• Radiation Oncology Journal
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• v.11 no.2
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• pp.267-275
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• 1993

Eighty five patients of oral cavity cancer, treated with radiation at the Department of Therapeutic Radiology, Korea Cancer Center Hospital, during the period from March 1985 to September 1990 were analyzed retrospectively. Among 85 patients, 37 patients were treated with radiation only and 48 patients were treated with radiation following surgery. And 70 patients received external irradiation only by $^{60}Co$ with or without electron, the others were 7 patients for external irradiation plus interstitial implantation and 8 patients for external irradiation plus oral cone electron therapy. Primary sites were mobile tongue for 40 patients, mouth floor for 17 patients, palate for 12 patients, gingiva including retromolar trigone for 10 patients, buccal mucosa for 5 patients, and lip for 1 patient. According to pathologic classification, squamous cell carcinoma was the most common (77 patients). According to AJC TNM stage, stage I + II were 28 patients and stage III+IV were 57 patients. Acturial overall survival rate at 3 years was $43.9\%,$ 3 year survival rates were $60.9\%$ for stage I + II, and $23.1\%$ for stage III+IV, respectively. As a prognostic factor, primary T stage was a significant factor (p<0.01). The others, age, location, lymph node metastasis, surgery, radiation dose, and cell differentiation were not statistically significant. Among those factors, radiation plus surgery was more effective than radiation only in T3+T4 or in any N stage although it was not statistically sufficient (p<0.1). From those results, it was conclusive that definitive radiotherapy was more effective than surgery especially In the view of pertainig of anatomical integrity and function in early stage, and radiation plus surgery was considered to be better therapeutic tool in advanced stage.

• Journal of Advanced Navigation Technology
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• v.6 no.3
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• pp.195-202
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• 2002

Recently, as the range of mobile communication services is extended, the interference between adjacent base-stations is increased. Nowdays, one of the important factors causing interference is IMD (Inter-Modulation Distortion) problems. Not only active IMD but also passive IMD effects must be considered to design a CDMA system. In this study, we design and implement 7/16" DIN connectors which have a various intensity of surface illumination, thickness and quality of plating material to analyze the effects of PIMD. And propose the methods for improving the PIMD characteristics: First, it is more profitable to use the metal which has good intensity of surface illumination where most of all electric currents passes through it. Secondly, we should plate metals more than $5{\mu}m$ for RF energy enough to propagate in a medium. Thirdly, it is necessary to select a metal having high conductivity and specific heat to protect the aging phenomenon of plate material. And it is required to develop a new plating material to replace the current materials, such as the alloy of three components for cost reduction. We have to know that the plate which has intensity of surface illumination 6 S and the thickness of plating material $5{\mu}m$ satisfy the domestic PIMD specification (KTF) -150 dBc, regardless of the plate material in case of 7/16" DIN connector.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.744-753
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• 2015

This paper presents the results of research on developing marine unified communications to provide VoIP service based on marine satellites. With the recent popularity of smart-phones and other mobile devices, the demand for Internet-based wired and wireless unified technology has been growing in marine environments, and increasing interest is being directed to VoIP products and service models with high price competitiveness and the ability to deliver a variety of services. In this regard, this research designed three instruments, developed their unit modules, and verified their performances. These three instruments included the following: (1) a marine VoIP module equipped with an analogue gateway that can be linked to the existing devices used in vessels, which is more than 80% smaller than that of a land system; (2) a text/voice/video engine for marine satellite communications that runs on technology that minimizes communication data usage, which is a core technology for a marine VoIP service; and (3) a unified communication service that can support multilateral cloud-based message conversations, telephone number-based call functions, and voice/video calling between a private space in a ship and shore.

• Food Science and Preservation
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• v.24 no.6
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• pp.795-801
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• 2017

Aralia elata Seemann (AE) has long been used as a folk medicine for the treatment of various diseases including diabetes mellitus, anti-arthritic, and anti-gastric ulcer agent in Korea, Japan, and China. This study was performed to establish a simple and reliable HPLC/UV analytical method for determination of most active anti-hypertensive compound, a 3-O-${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}$2)-${\alpha}$-L-arabinopyranosyl hederagenin 28-O-${\beta}$-D-xylopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranosylester (HE) for the standardization of the shoot extract of AE as a health functional food ingredient. The quantitative analytical method of HE was optimized by HPLC analysis using reverse-phase C18 column at $40^{\circ}C$ with $H_2O$ and acetonitrile (70:30, v/v) as an isocratic mobile phase at a flow rate of 1.0 mL/min and detection wavelength of UV 205 nm. This HPLC/UV analytical method showed good specificity and high linearity in the tested range of 0.03125-2.0mg/ml with excellent coefficient of determination ($R^2$) of 0.9999. The limit of detection and limit of quantification were $12.0{\mu}g/mL$ and $36.5{\mu}g/mL$, respectively. Relative standard deviation (RSD) values of data from intra- and inter-day precision were less than 0.2% and 0.1%, respectively. These results indicate that the established HPLC/UV analytical method is very simple, specific, precise, accurate, and reproducible and thus can be useful for the quantitative analysis of HE as a functional anti-hypertensive compound in AE extract.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.135-143
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• 2009

Integrating the Global Positioning System (GPS) and Inertial Navigation System (INS) sensor technologies using the precise GPS Carrier phase measurements is a methodology that has been widely applied in those application fields requiring accurate and reliable positioning and attitude determination; ranging from 'kinematic geodesy', to mobile mapping and imaging, to precise navigation. However, such integrated system may not fulfil the demanding performance requirements when the baseline length between reference and mobil user GPS receiver is grater than a few tens of kilometers. This is because their positioning/attitude determination is still very dependent on the errors of the GPS observations, so-called "baseline dependent errors". This limitation can be remedied by the integration of GPS and INS sensors, using multiple reference stations. Hence, in order to derive the GPS distance dependent errors, this research proposes measurement processing algorithms for multiple reference stations, such as a reference station ambiguity resolution procedure using linear combination techniques, a error estimation based on Kalman filter and a error interpolation. In addition, all the algorithms are evaluated by processing real observations and results are summarized in this paper.

• Proceedings of the Korean DIstribution Association Conference
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• 2001.11b
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• pp.125-141
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• 2001

In this paper, the current problems of logistics industry in Korea and their possible solutions were discussed. With Korea Telecoms KT-Logis, the supplier and demander of logistics service would not have to invest large sum of money into their computer system. All they need is just a computer with internet connected. What KT-Logis influence on the logistics industry are the following; 1. Many logistics service supplier and demander can do the business on the web with one computer system. 2. This web based computer system does not only work on the office but also apply on the field worker such as delivery personnel or even the forwarder with mobile phone. 3. KT-Logis is an integrated system which cover the broad arrange of logistics management from truck management to customer relations management. 4. Finally, KT-Logis is web based systems which suits for current e-business and mobile environment. In future, more studies should be done to develop more progressive integrated logistics information systems with enterprise resource planning(ERP) and supply chain management(SCM).

• YAKHAK HOEJI
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• v.51 no.2
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• pp.133-139
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• 2007

A simple and sensitive HPLC-MS method for quantitation of 10${\alpha}$-methoxy-9,10-dihydrolysergol (MDL), the main metabolite of nicergoline, in human plasma was developed and the bioavailability parameters of MDL was assessed in Korean healthy male volunteers. Clomipramine was used as an internal standard. MDL and internal standard in plasma sample were extracted using ethyl acetate. A centrifuged upper layer was then evaporated and reconstituted with mobile phase of 10 mM ammonium acetate-acetonitrile (10 : 90, v/v). The reconstituted samples were injected into a Zorbax SB-C8 column (2.1${\times}$150 mm,5 ${\mu}$m) at a flow-rate of 0.3 ml/min. Using MS with selected ion monitoring (SIM) mode, MDL and clomipramine were detected without severe interference from human plasma matrix. MDL produced a protonated molecular ion ([M+H]$^+$) at m/z 287. Internal standard produced a protonated molecular ion ([M+H]$^+$) at m/z 315. A linear relationship for MDL was found in the range of 2.5${\sim}$100 ng/ml. The lower limit of quantitation (LLOQ) was 2.5 ng/ml with acceptable precision and accuracy. The intra- and inter-day validation for all coefficients of variation (R.S.D.%) were found less than 15%. Main pharmacokinetic parameters of 30 mg of nicergoline were revealed as follows: AUC$_t$ 321.1${\pm}$64.5 ng${\cdot}$hr/ml, C$_{max}$, 51.2${\pm}$25.3 ng/ml, T$_{max}$ 3.6${\pm}$1.5 hr, K$_{el}$ 0.12${\pm}$0.07 hr$^{-1}$ and t$_{1/2}$ 7.6${\pm}$3.4 hr. Inter subject variations and race differences were shown in comparison with the published data in the literature.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.3
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• pp.276-282
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• 2022

Close communication between clinicians and dental technicians is an important factor in providing successful prostheses. The exchange of opinions with laboratories has mainly been in the form of written prescriptions and a photos, but it has been reported that information transmission may be limited. Currently, as digital technology-based prosthesis fabrication is common, 3D image objects can be stored on the web and can be easily viewed through a mobile web browser. In this article, we introduce cases where the design of the prosthesis was improved by designing the prosthesis using CAD software and reviewing the prosthesis designed with the clinical side through a web viewer. Through this protocol, it was possible to improve the occlusal surface and crown contour, the opposing teeth condition, the size of the gingival embrasure, and the shape of pontic. The process of sharing, discussing, and modifying the prosthesis design with the clinician and technician through a web viewer contributes to reflecting the diversity of oral conditions and individualized needs, thereby helping to make functional and esthetic prostheses.

• Journal of Food Hygiene and Safety
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• v.19 no.1
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• pp.12-18
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• 2004

Ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin in chicken muscle were seperated by liquid extraction and determined with high performance liquid chromatography (HPLC) with fluorescence detector. Analysis was carried out using following conditions; Cl8 column (250${\times}$4.6 mm i.d. 5 ${\mu}{\textrm}{m}$ particle size), mobile phase composed of D.W. (containing 0.4% triethylamine and phospholic acid): methanol : acetonitrile (800:100:100, v/v/v), isocratic pump at a flow rate of 1.0 $m\ell$/min and 50 ${mu}ell$ of injection volume, fluorescence detector with EX278 nm/EM.456 nm. The calibration curves of four fluoroquinolones showed linearity (${\gamma}$$^2$$\geq$0.999) at concenration range of 0.025-0.6 $\mu\textrm{g}$/ml. The recoveries in fortified chicken muscle represented more than 80% with low coefficient of variation (〈10%) for concentration range of four fluoroquinolones. The detection limits for ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin were 23.5, 3.4, 3.0 and 2.5 ng/g in chicken muscle, respectively. We also monitored fluoroquinolones residue in muscle of chickens (broiler 1:227, Korean native chicken 219, laying chicken 77) using EEC-4-plate screening and HPLC conformation methods. Ten(broiler 5, Korean native chicken 5) out of the fifteen samples which were positively detected by EEC-plate screening method from 1,523 chicken meat were confirmed with ciprofloxacin and enrofloxacin by HPLC. The ranges of residual concentration were 0-0.12 ppm for ciprofloxacin and 0.01-6.79 ppm for enrofloxacin. In conclusion, our method could be applied effectively to determine four fluoroquinolones residues in chicken meat, and further survey for fluoroquinolones residue in chicken meat are needed for more effective control of fluoroquinolones used in livestock.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.166-174
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• 2016

BACKGROUND: The current study developed a monitoring method of 6 veterinary antibiotics (amoxicillin, ampicillin, enrofloxacin, tetracycline, chlortetracycline, oxytetracycline) in agricultural soils using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization mode.METHODS AND RESULTS: Sample preparation was carried out using acidic acetonitrile and citrate salts followed by purification with dispersive solid phase extraction (d-SPE). Separation on Eclipse Plus C₁₈ column was conducted in gradient of the mobile phase, 0.1% formic acid and 5 mM ammonium formate in methanol (A) and 0.1% formic acid and 5 mM ammonium formate in distilled water (B). The linearity of the matrix-matched calibrations expressed as the coefficient of determination was good with R²≥0.9900. The limit of quantifications (LOQs) ranged from 0.5 to 10 μg/kg for all analytes. Analysis of 51 agricultural soil samples taken in the Republic of Korea revealed concentrations less than 1.9 μg/kg for enrofloxacin, 75.5 μg/kg for chlortetracycline.CONCLUSION: The method was successfully applied to monitor 6 veterinary antibiotics from 51 field incurred agricultural soil samples in 17 provincial areas throughout the Republic of Korea. The developed method was simple, easy, and versatile and can be used for monitoring various veterinary antibiotics in soil.