Whan;Kim, Sin;Cho, Hyo-Sung
    • Korean Journal of Optics and Photonics
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    • v.17 no.4
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    • pp.312-316
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    • 2006
  • In this study, a miniature fiber-optic radiation sensor has been developed using a water-equivalent organic scintillator for electron beam therapy dosimetry. The intensity of Cerenkov light is measured and characterized as a function of the incident angle of the electron beam from a LINAC. Also, a subtraction method using a background optical fiber without a scintillator and an optical discrimination method using optical filters are investigated to remove Cerenkov light, which could cause problems or limit the accuracy for detecting a fluorescent light signal in a fiber-optic radiation sensor.

Feasibility study on the development of noncontact temperature sensor using infrared optical fiber (적외선 투과 광섬유를 이용한 비접촉식 온도 센서 개발을 위한 기초 연구)

  • Yoo, Wook-Jae;Cho, Dong-Hyun;Chung, Soon-Cheol;Tack, Gye-Rae;Jun, Jae-Hoon;Lee, Bong-Soo;Son, Sang-Hee;Cho, Seung-Hyun
    • Journal of Sensor Science and Technology
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    • v.15 no.3
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    • pp.179-185
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    • 2006
  • We have developed a noncontact temperature sensor using a silver halides infrared optical fiber. An infrared radiation from a heat source is transferred by a silver halides infrared optical fiber and measured by infrared sensors such as a thermopile and a thermal optical power-meter. The relationships between the temperature of a heat source and the output voltage of the thermopile and the optical power of a thermal optical power-meter are determined. The measurable temperature range using a thermopile and a thermal optical power-meter are from 100 to $750^{\circ}C$ and from 30 to $750^{\circ}C$ respectively. It is expected that a noncontact temperature sensor using infrared optical fiber can be developed for medical and industrial usages based on the results of this study.

Performance Evaluation of a Fiber-Optic Cerenkov Radiation Sensor System Using a Simulated Spent Fuel Assembly (사용후핵연료 집합체 모사장치를 이용한 광섬유 체렌코프 방사선 센서 시스템의 성능평가)

  • Shin, Sang Hun;Yoo, Wook Jae;Jang, Kyoung Won;Cho, Seunghyun;Park, Byung Gi;Lee, Bongsoo
    • Journal of Sensor Science and Technology
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    • v.23 no.4
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    • pp.245-250
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    • 2014
  • When the charged particle travels in transparent medium with a velocity greater than that of light in the same medium, the electromagnetic field close to the particle polarizes the medium along its path, and then the electrons in the atoms follow the waveform of the pulse which is called as Cerenkov light or radiation. This type of radiation can be easily observed in a spent fuel storage pit. In optical fibers, the Cerenkov light also can be generated due to their dielectric components. Accordingly, the radiation-induced light signals can be obtained using optical fibers without any scintillating material. In this study, to measure the intensities of Cerenkov radiation induced by gamma-rays, we have fabricated the fiber-optic Cerenkov radiation sensor system using silica optical fibers, plastic optical fibers, multi-anode photomultiplier tubes, simulated spent fuel assembly and a scanning system. To characterize the Cerenkov radiation generated in optical fibers, the intensities of Cerenkov radiation generated in the silica and plastic optical fibers were measured. Also, we measured the longitudinal distribution of gamma rays emitted from the Ir-192 isotope by using the fiber-optic Cerenkov radiation sensor system and simulated spent fuel assembly.

Identification of Differentially Expressed Genes in Human Small Cell Lung Carcinoma Using Subtractive Hybridization

  • Ahn Seung-Ju;Choi Jae-Kyoung;Joo Young Mi;Lee Min-A;Choi Pyung-Rak;Lee Yeong-Mi;Kim Myong-Shin;Kim So-Young;Jeon Eun-Hee;Min Byung-In;Kim Chong-Rak
    • Biomedical Science Letters
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    • v.10 no.3
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    • pp.195-202
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    • 2004
  • Lung cancer is a leading cause of cancer death worldwide; however, despite major advances in cancer treatment during the past two decades, the prognostic outcome of lung cancer patients has improved only minimally. This is largely due to the inadequacy of the traditional screening approach of diagnosis in lung cancer, which detects only well­established overt cancers and fails to identify precursor lesions in premalignant conditions of the bronchial tree. In recent years this situation has fundamentally changed with the identification of molecular abnormalities characteristic of premalignant changes; these concern tumour suppressor genes, loss of heterozygosity at crucial sites and activation of oncogenes. Basic knowledge at the molecular level has extremely important clinical implications with regard to early diagnosis, risk assessment and prevention, and therapeutic targets. In this study we used a 'cap-finder' subtractive hybridization method, 'long distance' polymerase chain reaction (PCR), streptavidin magnetic beads mediated subtraction, and spin column chromatography to detect differential expression genes of human small cell lung carcinoma. We have now isolated ninety two genes that expressed differentially in the human small cell lung carcinoma cells and analyzed of 12 clones with sequencing, nine cDNAs include tapasin (NGS-17) mRNA, BC200 alpha scRNA, chromosome 12q24 PAC RPCI3-462E2, protein phosphatase 1 (PPPICA), translocation protein 1 (TLOC1), ribosomal protein S24 (RPS24) mRNA, protein phosphatase (PPEF2), cathepsin Z, MDM2 gene and three novel genes. They may be oncogenesis­related proteins.

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