• Journal of Sensor Science and Technology
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• v.25 no.5
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• pp.337-343
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• 2016

In this paper, we newly introduce a wireless identification system using a solar cell and RF transceivers. The reader sends interrogating signal to a transponder using LED visible light, and the transponder responds to the reader using RF signal. The transponder consists of a solar cell, an amplifier, a microprocessor, and an RF transmitter. The solar cell receives the visible light from the reader and generates current to supply electric power to the other devices in the transponder. At the same time, the solar cell detects interrogating signal in the reader light. The microprocessor senses the interrogating signal and generates a responding signal. The RF transmitter radiates the responding signal to the reader. The transponder is a passive circuit because it operates without external power. In experiments, the maximum read distance between a reader and a transponder was about 1.6 meter.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.193-206
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• 2002

A signal optimization model is proposed by applying the Cell-Transmission Model(CTM) as an embedded traffic flow model to estimate a system-optimal signal timing plan in a transportation network composed of signalized intersections. Beyond the existing signal-optimization models, the CTM provides appropriate theoretical and practical backgrounds to simulate oversaturation phenomena such as shockwave, queue length, and spillback. The model is formulated on the Mixed-Integer Programming(MIP) theory. The proposed model implies a system-optimal in a sense that traffic demand and signal system cooperate to minimize the traffic network cost: the demand departing from origins through route choice behavior until arriving at destinations and the signal system by calculating optimal signal timings considering the movement of these demand. The potential of model's practical application is demonstrated through a comparison study of two signal control strategies: optimal and fixed signal controls.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.52-55
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• 2002

Flow cytometric techniques were used to investigate cell size, protein content and cell cycle behavior of recombinant Saccharomyces cerevisiae strains producing human lysozyme (HLZ). Two different signal sequences, the native yeast $MF\alpha1$ signal sequence and the rat $\alpha-amylase$ signal sequence, were used for secretion of HLZ. The strain containing the rat $\alpha-amylase$ signal sequence showed a higher level of internal lysozyme and lower specific growth rates. Flow cytometric analysis of the total protein content and cell size showed the strain harboring the native yeast signal sequence had a higher total protein content than the strain containing the rat $\alpha-amylase$ signal sequence. Cell cycle analysis indicated that the two lysozyme producing recombinant strains had an increased number of cells in the $G_2+M$ phase of the yeast cell cycle compared with the host strain SEY2102.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.329-334
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• 1999

Recently, cellular signal transduction mechanisms are greatly understood. However, bone cell signaling is not completely characterized. Interestingly, bone cells synthesize a number of growth factors such as IGF-I PDGF, IGF-II etc., suggesting these growth factors play important roles in bone cell signaling. In the present study, potential roles of nitric oxide (NO) and protein kinases in osteoblast signal transduction are proposed.

• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.49.1-49.1
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• 1998

• Proceedings of the IEEK Conference
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• summer
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• pp.27-30
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• 2004

OFDMA is considered as one of the major candidates for broadband wireless access. The OFDMA signal is usually coherently demodulated, requiring the channel estimation which can be estimated using a known pilot signal. In multi-cell environment, the performance of channel estimation is mainly limited by intercell interference. It is desirable to use a pilot signal that can estimate the channel information robust to the intercell interference in the OFDMA uplink system. In this paper, we consider two types of pilot signal applicable to multi-cell OFDMA uplink systems: One is time-multiplexed pilot signal and the other is code­multiplexed pilot signal. Simulation results show that the code-multiplexed pilot is suitable for low mobility environment and time-multiplexed pilot is suitable for high mobility environment.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9791-9795
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• 2014

To study the gene expression change and possible signal pathway during androgen-dependent prostate cancer (ADPC) becoming androgen-independent prostate cancer (AIPC), an LNCaP cell model of AIPC was established using flutamide in combination with androgen-free environment inducement, and differential expression genes were screened by microarray. Then the biological process, molecular function and KEGG pathway of differential expression genes are analyzed by Molecule Annotation System (MAS). By comparison of 12,207 expression genes, 347 expression genes were acquired, of which 156 were up-ragulated and 191 down-regulated. After analyzing the biological process and molecule function of differential expression genes, these genes are found to play crucial roles in cell proliferation, differntiation, cell cycle control, protein metabolism and modification and other biological process, serve as signal molecules, enzymes, peptide hormones, cytokines, cytoskeletal proteins and adhesion molecules. The analysis of KEGG show that the relevant genes of AIPC transformation participate in glutathione metabolism, cell cycle, P53 signal pathway, cytochrome P450 metabolism, Hedgehog signal pathway, MAPK signal pathway, adipocytokines signal pathway, PPAR signal pathway, TGF-${\beta}$ signal pathway and JAK-STAT signal pathway. In conclusion, during the process of ADPC becoming AIPC, it is not only one specific gene or pathway, but multiple genes and pathways that change. The findings above lay the foundation for study of AIPC mechanism and development of AIPC targeting drugs.

• Korean Journal of Optics and Photonics
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• v.29 no.6
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• pp.247-252
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• 2018

We report amplification of a small signal in a diode-pumped Cs vapor cell with 500 torr of ethane buffer gas, in the low-pump-power regime of 200 mW or less. For efficient amplifier operation, the pump and signal beams were coupled to a single-mode optical fiber, and completely overlapped in the Cs vapor cell. We investigated the amplification of the small signal according to cell temperature, signal power, and pump power. An amplification factor of 56 was achieved under the conditions of cell temperature of $115^{\circ}C$, signal power of 0.1 mW, and pump power of 200 mW.

• Archives of Pharmacal Research
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• v.25 no.1
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• pp.1-10
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• 2002

Attempts to develop drugs, specific for cancer cells, are dealt here according to the intended cell-target. While many target specific drugs were developed, they reach only moderate successes in clinics for reasons, such as, delivery problem, lack of in vivo efficacy or toxicity. However, recent efforts focusing on the diversity of tyrosine kinases, participating in cell-signal transduction, brought fruit. The first such drug, Givec, approved by the USFDA recently, is used in clinics with great success to threat CML. The drug inhibits tyrosin kinase of bcr-abl, c-abl and v-abl. Work is progressing on other tyrosin kinase inhibitors and on other type of specific cancer cell signal protein inhibitors. These efforts are hoped to yield better cures for cancer in the near future.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.593-595
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• 2020

본 논문에서는 5G NR 시스템을 위한 동기 신호를 이용한 cell ID 검출 방법에 대한 성능을 비교하였다. 5G NR(fifth-generation new radio) 시스템의 송신기는 SS/PBCH (synchronization signal/physical broadcast channel) 블록을 송신하며, 수신기는 수신된 SS/PBCH 블록을 이용하여 주파수 및 타이밍 오프셋 (frequency and timing offset)을 추정 할 수 있으며, cell ID (cell identity)는 PSS (primary synchronization signal)와 SSS (secondary synchronization signal)를 통해 검출할 수 있다. 본 논문에서는 cell ID 를 검출할 수 있는 방법으로서 2-stage 디코딩 방법과 결합 최대우도 결정 규칙 (joint maximum-likelihood decision rule: joint ML) 디코딩 방법을 사용하였다. Joint ML 디코딩 방법은 2-stage 디코딩 방법에 비해 더 좋은 검출 성능을 보이지만, 복잡도 측면에서는 2-stage 디코딩 방법이 joint ML 디코딩 방법에 비해 더 낮은 복잡도를 갖는 것을 확인하였다.