• ALGAE
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• v.37 no.4
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• pp.281-291
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• 2022

Quantifying the abundance of Chattonella species is necessary to effectively manage the threats from ichthyotoxic raphidophytes, which can cause large-scale mortality of aquacultured fish in temperate waters. The identification and cell counting of Chattonella species have been conducted primarily on living cells without fixation by light microscopy because routine fixatives do not retain their morphological features. Species belonging to the Chattonella marina complex, including C. marina and C. marina var. ovata, had high genetic similarities and the lack of clear morphological delimitations between the species. To estimate the abundance of C. marina complex in marine plankton samples, we developed a protocol based on the droplet digital polymerase chain reaction (ddPCR) assay, with C. marina complex-specific primers targeting the internal transcribed spacer (ITS) region of the rDNA. Cell abundance of the C. marina complex can be determined using the ITS copy number per cell, ranging from 25 ± 1 for C. marina to 112 ± 7 for C. marina var. ovata. There were no significant differences in ITS copies estimated by the ddPCR assay between environmental DNA samples from various localities spiked with the same number of cells of culture strains. This approach can be employed to improve the monitoring efficiency of various marine protists and to support the implementation of management for harmful algal blooms, which are difficult to analyze using microscopy alone.

• Radiation Oncology Journal
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• v.7 no.1
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• pp.1-13
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• 1989

Effects of ionizing radiation alone and combined with chemotherapy on tumor growth and it's clonal specificity monitored by changes in distribution of chromosome number were studies in A549 ceil line originated from human adenocarcinoma of the lung. Radiation (300 rad, 600 rad and 900 rad) were delivered with or without 5-FU. Forty eight hours later, 57.5% of growth inhibition of cell w8s seen in cells treated with 5-FU concentration of $0.4{\mu}g/ml$ for 24hr exposure. Cell survival curves after radiation with and without 5-FU were made. Chromosomal analysis of cells in metaphase in control, and in cells treated with 300 rad of radiation, or $0.4{\mu}g/ml$ of 5-FU treatment, and combined treatment of both were done to examine the changes in ploidy and number of chromosome. Radiation combined with S-FU enhanced growth inhibition of A549 cells. However, no evidence of synergegic effects in growth. inhibition was observed in the cells treated with the combination therapy. Pattern of chromosomal distribution of survived cells were shifted from hyperploidy to hypoploidy by single dose of radiation (300 rad). As radiation dose increased a large number of hypoploidy cells were observed. Following treatment of cells with 5-FU, chomosomal distribution of survived cells were also shifted to hypodiploidy which were seen in cells treated with radiation, The ceil treated with 5-FU and fellowed by radiation within 24 hrs had cell with increased number of hypodiploidy cells. Almost same type of chromosomal changes were reproduced in cells treated with combined treatment with radiation and 5-FU. Minor differences were that cells with fewer number of chromosome were more frequent in cells treated with combined therapy. Further increase in cells of hypoploidy (93%) having 1-10 chromosome were induced by additional radiation. Therefore, the enhanced therapeutic effect of 5-FU combined with radiation of A549 cells appeared to be additive rather than synergistic.

• Journal of the Korean Operations Research and Management Science Society
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• v.31 no.3
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• pp.1-10
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• 2006

In this paper we deal with a cell planning issue arisen in a CDMA based multicast network. In a CDMA based wireless network, a terminal can significantly reduce the bit error rate via the cohesion of data streams from multiple base stations. In this case, multiple base stations have to be operated according to a common time line. The cells whose base stations are operated as such are called soft-combined cells. Therefore, a terminal can take advantage of error rate reduction, if the terminal is in a soft-combined cell and at least one neighboring cell is also soft-combined. However, as soft-combining operation gives heavy burden to the network controller, the limited number of cells can be soft-combined. Our problem us to find a limited number of soft-combined cells such that the benefit of the soft-combining operation is maximized.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.74-74
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• 2003

Embryonic stem cells have several characteristics suitable for cell replacement therapy. To investigate a possibility of using human embryonic stem cell (hESC) as a carrier of therapeutic gene(s), hESC (MB03) was co-transfected with cDNAS coding for tyrosine hydroxylase (TH) and GTP cyclohydrolase Ⅰ (GTPCH Ⅰ) and bulk-selected using neomycin and hygromycin-B. Successful transfection was confirmed by western immunoblotting and RT-PCR. The genetically modified hESC (bk-THGC) relieved apomorphine-induced asymmetric motor behavior by approximately 54% when grafted into striatum of 6-OHDA-denervated rat brain. The number of rotation, however, increased up to 176+18% in 6 weeks when sham-grafted compared with number of rotation before graft. Immunohistochemical staining revealed that the grafted hESC survived and expressed TH for at least 6 weeks while the experiment was continued.

• Korean Management Science Review
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• v.12 no.1
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• pp.1-17
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• 1995

The success of cell manufacturing applications in FMS rests on the effective cell formation to maintain the independent relations both between machine cells and between part families. This paper presents an integrated method for concurrent formation of cells and families with no E.E (Exceptional Element) in FMS with alternative routings. To determine the maximum number of cell and family with no E.E, mathematical conditions and properties are derived. New concept of nonsimilarity is introduced for each machine and part based on machine-operation incidence matrix and part-operation incidence matrix. To concurrently form the cells and families, integer programming based mathematical models are developed. For the predetermined number of cell or family, model I is used to identify whether E.E exists or not. Model II forms cells and families considering only nonsimilarity. But model III can consider nonsimilarity and processing times. The proposed method is tested and proved by using numerical examples.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3154-3164
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• 1996

A major concern in a cellular mobile communication system is how to efficiently utilize the limited amount of frequencies. Various channel assignment methods and traffic sharing schemes have been proposed to improve system performance. However, these approaches suffer from complicated software and hardware requirements due to increased amount of traffic control In this paper, we propose a new method for improving system performance by controlling the powers of the set-up and voice channels of each cell site. We first show that the average number of blocked calls in a system is minimized when the traffic reates are made identical for all cell sites in a system. This result, together with the relationship between the channel powers and the service area, is used to determine the appropriate channel powers of each cell site. We also determine the upper limit on the channel power of each cell site considering co-channel interference and numerically show that the proposed method is effective in reducing the number of blocked calls without an excessive increase in the amount of system control.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.40-43
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• 2000

This paper is concerned with development of an efficient Ρ-median approach applicable to large cell formation(CF) problems. A two-phase methodology that seeks to minimize the number of exceptional elements is proposed. In phase I, two efficient Ρ-median formulations which contain fewer binary variables than existing Ρ-median formulations are constructed. These make it possible to implement large CF problem within reasonable computer runtime with commercially available linear integer programming codes. Given the initial cell configuration found with the new p-median formulations, in phase II bottleneck machines and parts are reassigned to reduce the number of exceptional elements. This procedure has the flexibility to provide the cell designer with alternative solutions. Test results on large CF problems show a substantial efficiency of the new Ρ-median formulations.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.754-758
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• 2002

In the fuel-cell electric vehicle system, the low-voltage output of unit fuel-cell demands a number of cells to be stacked In series to produce a DC link voltage which is high enough to drive the vehicle inverter system. However, this increases the complexity of the fuel-cell control system. This paper presents a design of high-efficiency boost converter employing the average current-mode control, which is able to convert a low voltage of a fuel-cell generator with a small number of unit cells to a stable and high DC link voltage for electric vehicle applications.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.6
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• pp.9-17
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• 1994

ATM (Asynchronous Transfer Mode) has a fixed-length packet transport scheme. It is one of the promising proposals in B-ISDN.Since the packet length is fixed, it can be potentially to perform the various service to users. In this paper, a queueing model for an ATM multip`exer loaded by CBR and ON/OFF input sources is considered, and the two-queue system which each type of input sources has a queue with a finite capacity is analyzed. The cell loss probabilities for a performance measures of ATM multiplexer are derived, and are also evaluated through numerical examples. As a result, the cell loss probability of ON/OFF sources for the queue size is rapidly decreased when the multiplexed number and burstiness are increased. Since cells of the CBR source have lower priority than cells of the ON/OFF source, cell loss probabilities of CBR sources are accordingly high independently of CBR cell arrival rate when the number of CBR sources is large.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.6
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• pp.492-498
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• 2009

Six sigma methode was applied for optimization of flow field design of a proton exchange membrane fuel cell (PEMFC). The optimization between number of channel and channel/rib width was suggested in this paper with six sigma method. With the help of six sigma design of experiment (DOE) the number of experiments may be reduced dramatically. The fuel cell channel design optimization with results of these experiments with a 100 $cm^2$ serpentine flow field indicates a optimization data for a given constant operating conditions.