• Progress in Medical Physics
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• v.9 no.1
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• pp.29-35
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• 1998

There has been necessity of an air free ionization chamber using the gold-crystal-aluminium plates, henceforth called the crystal chamber. The crystal chamber formed of parallel plates is very small in size and has more response for absorbed dose of therapeutic radiation beams. The gold plate on the crystal facing the photon and electron beam acts as an intensifier of signals and crystal plate as an ionization medium respectively. Both the copper guard ring and the aluminum collecting electrode are connected to an electrometer. Using high energy photon (6, 15 MV) and electron (9, 12, 15, 18 MeV) beams, the responses of the crystal chamber are evaluated against a PTW Farmer-type chamber at a field size of 10${\times}$10cm$^2$ and 100 cm SSD. The responses of crystal chamber for therapeutic radiation electron and photon beams are greater in magnitude by several order than Farmer. The crystal chamber has good linearity without correction factor C$\_$t,p/ with respect to the signals, a reading reproduction with good accuracy and precision less than 0.5%, and has other useful functions in measuring radiation beams.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1081-1091
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• 2012

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal hematologic neoplasms characterized by morphologic dysplasia, aberrant hematopoiesis and peripheral blood refractory cytopenias. MDS is recognized to be associated with an increased risk of symptomatic anemia, infectious complications and bleeding diathesis, as well as a risk of progression to acute myeloid leukemia, particularly in patients with a high IPSS score. The advent of use of hematopoietic growth factors such as granulocyte colony-stimulating factor (G-CSF) and recombinant erythropoietin (EPO) has improved symptoms in MDS patients in addition to some data that suggest there might be an improvement in survival. G-CSF is an effective therapeutic option in MDS patients, and it should be considered for the management of refractory symptomatic cytopenias. G-CSF and EPO in combination can improve outcomes in appropriate MDS patients such as those with lower-risk MDS and refractory anemia with ring sideroblasts (RARS). This article reviews use of growth factors for lower-risk MDS patients, and examines the data for G-CSF, EPO and thrombopietic growth factors (TPO) that are available or being developed as therapeutic modalities for this challenging disease.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.5 s.347
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• pp.48-53
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• 2006

This paper describes the electrical characteristics of monolithic optical transceiver circuitry being used in the fiber optic modules. It has been designed and fabricated, and compared with two chips version transceiver when operates at 155.52 Mbps data rates. To avoid noise and interference between transmitter and receiver on one chip, layout techniques such as special placement, power supply separation, guard ring, and protection wall were used in the design. To compare the two kind of fiber optic modules using each chip, single chip version has similar properties to two chip version in the electrical characteristics as noise and others.

• Journal of Semiconductor Engineering
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• v.3 no.2
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• pp.161-167
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• 2022

Electrical characteristics of LDMOS power device with LDD(Lightly Doped Drain) structure is studied with variation of the region of channel and LDD. The channel in LDMOSFET encloses a junction-type source and is believed to be an important parameter for determining the circuit operation of CMOS inverter. Two-dimensional TCAD MEDICI simulation is used to study hot-carrier effect, on-resistance Ron, breakdown voltage, and transient switching characteristic. The voltage-transfer characteristics and on-off switching properties are studied as a function of the channel length and doping levels. The digital logic levels of the output and input voltages are analyzed from the transfer curves and circuit operation. Study indicates that drain current significantly depends on the channel length rather than the LDD region, while the switching transient time is almost independent of the channel length. The high and low logic levels of the input voltage showed a strong dependency on the channel length, while the lateral substrate resistance from a latch-up path in the CMOS inverter was comparable to that of a typical CMOS inverter with a guard ring.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.2
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• pp.1-8
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• 2004

This paper describes the design of monolithic optical transceiver circuitry being used as a part of the fiber optic modules. It has been designed in 0.6 ${\mu}{\textrm}{m}$ 2-poly 3 metal silicon CMOS analog technology and operates at 155.52 Mbps(STM-1) data rates. It drives laser diode to transmit intensity modulated optical signal according to 155.52 Mbps electrical data from system. Also, it receives 155.52 Mbps optical data that transmitted from other systems and converts it to electrical data using photo diode and amplifier. To avoid noise and interference between transmitter and receiver on one chip, layout techniques such as special placement, power supply separation, guard ring, and protection wall were used in the design. The die area is 4 ${\times}$ 4 $\textrm{mm}^2$ and the estimated power dissipation is less than 900 ㎽ with a single 5 V supply.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.9
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• pp.11-17
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• 2004

This paper describes the implementation of monolithic optical transceiver circuitry being used as a part of the fiber optic modules. It has been fabricated in 0.6 ${\mu}{\textrm}{m}$ 2-poly 3-metal silicon CMOS analog technology and operates at 155.52 Mbps(STM-1) data rates. It drives laser diode to transmit intensity modulated optical signal according to 155.52 Mbps electrical data from system. Also, it receives 155.52 Mbps optical data that transmitted from other systems and converts it to electrical data using photo diode and amplifier. To avoid noise and interference between transmitter and receiver on one chip, layout techniques such as special placement, power supply separation, guard ring, and protection wall were used in the design. The die area is 4 ${\times}$ 4 $\textrm{mm}^2$, and it has 32.3 ps rms and 335.9 ps peak to peak jitter on loopback testing. the measured power dissipation of whole chip is 1.15 W(230 mW) with a single 5 V supply.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.12
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• pp.49-57
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• 2001

In this paper, equivalent circuit model and novel model parameter extraction method of a silicon(Si) substrate are presented. Substrate coupling through Si-substrate is quantitatively investigated by analyzing equivalent circuit with operating frequency and characteristic frequencies (i.e., pole and zero frequency) of a system. For the experimental verification of the equivalent circuit and parameter extraction method, test patterns are designed and fabricated in standard CMOS technology with various isolation distances, substrate resistivity, and guard-ring structures. Then, these are measured in l00MHz-20GHz frequency range by using vector network analyzer. It is shown that the equivalent-circuit-based HSPICE simulation results using extracted parameters have excellent agreement with the experimental results. Thus, the proposed equivalent circuit and parameter extraction methodology can be usefully employed in mixed-signal circuit design and verification of a circuit performance.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.1 s.24
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• pp.47-52
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• 2006

Recently, ship collision accidents account for $20%{\sim}34%$ of domestic marine accidents, also have increased continually. In this paper, therefore we propose the development of Ship Collision A voidance Support program for decreasing ship collision accidents. This program has been developed on the basis of CCAS-Model. A CCAS-Model has ship's maneuvering performance and has been studied for the propose of supporting to avoid ship collision in close quarters. Besides. the program will effectively support maneuvering for collision avoidance through display of the feasible area and the method of collision avoidance using own ship's turning characteristic about action of target ship's keeping course and velocity in various encounter.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.3
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• pp.143-150
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• 2009

Fuel oil mostly used for a ship is made from crude oil by refining process. In order to produce plenty of high-quality fuel oil, the Fluid catalytic cracking(FCC) method is widely adopted to many refinery factories during the decomposition process from high molecule into lower molecule. The major constituents in spent FCC catalysts are Si, Al, Fe, Ti, alkali metals and some others. The spent catalyst is also composed small amounts of rare metals such as Ce, Nd, Ni and V. The big problem in FCC oil is mixing the catalyst in the oil. This reason is unstable separation of FCC catalyst in separator. Such a FCC catalyst will become a reason of heavy wear down in moving parts of engine. The impurity in oil is ash and deposit compound, such as Al, Si, Ni, Fe and V, which will accelerate the wear down on fuel pump, fuel injection valve cylinder liner and piston ring. It is important to find a basic reason of an engine trouble for preventing similar troubles anymore. Insurance compensation will be different according to the reason of an engine trouble which might be natural abrasion or other external causes. In this study, types and reasons of engine troubles related to fuel oil will be covered.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.11
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• pp.83-94
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• 2003

In this paper. a highly linear and low glitch CMOS current mode digital-to-analog converter (DAC) by self calibration bias circuit is proposed. The architecture of the DAC is based on a current steering 6＋4 segmented type and new switching scheme for the current cell matrix, which reduced non-linearity error and graded error. In order to achieve a high performance DAC . novel current cell with a low spurious deglitching circuit and a new inverse thermometer decoder are proposed. The prototype DAC was implemented in a 0.35${\mu}{\textrm}{m}$ n-well CMOS technology. Experimental result show that SFDR is 60 ㏈ when sampling frequency is 32MHz and DAC output frequency is 7.92MHz. The DAC dissipates 46 mW at a 3.3 Volt single power supply and occupies a chip area of 1350${\mu}{\textrm}{m}$ ${\times}$750${\mu}{\textrm}{m}$.