• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.1 no.1
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• pp.56-78
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• 1998

Objective: Chronic hepatitis B infection (CHB) occurs in 6% to 10% of population in Korea. In ethinic communities where prevalence of chronic infection is high such as Korea, transmission of hepatitis B infection is either vertical (ie, by perinatal infection) or by close family contact (usually from mothers or siblings) during the first 5 years of life. The development of chronic hepatitis B infection is increasingly more common the earlier a person is exposed to the virus, particularly in fetal and neonatal life. And it progress to cirrhosis and hepatocellular carcinoma, especially in severe liver damage and perinatal infection. Histopathology of CHB is important when evaluating the final outcomes. A numerical scoring system which is a semiquantitatively assessed objective reproducible classification of chronic viral hepatitis, is a valuable tool for statistical analysis when predicting the outcome and evaluating antiviral and other therapies. In this study, a numerical scoring system (Ludwig system) was applied and compared with the conventional histological classification of De Groute. And the comparative analysis of cinical findings, family history, serology, and liver function test by histopathological findings in chronic hepatitis B of children was done. Methods: Ninety nine patients [mean age=9 years (range=17 months to 16 years)] with clinical, biochemical, serological and histological patterns of chronic HBV infection included in this study. Five of these children had hepatocelluar carcinoma. They were 83 male and 16 female children. They all underwent liver biopsies and histologic evaluation was performed by one pathologist. The biopsy specimens were classified, according to the standard criteria of De Groute as follows: normal, chronic lobular hepatitis (CLH), chronic persistent hepatitis (CPH), mild to severe chronic active hepatitis (CAH), or active cirrhosis, inactive cirrhosis, hepatocellular carcinoma (HCC). And the biopsy specimens were also assessed and scored semiquantitatively by the numerical scoring Ludwig system. Serum HBsAg, anti-HBs, HBeAg, anti-HBe, anti-HBc (IgG, IgM), and HDV were measured by radioimunoassays. Results: Male predominated in a proportion of 5.2:1 for all patients. Of 99 patients, 2 cases had normal, 2 cases had CLH, 22 cases had CPH, 40 cases had mild CAH, 19 cases had moderate CAH, 1 case had severe CAH, 7 cases had active cirrhosis, 1 case had inactive cirrhosis, and 5 cases had HCC. The mean age, sex distribution, symptoms, signs, and family history did not differ statistically among the different histologic groups. The numerical scoring system was correlated well with the conventional histological classification. The histological activity evaluated by both the conventional classification and the scoring system was more severe as the levels of serum aminotransferases were higher. In contrast, the levels of serum aminotransferases were not useful for predicting the degree of histologic activity because of its wide range overlapping. When the histological activity was more severe and especially the cirrhosis more progressing, the prothrombin time was more prolonged. The histological severity was inversely related with the duration of seroconversion of HBeAg. Conclusions: The histological activity could not be accurately predicted by clinical and biochemical findings, but by the proper histological classification of the numerical scoring system for the biopsy specimen. The numerical scoring system was correlated well with the conventional histological classification, and it seems to be a valuable tool for the statistical analysis when predicting the outcome and evaluating effects of antiviral and other therapies in chronic hepatitis B in children.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.53-65
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• 2001

Purpose : To improve the local control of patients with nasopharyngeal cancer, we have implemented 3-D conformal radiotherapy and forward intensity modulated radiation therapy (IMRT) to used of compensating filters. Three dimension conformal radiotherapy with intensity modulation is a new modality for cancer treatments. We designed 3-D treatment planning with 3-D RTP (radiation treatment planning system) and evaluation dose distribution with tumor control probability (TCP) and normal tissue complication probability (NTCP). Material and Methods : We have developed a treatment plan consisting four intensity modulated photon fields that are delivered through the compensating tilters and block transmission for critical organs. We get a full size CT imaging including head and neck as 3 mm slices, and delineating PTV (planning target volume) and surrounding critical organs, and reconstructed 3D imaging on the computer windows. In the planning stage, the planner specifies the number of beams and their directions including non-coplanar, and the prescribed doses for the target volume and the permissible dose of normal organs and the overlap regions. We designed compensating filter according to tissue deficit and PTV volume shape also dose weighting for each field to obtain adequate dose distribution, and shielding blocks weighting for transmission. Therapeutic gains were evaluated by numerical equation of tumor control probability and normal tissue complication probability. The TCP and NTCP by DVH (dose volume histogram) were compared with the 3-D conformal radiotherapy and forward intensity modulated conformal radiotherapy by compensator and blocks weighting. Optimization for the weight distribution was peformed iteration with initial guess weight or the even weight distribution. The TCP and NTCP by DVH were compared with the 3-D conformal radiotherapy and intensitiy modulated conformal radiotherapy by compensator and blocks weighting. Results : Using a four field IMRT plan, we have customized dose distribution to conform and deliver sufficient dose to the PTV. In addition, in the overlap regions between the PTV and the normal organs (spinal cord, salivary grand, pituitary, optic nerves), the dose is kept within the tolerance of the respective organs. We evaluated to obtain sufficient TCP value and acceptable NTCP using compensating filters. Quality assurance checks show acceptable agreement between the planned and the implemented MLC(multi-leaf collimator). Conclusion : IMRT provides a powerful and efficient solution for complex planning problems where the surrounding normal tissues place severe constraints on the prescription dose. The intensity modulated fields can be efficaciously and accurately delivered using compensating filters.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.6
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• pp.1210-1230
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• 1997

In this paper, we suggest an architecture of DS/CDMA tranceiver composed of one pilot channel used as reference and multiple traffic channels. The pilot channel-an unmodulated PN code-is used as the reference signal for synchronization of PN code and data demondulation. The coherent demodulation architecture is also exploited for the reverse link as well as for the forward link. Here are the characteristics of the suggested DS/CDMA system. First, we suggest an interlaced quadrature spreading(IQS) method. In this method, the PN coe for I-phase 1st channel is used for Q-phase 2nd channels and the PN code for Q-phase 1st channel is used for I-phase 2nd channel, and so on-which is quite different from the eisting spreading schemes of DS/CDMA systems, such as IS-95 digital CDMA cellular or W-CDMA for PCS. By doing IQS spreading, we can drastically reduce the zero crossing rate of the RF signals. Second, we introduce an adaptive threshold setting for the synchronization of PN code, an initial acquistion method that uses a single PN code generator and reduces the acquistion time by a half compared the existing ones, and exploit the state machines to reduce the reacquistion time Third, various kinds of functions, such as automatic frequency control(AFC), automatic level control(ALC), bit-error-rate(BER) estimator, and spectral shaping for reducing the adjacent channel interference, are introduced to improve the system performance. Fourth, we designed and implemented the DS/CDMA MODEM to be used for variable transmission rate applications-from 16Kbps to 1.024Mbps. We developed and confirmed the DS/CDMA MODEM architecture through mathematical analysis and various kind of simulations. The ASIC design was done using VHDL coding and synthesis. To cope with several different kinds of applications, we developed transmitter and receiver ASICs separately. While a single transmitter or receiver ASC contains three channels (one for the pilot and the others for the traffic channels), by combining several transmitter ASICs, we can expand the number of channels up to 64. The ASICs are now under use for implementing a line-of-sight (LOS) radio equipment.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.88-94
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• 2014

Among pre-harvest environmental factors, increasing attention has been paid to the effects of chemical and microbiological factors on fresh produce. The occurrence and prevalence of these factors have been usually studied with regard to the final products at the post-harvesting stage and/or when they are sold in the market. However, the origin and routes of transmission of both factors remain to be clarified. In the present study, we examined the contamination levels of food-borne pathogens and chemical factors such as pesticide residues and heavy metals in 83 and 43 samples, respectively, including various soil, water, and fertilizer samples, as well as post-harvested and processed samples. Among the organic farming samples, only one pesticide, dimethomorph, was detected in the soil sample, however no pesticides were observed from any other samples in organic farming system. Thus, it was thought that might be contaminated from conventional farm land in the vicinity. Whereas many pesticide residues were detected in conventional farming systems such as soil, fertilizer, water, and fresh produce as expected. Furthermore, heavy metals detected from all tested samples did not shown contamination levels higher than the standard limit. We comparatively assessed the levels of contamination by food-borne pathogens on the samples from organic and conventional farming systems, and found aerobic bacteria at approximately 7 log CFU/g, with no significant differences observed between the two systems. Coliforms were present at lower levels than aerobic bacteria. No human pathogens were present among the coliforms detected, indicating that these bacteria are saprophytes without the ability to cause food-borne illnesses. In contrast, among the high-risk food-borne pathogens, only sporadic cells of Bacillus cereus were found on samples of organic farming system. These data extend previous findings that the most prevalent food-borne pathogen is B. cereus and demonstrate that it spreads to whole living plants via soil.

• The korean journal of orthodontics
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• v.29 no.1 s.72
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• pp.73-81
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• 1999

Midpalatal suture expansion is often used for patients haying narrow maxillary arch, cleft palate, respiratory handicap with narrow nasal cavity. CGRP has been known as a modulator of pain transmission in central nervous system and a local effector to peripheral tissue causing vasodilation, increase of blood flow, modulation of immune system, regulation of macrophagic function and stimulation of bone formation. To investigate changes of CGRP-immunoreactive nerve fibers in midpalatal suture during the expansion, immunohistochemical study was performed by using rats. Experimental rats (10 weeks, 250 gm) were divided into five groups (control, 1, 4, 7, 14 days group (each n=4) and applied orthodontic force (approximately 200gm) to upper anterior incisors. Frozen sections of midpalatal suture area were immunostained by using rabbit antisera. The results were as follows. ${\cdot}$ The CGRP-immunoreactive nerve fibers were hardly observed in control group. ${\cdot}$ In 1 day group, the CGRP-immunoreactive nerve fibers were more increased around the vessels than control group. ${\cdot}$ In 4 days group, the CGRP-immunoreactive nerve fibers were more increased than control group, but not more increased than 1 day group. Vascular diameter was more enlarged. ${\cdot}$ In 7 days group, especially, hematoxilin affinity of cells was remarkable and cells were arranged along the bone margin. The CGRP-immunoreactive nerve fibers were more reduced than 4 days group and vascular diameter was also reduced. ${\cdot}$ In 14 days group, the CGRP-immunoreactive nerve fibers were similar to those of 7 days group and the irregularity of bone margin was almost recoverd. In Conclusion, the CGRP-immunoreactive nerve fibers nay be related to initial neurogenic inflammatory reaction in expanding mid-palatal suture.

• Journal of Life Science
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• v.30 no.8
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• pp.701-707
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• 2020

Gene editing technology using the clustered regularly interspaced short palindromic repeat (CRISPR) and the CRISPR associated protein (Cas)9 has been highly anticipated in developing breeding techniques. In this study, we discuss gene scissors as a tool for silkworm molecular breeding through analysis of Bombyx mori Kynurenine 3-Monooxygenase (BmKMO) gene editing using the CRISPR/Cas9 system and analysis of generational transmission through mutagenesis and selective crossing. The nucleotide sequence of the BmKMO gene was analyzed, and three guide RNAs (gRNAs) were prepared. Each synthesized gRNA was combined with Cas9 protein and then analyzed by T7 endonuclease I after introduction into the BM-N silkworm cell line. To edit the silkworm gene, K1P gRNA and Cas9 complexes were subsequently microinjected into the silkworm embryos; the hatching rate was 18% and the incidence of mutation was 60%. The gene mutation was verified in the heterozygous G0 generation, but no phenotypic change was observed. In homozygotes generated by self-crossing, a mutant phenotype was observed. These results suggest that silkworm molecular breeding using the CRISPR/Cas9 system is possible and could be an effective way of shortening the time required.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.9
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• pp.14-23
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• 2010

This paper reports the fabrication of a DVB-T/H System in Package (SiP) that is able to receive and process the DVB-T/H signal. The DVB-T/H is the European telecommunication standard for Digital Video Broadcasting (DVB). An IC-embedded Printed Circuit Board (PCB) process, interpose a chip between PCB layers, has applied to the DVB-T/H SiP. The chip inserted in DVB-T/H SiP is the System on Chip (SoC) for mobile TV. It is comprised of a RF block for DVB-T/H RF signal and a digital block to convert received signal to digital signal for an application processor. To operate the DVB-T/H IC, a 3MHz DC-DC converter and LDO are on the DVB-T/H SiP. And a 38.4MHz crystal is used as a clock source. The fabricated DVB-T/H SiP form 4 layers which size is $8mm{\times}8mm$. The DVB-T/H IC is located between 2nd and 3rd layer. According to the result of simulation, the RF signal sensitivity is improved since the layout modification of the ground plane and via. And we confirmed the adjustment of LC value on power transmission is necessary to turn down the noise level in a SiP. Although the size of a DVB-T/H SiP is decreased over 70% than reference module, the power consumption and efficiency is on a par with reference module. The average power consumption is 297mW and the efficiency is 87%. But, the RF signal sensitivity is declined by average 3.8dB. This is caused by the decrease of the RF signal sensitivity which is 2.8dB, because of the noise from the DC-DC converter.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.6
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• pp.356-370
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• 2017

The energy savings and $CO_2$ emission reductions obtainable from the situation that the Smart Grid system (SGs) is assumed to be applied in Korea up to 2030 is quantitatively analyzed with many reported data. For calculation, SGs is divided into five sectors such as Smart Transmission and Distribution (ST&D), Smart Consumer (SC), Smart Electricity Service (SES), Smart Renewable Energy (SRE) and Smart Transportation (ST). Total annual energy savings in 2030 is estimated to be approximately 103,121 GWh and this is 13.1% of total electricity consumption outlook. Based on this value, total amount of reducible $CO_2$ emissions is calculated to 55.38 million $tCO_2$, which is 17.6% of total nation's GHG reduction target. Although the contribution of energy saving due to SGs to total electricity consumption increases as years go by, that of $CO_2$ emission reduction gradually decreases. This might be because that coal fired based power generation is planned to be sharply increased and the rate of $CO_2$ emission reduction scheduled by nation is very fast. The contributable portion of five each sector to total $CO_2$ emission reductions in 2030 is estimated to be 44.37% for SC, 29.16% for SRE, 20.12% for SES, 5.11% for ST&D, and 1.24% for ST.

• Korean Security Journal
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• no.21
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• pp.155-175
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• 2009

RFID that provide automatic identification by reading a tag attached to material through radio frequency without direct touch has some specification, such as rapid identification, long distance identification and penetration, so it is being used for distribution, transportation and safety by using the frequency of 125KHz, 134KHz, 13.56MHz, 433.92MHz, 900MHz, and 2.45GHz. Also it is one of main part of Ubiquitous that means connecting to net-work any time and any place they want. RFID is expected to be new growth industry worldwide, so Korean government think it as prospective field and promote research project and exhibition business program to linked with industry effectively. RFID could be used for access control of person and vehicle according to section and for personal certify with password. RFID can provide more confident security than magnetic card, so it could be used to prevent forgery of register card, passport and the others. Active RFID could be used for protecting operation service using it's long distance date transmission by application with positioning system. And RFID's identification and tracking function can provide effective visitor management through visitor's register, personal identification, position check and can control visitor's movement in the secure area without their approval. Also RFID can make possible of the efficient management and prevention of loss of carrying equipments and others. RFID could be applied to copying machine to manager and control it's user, copying quantity and It could provide some function such as observation of copy content, access control of user. RFID tag adhered to small storage device prevent carrying out of item using the position tracking function and control carrying-in and carrying-out of material efficiently. magnetic card and smart card have been doing good job in identification and control of person, but RFID can do above functions. RFID is very useful device but we should consider the prevention of privacy during its application.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.71-73
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• 2000

Campylobacter jejuni is most frequently identified cause of cause of acute diarrhoeal infections in developeed countries, exceeding rates of illness caused by both salmonella and shigilla(Skirrow, 1990 ; Lior 1994). Previous studies on campylobacter jejuni contamination of commercial broiler carcasses in u.s.(Stern, 1992). Most cases of the disease result from indirect transmission of Campylobactor from animals via milk, water and meat. In addition to Campylobactor jejuni. the closely relates species Campylobactor coli and Campylobactor lari have also been implicated as agents of gastroenteritis in humans. Campylobactor coli represented only approximately 3% of the Campylobactor isolates from patients with Campylobactor enteritis(Griffiths and Park, 1990) whereas Campylobactor coli is mainly isolated from pork(Lmmerding et al., 1988). Campylobactor jejuni has also been isolated from cases of bacteremia, appendicitis and, recently, has been associated with Guillai-Barre syndrome(Allos and Blaser, 1994; von Wulffen et al., 1994; Phillips, 1995). Studies in volunteers indicated that the infectious dose for Campylobactor jejuni is low(about 500 organisms)(Robinson, 1981). The methods traditionally used to detect Campylobactor ssp. in food require at least two days of incubation in an enrichment broth followed by plating and two days of incubation on complex culture media containing many antibiotics(Goossens and Butzler, 1992). Finnaly, several biochemical tests must be done to confirm the indentification at the species level. Therfore, sensitive and specific methods for the detection of small numbers of Campylobactor cells in food are needed. Polymerase chain reaction(PCR) assays targeting specific DNA sequences have been developed for the detection of Campylobactor(Giesendorf and Quint, 1995; Hemandex et al., 1995; Winter and Slavidk, 1995). In most cases, a short enrichment step is needed to enhance the sensitivity of the assay prior to detection by PCR as the number of bacteria in the food products is low in comparison with those found in dinical samples, and because the complex composition of food matrices can hinder the PCR and lower its sensitivity. However, these PCR systems are technically demanding to carry out and cumbersome when processing a large number of samples simutaneously. In this paper, an immunomagnetic method to concentrate Campylobactor cells present in food or clinical samples after an enrichment step is described. To detect specifically the thermophilic Campylobactor. a monoclonal antibody was adsorbed on the surface of the magnetic beads which react against a major porin of 45kDa present on the surface of the cells(Huyer et al., 1986). After this partial purification and concentration step, detection of bound cells was achieved using a simple, inexpensive microtitre plate-based hybridization system. We examined two alternative detection systems, one specific for thermophilic Campylobactor based on the detection of 23S rRNA using an immobilized DNA probe. The second system is less specific but more sensitive because of the high copy number of the rRNA present in bacterial cell($10^3-10^4$). By using specific immunomagnetic beads against thermophilic Campylobactor, it was possible to concentrate these cells from a heterogeneous media and obtain highly specific hybridization reactions with good sensitivity. There are several advantages in using microtitre plates instead of filter membranes or other matrices for hybridization techniques. Microtitre plates are much easier to handle than filter membranes during the adsorption, washing, hybridization and detection steps, and their use faciilitates the simultanuous analysis of multiple sample. Here we report on the use of a very simple detection procedure based on a monoclonal anti-RNA-DNA hybrid antibody(Fliss et al., 1999) for detection of the RNA-DNA hybrids formed in the wells.