• Industry Promotion Research
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• v.8 no.2
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• pp.157-164
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• 2023

Since there are no related laws and regulations in the Korean private investigation industry, anyone can freely operate it if they report the business to the tax office. The reality is that companies hire PI to investigate rival companies and employees for specific reasons, as they generally rely on individual requests. The Korean PI industry is divided into two parts. The first are retired police officers and investigators who have experience in criminal investigation. The second are private citizen who can conduct investigation service activities runs a PI agency after everyone has registered with the tax office. It is no exaggeration to say that the current legal conflicts and legal problems that arise in the PI service cannot be ruled out because civilians are relatively less knowledgeable than PIs and legal experts. Therefore, in order for PI industry to operate stably in Korea, we will first study the concept and type of PI industry, comparative analysis of past PI laws, current status and reality of PI industry, and study the current status and references.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.97-103
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• 2022

An aircraft component can only be mounted on an aircraft if it has been certified to have a structural robustness under flight load conditions. Among the major components of the aircraft, a pylon is a structure that connects external equipment such as an engine, and external attachments with the main wing of an aircraft and transmits the loads acting on it to the main structure of the aircraft. In civil aircraft, when there is an incident of fire in the engine area, the pylon prevents the fire from spreading to the wings. This study presents the results of structural static tests performed to verify the structural robustness of a fuel pylon used to mount external fuel tank in an aircraft. In the main text, we present the test set-up diagram consisting of test fixture, hydraulic pressure unit, load control system, and data acquisition equipment used in the structure static test of the fuel pylon. In addition, we introduce the software that controls the load actuator, and provide a test profile for each test load condition. As a result of the structural static test, it was found that the load actuator was properly controlled within the allowable error range in each test, and the reliability of the numerical analysis was verified by comparing the numerical analysis results and the strain obtained from the structural test at the main positions of the test specimen. In conclusion, it was proved that the fuel pylon covered in this study has sufficient structural strength for the required load conditions through structural static tests.

• Korean Journal of Cognitive Science
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• v.34 no.2
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• pp.85-110
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• 2023

The gaze cueing effect appears as detecting a target rapidly and accurately when the direction of others' gaze corresponds with the location of the visual target. The gaze cue can be affected by the orientation of the face. The gaze cueing effect is strong when the face is presented upright, but the effect has only been observed in some studies when the face is presented inverted(e.g., Tipples, 2005). This study aimed to examine whether the gaze can operate as a cue to guide attention with upright faces, and to add variables that can affect the gaze cue, such as the orientation of the face, the orientation of the background, and a time interval between the gaze cue and the target(SOA). Furthermore, it systematically manipulated these variables to explore whether the gaze cueing effect can be observed under the various conditions. The results showed a significant gaze cueing effect even on the inverted face, contrasting with previous studies. These findings were consistently observed when the background stimulus was absent(Experiment 1) and present(Experiments 2 and 3). However, there was no significant interaction in the orientations between the face and the background. Moreover, in the short SOA(150 ms), we found a significant gaze cueing effect in conditions of every face and background orientation, whereas there was no significant gaze cueing effect in the long SOA(1000 ms). By presenting a consistent observation of the gaze cueing effect under the short SOA(150ms) even in the inverted faces, the results of this study pose questions about the reliability and repeatability of previous studies that did not report significant results of gaze cueing effects in that faces. Furthermore, our results are meaningful in providing additional evidence that attention can be guided toward the direction of the gaze even in various directions of the face and background.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.64-75
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• 2022

The ITS performance evaluation has been performed in the evaluation of traffic data collection equipment. However, evaluation of the data collection equipment alone cannot guarantee the reliability of the traffic information. So, ITS service evaluation has to be implemented institutionally. In this study, an evaluation method has been prepared to evaluate the accuracy of travel time information in road sections. In addition, a piece of portable reference equipment was developed to collect travel time data on the road. Field tests were performed on two national road sections managed by the Seoul Construction and Management Administration (SCMA) to prepare an evaluation method considering field conditions and evaluate the reference equipment's performance. Based on the test results, the improvement of the reference equipment to collect more samples and the adjustment of collection points were discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4C
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• pp.231-238
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• 2008

A column testing device capable of measuring the electrical resistivity of soil at 3 different locations was developed to verify applicability of bulk electrical conductivity (BEC) breakthrough curves in monitoring contaminant transport. Tracer injection tests were conducted with three different types of saturated sands to obtain average linear velocities and longitudinal hydrodynamic dispersion coefficients based on BEC breakthrough curves and effluent solute breakthrough curves. Comparative analysis of transport parameters obtained from curve fitting the results into the analytical solutions confirmed the validity of resistance measurements in estimating time-continuous resident solute concentration. Under the assumption that a linear relationship exists between ${\sigma}_{sat}-{\sigma}_w-C$, the BEC breakthrough curves are able to effectively reduce the laborious and time-consuming processes involved in the conventional method of sampling and analysis. In order to reduce possible uncertainties in analyzing the BEC breakthrough curves, it was recommended that resistance measurements take place nearby the effluent boundary. In addition, a sufficient electrical contrast or difference in the electrical conductivity of the influent and the saturating solution is required to conduct reliable analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5B
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• pp.479-486
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• 2010

Reliable hydrologic data acquisition is the basic and essential requirement for efficient water management. Especially the acquisition of various stream data in a certain location is very important to construct on alarm system to response an urban flood which occurs frequently due to the effect of climate change. Although the frequency of stream inundation flood occurrence becomes low owing to the consistent stream improvement, the urban flood due to the drainage system problems such as deterioration and bad management occurs continuously. The consistent management and current status understanding of the urban drainage system is essential to reduce the urban flood. The purpose of this study is to develop the urban runoff network flow velocity monitoring system which has the capability of collecting stream data whenever, wherever and to whomever without expert knowledge using Code Division Multiple Access technique and Bluetooth near-distance wireless communication technique. The urban runoff network flow velocity monitoring system consists of three stages. In the first stage, the stream information obtained by using ubiquitous floater is transferred to the server computer. In the second stage, the current state of the urban drainage system is assessed through the server computer. In the last stage, the information is provided to the user through a GUI. As a result of applying, the developed urban runoff network flow velocity monitoring system to Woncheon-Stream in Suwon, the information necessary for urban drainage management can be managed in real time.

• 한국노년학
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• v.30 no.3
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• pp.815-830
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• 2010

This study is a nonequivalent control group pretest-posttest study to determine the effects of a make up program on the self-esteem and anxiety of the elderly female dementia patients. This research was done between April 13th and May 1st, 2009. The subjects were 41 dementia patients in an elderly hospital in Honam Area. Twenty dementia patients in the experimental group got the make up measures during the two week experimental period and twenty one dementia patients in the contrast group didn't get any measure during the two week period. Make up measures were given to the experimental group 10 times for the two week period. This study used the self-esteemscale which was developed by Rosenberg(1965) and was translated and modified by Jeon Pyung Je(1974) into Korean. The anxiety status scale which this study used was developed by Spielberger(1970) and was translated and modified by Kim Jeong Taek(1991) into Korean. Collected data were analyzed with SPSS Win 12.0. T-test and multivariate analysis were done to test the hypothesis. This study also used a method of observation. The results of this study are following. After the two week make up measures, the experimental group had more self esteem and less anxiety status than the contrast group. The differences were statistically significant. The result of the observation also supported the research hypothesis. Based on this result, we suggest the make up program as an appropriate and useful nursing care intervention program for female dementia patients.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.704-711
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• 2023

This paper discusses the control method of BLDC(Brushless Direct Current) motor that has similar electrical characteristics with DC motor but has improved its lifespan and reliability. The BLDC motor can improve durability and speed stability by using rotor position information to eliminate commutators that require mechanical contact with DC motors. In this study, a controller for a DC motor was designed based on the fact that the current in the windings of a BLDC motor is a square-wave current like the current flowing in the armature of a DC motor. Next, the designed controller was applied to a 3-phase BLDC motor to confirm the effectiveness of the controller. In detail, a single-phase DC motor with electrical parameter values of a three-phase BLDC motor was modeled and a PI controller for motor speed control was designed by applying the root locus method to the derived system. The speed control simulation of the DC motor was performed to confirm the validity of the controller, and the same controller was applied to the speed control of the 3-phase BLDC motor implemented in MATLAB. From the simulation, similar results of the DC motor were obtained in the 3 phase BLDC motor and confirmed the usefulness of the proposed control scheme.

• Tunnel and Underground Space
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• v.33 no.5
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• pp.348-372
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• 2023

In relation to the high-level radioactive waste disposal project in deep fractured rock aquifer environments, it is essential to evaluate hydrogeological characteristics for evaluating the suitability of the site and operational stability. Such subsurface hydrogeological data is obtained through in-situ tests using boreholes excavated at the target site. The accuracy and reliability of the investigation results are directly related to the selection of appropriate test methods, the performance of the investigation system, standardization of the investigation procedure. In this report, we introduce the detailed procedures for the representative test method, the constant pressure injection test (CPIT), which is used to determine the key hydrogeological parameters of the subsurface fractured rock aquifer, namely hydraulic conductivity and storativity. This report further refines the standard test method suggested by the KSRM in 2022 and includes practical field application case conducted in volcanic rock aquifers where this investigation procedure has been applied.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.147-156
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• 2023

Because the behavior of cable bridges is dominated by dynamic response and is relatively complex, short- and long-term field monitoring are often required to evaluate the bridge condition. If a permanent SHMS (Structural Health Monitoring System) is not installed, a portable monitoring system is needed for the checking of bridge condition. In this case, it can be difficult to operate the portable monitoring system due to limited conditions such as power and communication according to the location and type of the bridge. In this study, the portable-based smart structural response monitoring system is developed that can be effectively used for short- and long-term monitoring of cable bridges in Korea and Southeast Asia. The developed system is a multi-channel portable data acquisition and analyzer that can be operated for a long time in the field using its own power supply system, and is included with the automated analysis algorithm for the dynamic characteristics of cable bridges using real-time data. In order to evaluate the field applicability of the developed system, field demonstration was conducted on cable bridges in Korea and Vietnam. Through the demonstration, the reliability and efficiency of field operation of the developed system were confirmed, and additionally, the possibility of application to overseas markets was confirmed in cable bridge monitoring field.