순환전압전류법을 이용한 fenofibrate 분석

김유정,윤영자 崇實大學校 生産技術硏究所 2002 論文集 Vol.32 No.-

A determination method of trace fenofibrate, called one of the medical treatment of hyperlipidemia, has been studied by Cyclic Voltammetry. The optimum condition of fenofibrate analysis, were as follows; supporting electrolyte was adjusted by 0.1M phosphoric acid pH 1.55. Deposition potential was -0.25 V.(vs. Ag/AgCl reference electrode) and deposition time was 150 s under constant stirring. Equilibrium time was 25 sec and scan rate 100 mV/sec.

전침 자극에 의한 오디 괄약근 운동성 변화에 관한 연구

이성구,김명완,김홍자,서동환,이상수,김동일,유교상,주연호,민병일,김지훈 경희대학교 동서의학연구소 2001 東西醫學硏究所 論文集 Vol.2000 No.-

Background/Aims: This study was designed to evaluated the effects of electroacupuncture on the sphincter of Oddi (SO) motility in humans and to correlate the manometric findings with plasma cholecystokinin (CCK) levels. Methods: Eleven patients (M: F= 5: 6) who had various kinds of biliary disorders were enrolled. SO motility was monitored with a conventional low-compliant continuously perfused technique using ERCP (n=9) or percutaneous transhepatic cholangioscope (n=2). After baseline monitoring for phasic wave contractions of SO, electroacupuncture was applied at a specific acupoint, GB 34, in these 11 patients. A nonspecific acupoint 5 cm away from GB 34 was selected as a control. Manometric parameters of SO were also checked in 6 subjects during stimulation of the control acupoint. CCK plasma levels were measured during the time course of electroacupuncture stimulation. Result: All the manometric parameters including the basal pressure of SO, amplitude, frequency and duration of phasic wave contraction of SO were significantly decreased (p< 0.05) during electroacupuncture stimulation. The inhibition of SO contractility was accompanied by increased CCK plasma levels. After removal of electroacupuncture stimulation, restoration of amplitude and duration to basal condition were noted. A tendency towards the return of SO contractility was also observed in basal pressure and frequency. Stimulation of the control acupoint, however, did not affect the SO contractility and plasma CCK levels. Conclusions: Electroacupuncture stimulation of acupoint GB 34 showed reversible inhibition of SO contraction in humans. We speculate that the response of SO to electroacupuncture stimulation may be mediated by some neurohormonal mechanisms including CCK release. (Korean Journal of Gastrointestinal Motility 2000;6:44-41)

GPS Anomaly Analysis and Pseudorange Accuracy Improvement by Anomalous Satellite Elimination

Yoo, Yun-Ja,Cho, Deuk-Jae,Park, Sang-Hyun Korean Institute of Navigation and Port Research 2010 한국항해항만학회지 Vol.34 No.7

GPS anomaly has increased according to the degradation of satellite performance, and many GPS users could be exposed to any kinds of error-included signals without any previous notice when unscheduled error occurred. RSIM (Reference Station Integrity Monitors) is a typical monitoring method to broadcast PRC (Pseudo Range Correction) for users. However, there were some cases that the receiver detected the anomalous satellite's signal even though it was unhealthy set, consequently it occurred a large range error. Then it is important to monitor the integrity of GPS signal and it is needed to devise the correction method of pseudorange by eliminating error-occurred PRN for notification to GPS users when it is monitored that the anomaly occurred. This paper proposes the basic concept of how to correct the pseudorange. The paper also shows the analysis results of PRN10 GPS anomaly occurred on day 39 in 2007 with corrected results by eliminating anomaly satellite (PRN10). The proposed correction method shows decreased pseudorange error range compared to the case when the anomaly satellite were used.

Experimental Results of Ship's Maneuvering Test Using GPS

Yoo, Yun-Ja,Naknma, Yoshiyasu,Kouguchi, Nobuyoshi,Song, Chae-Uk Korean Institute of Navigation and Port Research 2009 한국항해항만학회지 Vol.33 No.2

The Kinematic GPS is well known to provide a quite good accuracy of positioning within an level. Although kinematic GPS assures high precision measurement on the basis of an appreciable distance between a reference station and an observational point, it has measurable distance restriction within 20 km from a reference station on land. Therefore, it is necessary to make out a simple and low-cost method to obtain accurate positioning information without distance restriction In this paper, the velocity integration method to get the precise velocity information of a ship is explained. The experimental results of Zig-zag maneuver and Williamson turn as the ship's maneuvering test, and other experimental results of ship's movement during leaving and entering the port with low speed were shown. From the experimental results, ship's course, speed and position are compared with those obtained by kinematic-GPS, velocity integration method and dead reckoning position using Gyro-compass and Doppler-log.

Experimental Results of Ship-To-Ship Lightering Operations Applied Velocity Information GPS

Yoo, Yun-Ja,Pedersen, Egil,Kouguchi, Nobuyoshi,Song, Chae-Uk Korean Institute of Navigation and Port Research 2014 한국항해항만학회지 Vol.38 No.6

A ship-to-ship (STS) lightering operation takes place in order to transfer cargo (e.g. crude oil or petroleum products) between an ocean-going ship and a service ship alongside it. Instrumental measurements to accurately determine the relative speeds and distances during the approach between the vessels would benefit the operational safety and efficiency. A velocity information GPS (VI-GPS) system, which uses the instantaneous velocity measures from carrier-phase Doppler measurement, has been applied in a field observation onboard a service ship (Aframax tanker) approaching a ship-to-be-lightered (VLCC) in open waters. This article proposes to apply VI-GPS as the input sensor to a guidance and decision-support system aiming to provide accurate velocity information to the officer in charge of an STS operation. A method for precise velocity measurement using VI-GPS was described and the measurement results were compared each other with the results of Voyage Data Recorder (VDR) and VI-GPS that showed the concept of a guidance and decision-support system applying VI-GPS with the field test results during STS operations. Also, it turned out that VI-GPS has sufficient accuracy to serve as an input sensor from the field test results.

Tropospheric Anomaly Detection in Multi-Reference Stations Environment during Localized Atmospheric Conditions-(2) : Analytic Results of Anomaly Detection Algorithm

Yoo, Yun-Ja Korean Institute of Navigation and Port Research 2016 한국항해항만학회지 Vol.40 No.5

Localized atmospheric conditions between multi-reference stations can bring the tropospheric delay irregularity that becomes an error terms affecting positioning accuracy in network RTK environment. Imbalanced network error can affect the network solutions and it can corrupt the entire network solution and degrade the correction accuracy. If an anomaly could be detected before the correction message was generated, it is possible to eliminate the anomalous satellite that can cause degradation of the network solution during the tropospheric delay anomaly. An atmospheric grid that consists of four meteorological stations was used to detect an inhomogeneous weather conditions and tropospheric anomaly applied AWSs (automatic weather stations) meteorological data. The threshold of anomaly detection algorithm was determined based on the statistical weather data of AWSs for 5 years in an atmospheric grid. From the analytic results of anomaly detection algorithm it showed that the proposed algorithm can detect an anomalous satellite with an anomaly flag generation caused tropospheric delay anomaly during localized atmospheric conditions between stations. It was shown that the different precipitation condition between stations is the main factor affecting tropospheric anomalies.

Tropospheric Anomaly Detection in Multi-reference Stations Environment during Localized Atmosphere Conditions-(1) : Basic Concept of Anomaly Detection Algorithm

Yoo, Yun-Ja Korean Institute of Navigation and Port Research 2016 한국항해항만학회지 Vol.40 No.5

Extreme tropospheric anomalies such as typhoons or regional torrential rain can degrade positioning accuracy of the GPS signal. It becomes one of the main error terms affecting high-precision positioning solutions in network RTK. This paper proposed a detection algorithm to be used during atmospheric anomalies in order to detect the tropospheric irregularities that can degrade the quality of correction data due to network errors caused by inhomogeneous atmospheric conditions between multi-reference stations. It uses an atmospheric grid that consists of four meteorological stations and estimates the troposphere zenith total delay difference at a low performance point in an atmospheric grid. AWS (automatic weather station) meteorological data can be applied to the proposed tropospheric anomaly detection algorithm when there are different atmospheric conditions between the stations. The concept of probability density distribution of the delta troposphere slant delay was proposed for the threshold determination.

Existing System Improvement and Expected Configuration based on Risk Control Options for Implementation of e-Navigation

Yoo, Yun-Ja Korean Institute of Navigation and Port Research 2018 한국항해항만학회지 Vol.42 No.2

Common Maritime Data Structure (CMDS) is commonly used by shore and ship users in e-Navigation data domain. In the overarching of e-Navigation architecture, IHO uses S-1XX, a digital exchange standard for next-generation marine information, as data exchange standard. The current CMDS has the advantage of intuitively recognizing the overall structure of e-Navigation. However, it has disadvantage in that it does not allow stakeholders to easily understand benefits that e-Navigation can provide when implementing e-Navigation. In this study, the direction of improving existing system for effective e-Navigation implementation was proposed considering RCOs (Risk Control Options) with expected composition of ship/ shore/ communication system by sector.

Tropospheric Anomaly Detection in Multi-reference Stations Environment during Localized Atmosphere Conditions-(1) :

Yun-Ja Yoo 한국항해항만학회 2016 한국항해항만학회지 Vol.40 No.5

Extreme tropospheric anomalies such as typhoons or regional torrential rain can degrade positioning accuracy of the GPS signal. It becomes one of the main error terms affecting high-precision positioning solutions in network RTK. This paper proposed a detection algorithm to be used during atmospheric anomalies in order to detect the tropospheric irregularities that can degrade the quality of correction data due to network errors caused by inhomogeneous atmospheric conditions between multi-reference stations. It uses an atmospheric grid that consists of four meteorological stations and estimates the troposphere zenith total delay difference at a low performance point in an atmospheric grid. AWS (automatic weather station) meteorological data can be applied to the proposed tropospheric anomaly detection algorithm when there are different atmospheric conditions between the stations. The concept of probability density distribution of the delta troposphere slant delay was proposed for the threshold determination.

Basic Architecture of Navigation Safety Module in S2 Service of Korean e-Navigation System

Yoo, Yun-Ja,Kim, Tae-Goun,Moon, Serng-Bae Korean Institute of Navigation and Port Research 2018 한국항해항만학회지 Vol.42 No.5

IMO introduced the concept of e-Navigation and proposed MSPs(Maritime Service Portfolios) concept to reduce marine accidents, to improve efficiency of ship operation, port operation, and ship operation technology. Korean e-Navigation defines S1 ~ S5 services, as the service concept focused on domestic e-Navigation service corresponding to IMO MSPs, and is constructing a system as an ongoing project. S2 service (onboard system remote monitoring service) among the concepts of Korean e-Navigation services, is a service concept that judges the emergency level according to risk if an abnormal condition occurs during navigation, and provides corresponding guidance to accident ships based on emergency level. The purpose of this paper is to provide a basic architecture proposal of Korean e-Navigation S2 service navigation safety module, based on the S2 service operation concept. To do this, we conducted a questionnaire survey to ask experts with experience with sailors, to respond to the subjective risk experienced by sailors considering effects of anomalies, including equipment failure relative to sailing and navigational safety. Risk level for each abnormal condition was classified. The basic algorithm design of the navigation safety module is composed of safety index (SI) calculation module based on results of questionnaire and expert opinions, safety level (SL) determination module according to safety index, and corresponding guidance generation module according to safety level. To conduct basic validation of basic architecture of the navigation safety module, simulation of the ship anomaly monitoring was performed, and results have been revealed.