• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.48-53
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• 2004

Spectral irradiance measurement system was developed to measure the spectral irradiance of optical sources in the wavelength range from 250[nm] to 1600[nm]. Our system is composed of source system, fore-optics, monochromator system, optical detector system, and automatic control system. Optical detector system with PMT, Si, InGaAs, and IR enhanced InGaAs detectors is used to measure the wide spectrum of optical sources in ultraviolet visible, and infrared wavelength regions. Spectral irradiance of the 1[kW] quartz-halogen tungsten lamp was measured and compared in the wavelength range from 250[nm] to 1600[nm]. The differences between our results and those reported by NIST are below 3[%], 3.5[%], and 5[%] in the wavelength range of 450∼700[nm], 700∼1600[nm], 250∼400[nm], respectively.

• Korean Journal of Environmental Biology
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• v.21 no.1
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• pp.52-55
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• 2003

There is considerable evidence that ionizing radiation (IR) mediates checkpoint control, repair and cell death. In this study, we have used a high density microarray hybridization approach to characterize the transcriptional response of human breast carcinoma MCF-7 cell line to ${\gamma}$-radiation, such as 4 Gy 4 hr, 8 Gy 4 hr, and 8 Gy 12 hr. We found that exposure to ${\gamma}$-ray alters by at least a $log_2$ factor of 1.0 the expression of 115 known genes. Of the 66 genes affected by ${\gamma}$-radiation, 49 are down-regulated. In our results, the cellular response to irradiation includes induction of the c-jun and EGR1 early response genes. The present work has examined potential cytoplasmic signaling cascades that transduce IR-induced signals to the nucleus. 40S ribosomal protein s6 kinase modulates the activities of the mitogen activated protein kinase (MAPK) and c-Jun $NH_2$-terminal kinase (JNK1) cascades in human monocytic leukemia (U937/pREP4) cells. 14-3-3 family members are dimeric phosphoserine -binding proteins that participate in signal transduction and checkpoint control pathways.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.889-895
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• 2003

In this paper, we develop a PC adapter board and application software that do not use mouse or keyboard but the infrared communication, which can control the operation remotely. The infrared communication adapter is made up of the infrared receiver part and the serial communication interface part. The infrared receiver part creates a suitable scan-code using the received signal from the infrared transmitter (remote-controller). The serial communication interface part transmits the scan-code to PC by a serial communication. We implement its application softwares to listen to music and see movies. We can control their operations such as play, stop, pause and volume control remotely.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.5
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• pp.417-422
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• 2014

A guitar pickup is a transducer that converts string vibration to an electrical signal. The magnetic and piezo pickups are the most commonly used for the respective electric and electroacoustic guitars. The magnetic pickups are prone to magnetic interference between the steel strings and permanent magnets, while the piezo ones are not free from signal inference between the strings. Thus, this paper presents the development of an optical pickup for the electroacoustic guitar. The proposed optical pickup has the top-to-bottom structure. It uses two of Infrared (IR) Light Emitting Diode (LED) and one photodetector. The developed optical pickup is subjected to the evaluation with commonly used piezoelectric pickup. It becomes obvious that SNR with the optical pickup is increased by 45 percent in average, compared with the piezoelectric pickup. It can be concluded that the developed optical pickup has a potential to be applied to the acoustic guitar.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.6
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• pp.27-32
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• 2008

Impulse Radio Ultra Wide Band (IR-UWB) system can be used to wireless position location system because of its unique very short pulse in the order of nanosecond. A few algorithms have been proposed to calculate location of sensors or tags. In this paper, we compare these algorithms and propose 'TDoA with wireless synchronization' as practical solution. Earlier algorithms need special logic to fix the duration to receive and send pulse or assume synchronization with wire. In proposed method, beacons synchronize each other using impulse and nodes can be made simple and cheap. We evaluated the performance and it shows 50% improved accuracy at the error range of 50cm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4A
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• pp.302-308
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• 2009

In this paper, two receive diversity combining techniques are proposed for single-carrier Sequency division multiple access (SC-FDMA)-based cooperative relay systems when DFT spreading sizes for mobile station (MS) and relay station (RS) are different. A simplified-MRC (5-MRC) technique performs diversity combining in the time domain using the estimated channel weight and initial values obtained by SC-FDMA signal detection. An interference rejection-MRC (IR-MRC) technique performs diversity combining in the frequency domain by adjusting DFT spreading size in the receiver. It is shown by computer simulation that the proposed receive diversity combining techniques achieve a significant performance gain over the conventional MRC technique with zero forcing (ZF) detector.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.1
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• pp.98-105
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• 2007

In this paper, we propose a timing detector using suboptimal maximum likelihood method. The proposed method has an simple reference signal generator. Additionally, timing detector's gain of the proposed method is the same to Early-Late gate and ML method. We reveal that tracking range of time tracker is narrow because of using data-decision, that is, tracking range is ${\pm}0.06ns$ for the 4-order Gaussian monocycle with 0.7ns pulse width. Therefore we can find that searcher must have very accurate acquisition procedure. When estimating a performance of time tracker, we consider a jitter in transmitter and receiver's pulse generation process as well as background noise. By using computer simulation, we propose mean/variance of timing detector and tracking process. Also we consider a mobility in tracking process, i.e., timing error modeled ramp function. In order to propose a performance of time tracker, we consider only one correlation demodulator.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.5
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• pp.418-426
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• 2019

Recently, many studies on vital sign detection using a radar sensor related to Internet of Things(IoT) smart home systems have been conducted. Because vital signs such as respiration and cardiac rates generally cause micro-motions in the chest or back, the phase of the received echo signal from a target fluctuates according to the micro-motion. Therefore, vital signs are usually detected via spectral analysis of the phase. However, the probability of false alarms in cardiac rate detection increases as a result of various problems in the measurement environment, such as very weak phase fluctuations caused by the cardiac rate. Therefore, this study analyzes the difficulties of vital sign detection and proposes an efficient vital sign detection algorithm consisting of four main stages: 1) phase decomposition, 2) phase differentiation and filtering, 3) vital sign detection, and 4) reduction of the probability of false alarm. Experimental results using impulse-radio ultra-wideband radar show that the proposed algorithm is very efficient in terms of computation and accuracy.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.344-351
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• 2005

Nitric oxide (NO) and calcium-binding proteins occur in various types of cells in the central nervous system. They are important signaling and calcium buffering molecules, respectively. In the present study, using immunocytochemistry we examined the distribution and the co-localization pattern of neurons containing neuronal nitric oxide synthase (nNOS) and parvalbumin in the visual cortex of hamster. The overall number of parvalbumin-immunoreactive (IR) neurons was 17 times higher than that of the nNOS-IR neurons in the hamster visual cortex. The highest differences were found in layer V, where parvalbumin-IR neurons were 54.7 times more abundant than nNOS-IR neurons. Many nNOS- and parvalbumin-IR neurons were similar in size, shape, and manner of distribution in the visual cortex. However, two-color immunofluorescence revealed that no neurons in the hamster visual cortex expressed both nNOS and parvalbumin. The present results indicate that there are subtle species differences in the co-localization pattern between nNOS and calcium-binding proteins. The present results also suggest not only the heterogeneity and functional diversity of nNOS-IRneurons in the visual cortex, but also the importance of understanding animal diversity

• Food Science and Preservation
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• v.22 no.6
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• pp.893-900
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• 2015

In this study, we evaluated the antidiabetic effect of a submerged culture of Ceriporia lacerata mycelium (CL01) on hematological indices, as well as protein and mRNA expression of the insulin-signaling pathway, in db/db mice. After CL01 was administrated for 4 weeks, blood glucose levels decreased consistently, and plasma insulin and c-peptide levels each decreased by roughly 55.8%, 40% of those in the negative control (p<0.05). With regard to HOMA-IR, an insulin resistance index, insulin resistance of the CL01-fed group improved over that of the negative control group by about 62% (p<0.05). In addition, we demonstrated that the protein expression levels of pIR, pAkt, pAMPK, and GLUT4 and the mRNA expression levels of Akt2, IRS1, and GLUT4 in the muscle cells of db/db mice increased in the CL01-fed group compared to the corresponding levels in the control group. These results demonstrate that CL01 affects glucose metabolism, upregulates protein and gene expression in the insulin-signaling pathway, and decreases blood glucose levels effectively by improving insulin sensitivity. More than 90% of those who suffer from type 2 diabetes are more likely to suffer from hyperinsulinemia, hypertension, obesity, and other comorbidities because of insulin resistance. Therefore, it is possible that CL01 intake could be used as a fundamental treatment for type 2 diabetes by lowering insulin resistance, and these results may prove be useful as basic evidence for further research into the mechanisms of a cure for type 2 diabetes.