• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.120-127
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• 2020

This study examined the operation of a pressure gauge for measuring the internal pressure of a barrel. During the ammunition performance evaluation test, the internal pressure of the barrel was measured mainly using a copper crusher gauge. The internal piezo gauge (IPG) was used to replace the pressure measurement method, and the test results were analyzed to verify the operability of the IPG. For verification, actual shooting test data were used, and a t-test was used to analyze the results. The 155MM KH179 and M119 series propellant were used for the test equipment and ammunition. The results confirmed that there was no difference between the mean values of the two data results at a significance level of 5% for the data values between the copper gauge and the IPG. The use of the IPG was verified by replacing the existing copper gauge to measure the internal pressure of the barrel, and it was confirmed that the application width could be widened in terms of diversity of test measurement methods. Based on the results of this test, it can be applied to the compression measurement test of various types of ammunition in addition to the propellant charges.

• Composites Research
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• v.30 no.6
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• pp.384-392
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• 2017

Sandwich panels with three different joint configurations were tested to design a novel sandwich joint structure that can effectively support both the tensile and compressive loads. The sandwich core was mainly aluminum flex honeycomb but the PMI foam core was limitedly applied to the ramp area which is transition part from sandwich to solid laminate. The face of sandwich panel was made of carbon fiber composite. For configuration 1, the composite flange and the sandwich panel were cocured. For configurations 2 and 3, an aluminum flange was fastened to the solid laminate by HI-LOK pins and adhesive. The average compressive failure loads of configurations 1, 2, and 3 were 295, 226, and 291 kN, respectively, and the average tensile failure loads were 47.3 (delamination), 83.7 (bolt failure), and 291 (fixture damage) kN, respectively. Considering the compressive failure loads only, both the configurations 1 and 3 showed good performance. However, the configuration 1 showed delamination in the corner of the composite flange under tension at early stage of loading. Therefore, it was confirmed that the structure that can effectively support tension and compressive loads at the same time is the configuration 3 which used a mechanically fastened aluminum flange so that there is no risk of delamination at the corner.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.193-202
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• 2018

This paper proposed a crack spacing calculation formulation which is an important parameter for calculating the crack width, that is the main factor for verification of serviceability limit states and durability performance evaluation of reinforced concrete members. The basic equation of average crack spacing is derived by considering the bond characteristics which is the governing equation for the analysis of cracking behavior in reinforced concrete members. In order to consider the effect of the cover thickness and concrete compressive strength, the crack spacing measured in 124 direct tensile tests performed by several researchers was analyzed and each coefficient was proposed. And, correlation analysis was performed from 80 specimen data where the maximum and average crack spacing were simultaneously measured, and a correlation coefficient that can easily predict the maximum crack spacing from the average crack spacing was proposed. The results of the proposed average crack spacing equation and maximum crack spacing correlation were compared with those current design code specification. The comparisons of proposed equations and the Korean design codes show that the proposed formulation for the average crack spacing and the maximum crack spacing improves the accuracy and reliability of prediction compared to the corresponding provisions of the Korean Concrete Structural Design Code and Korean Highway Bridge Design Code (Limit States Design).

• Journal of Biomedical Engineering Research
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• v.23 no.3
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• pp.217-225
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• 2002

The implantable middle ear(IME) system, which has good sound quality. superior sound intelligibility and wide frequency characteristics. can resolve the sound distortion and ringing effect by sound feedback at high gain operation those are the major problems of conventional hearing aid. In this paper, we have manufactured the IME system using differential electromagnetic transducer(DET) and verified the performance of the system by carrying out vibration and animal implanting experiment. The DET was manufactured using micro-machining technology and vibration experiment of the transducer was performed to inspect whether the transducer could vibrate in accordance with the applied sound signal or not. And the result of the loaded experiment using temporal bone sampled from cadaver showed that the transducer can drive the middle ear bone and transmit the signal to inner ear After the internal unit of IME system was implanted in a dog. the auditory brainstem response (ABR) test was carried out. The result of the test indicated the Proper behavior of the IME system in the living body From the results of the experiments, it is verified that the manufactured system ewll work well when it is applied to human and a basis of clinical experiment of IME system to real human hearing impaired was be arranged.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.175-181
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• 2009

Intelligent Transportation Systems(ITS) enables road users to enhance efficiency of their trips in a variety of traffic conditions. As a significant part of ITS, information communication technology among vehicles and between vehicles and infrastructure has been being developed to upgrade current traffic data collection technology through location-based traffic surveillance systems. A wider and detailed range of traffic data can be acquired with ease by the technology. However, its performance level falls with environmental impediments such as large vehicles, buildings, harsh weather, which often bring about wireless communication failure. For imputation of vehicle trajectory data discontinued by the failure, several potential existing methods were reviewed and a new method to complement them was devised. AIMSUN API(Application Programming Interface) software was utilized to simulate vehicle trajectories data and missing vehicle trajectories data was randomly generated for the verification of the method. The method was proven to yield more accurate and reliable traffic data than the existing ones.

• Fire Science and Engineering
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• v.31 no.6
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• pp.40-46
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• 2017

As one of the solutions to deal with economic loss caused by traffic congestion in metropolitan area, a deep underground road has been planned and implemented at home and abroad. The part of them has been pushed ahead with a double-deck scheme which has an advantage in constructability and cost efficiency comparing to traditional road tunnel. However, the double-deck tunnel has a lower floor height than the general road tunnel due to the special structure used as the upper and lower lines by installing the middle slab on one excavation section. Therefore, it is relatively weak against fire accidents and ventilation problems occurring in tunnels. Thus study to develop the life safety system optimized to a double-deck tunnel has been systematically carried out in order to overcome their weak point. In this study, automatic monitoring fire extinguisher (AMFE) is developed to suppress a fire and prevent its spread at early stage of tunnel fire, conducting the performance test through vehicle fire tests as verification. The tests were conducted with AMFE being 30 m apart from the vehicle and 10 m apart from engine room. As a results, it was confirmed that AMFE enables to suppress a fire and prevent its spread in both cases.

• Journal of Society of Preventive Korean Medicine
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• v.21 no.3
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• pp.11-18
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• 2017

Objectives : In an effort to suggest a developmental plan of Traditional Korean Medicine health promotion project(TKM-HPP), this study was conducted to identify the problems experienced by public health Traditional Korean Medicine(PH-TKM) doctors in duty and to analyze successful cases of the health promotion project. Methods : Two PH-TKM doctors in duty at the Public Health Centre branch and Public Health Centre respectively, and one TKM doctor in charge of Public Health Centre participated in the in-depth interview. The research procedure was as follows; 1) inform study objectives and interview questions to participants, 2) in-depth interview with semi-structured questions, and 3) post-confirmation and verification. The interview was recorded and transcripted. In-depth interview was composed of 6 subsections: 1) Introducing participants and share purpose of interview, 2) Confirmation of the job status and difficulty of public health centre, 3) Reflecting and sharing experiences of public health clinic job performance cases, 4) Current status and improvement needs of TKM-HPP, 5) Discussions on improvement of TKM-HPP in public health center, 6) Sharing and reconfirmation of interview results. Thematic analysis was conducted from the narratives. Results : The study showed that; 1) the support from the local government was critical for the successful TKM-HPP and participation of the PH-TKMs; 2) the major problems experienced by PH-TKMs were lack of training for TKM-HPP in the field and lack of knowledge at local government level; 3) the suggestions to provide PH-TKMs with manual to educate residents effectively and redefine roles of PH-TKMs in the project. It also suggests that TKM-HPP model should be developed by the district in a way of reflecting regional characteristics. Conclusions : Firstly, more efforts should be made on the projects rather than medical treatment in public health centers, except for areas where medical institutions are scarce. Secondly, in order to facilitate participation of PH-TKM doctors, each local office should reduce medical care and increase efforts related with projects. Thirdly, the institution has to develop feasible TKM-HPP plans that can be carried out by PH-TKMs by the manual. Lastly, pre-training should be provided to PH-TKMs to understand contents of TKM-HPP related to public health centre work before the placement.

• Journal of the Society of Disaster Information
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• v.8 no.3
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• pp.310-318
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• 2012

Actual condition by items based on the level of execution of Construction Company certified by Construction Safety and Health Management Systems (KOSHA 18001) was investigated, analyzed and evaluated reflecting various opinions fincluding safety experts, top management, audit experts, and construction engineers. Currently, the maintenance is being managed through internal audit after the safety and health management system has been certified, but it is difficult to identify the degree of continuous improvement. In order to present the standards to see the level of quantified system, this study was conducted. The purpose of this study is to present the system maturity evaluation tool to be used to reduce occupational accidents through proper establishment and continuous improvement of national health and safety management system. Results of this study are summarized through identification of current condition of implementation of KOSHA 18001 system, development of maturity measurement tool and verification as follows: First, priority of implementation for activities of headquarters and on-site was determined by importance of activities such as the risk assessment, safety and health accident prevention activities, performance assessment and monitoring, resource management and support, and management review and improvement in order. In addition, the expert group presented that association with continuous improvement activities could establish the system by presenting strengths, weaknesses and improvement subjects of system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.485-492
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• 2012

Today, a digital airborne imaging sensor plays an important role in construction of the numerous National Spatial Data Infrastructure. However, an appropriate quality assesment procedure for the acquired digital images should be preceded to make them useful data with high precision and reliability. A lot of studies therefore have been conducted in attempt to assess quality of digital images at home and abroad. In this regard, many test fields have been already established and operated to calibrate digital photogrammetric airborne imaging systems in Europe and America. These test fields contain not only GCPs(Ground Control Points) to test geometric performance of a digital camera but also various types of targets to evaluate its spatial and radiometric resolution. The purpose of this paper is to present a method to verify the spatial resolution of the Intergraph DMC digital camera and its results based on an experimental field testing. In field test, a simple bar target to be easily identified in image is used to check the spatial resolution. Images, theoretically designed to 12cm GSD(Ground Sample Distance), were used to calculate the actual resolution for all sub-images and virtual images in flight direction as well as in cross flight direction. The results showed that the actual image resolution was about 0.6cm worse than theoretically expected resolution. In addition, the greatest difference of 1.5cm between them was found in the image of block edge.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.106-121
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• 2016

While economic crises are happening internationally due to the global financial crisis and the long-term recession of the domestic economy, South Korea is also experiencing an aging society with the retirement of the baby-boomers and a low birth-rate. The rapid retirement of baby-boomers, which is one of the essential parts of the Korean economy, is ongoing. Consequently, the number of seniors showing interest in entrepreneurship, as a way to avoid the economic threat, is increasing. Therefore, this study examined the correlation between two factors and its success, which can be stated as the influence of decision making in entrepreneurship and the influence of promotion policies to entrepreneurship. A survey was taken from 393 people, who received academic and managerial assistance from the Senior-Founded Support Center of Small Business Market Corporation and Adults Incubators of Seoul-Business Agency. and 'Hypothesis 1-1' and 'Hypothesis 2-2' were selected, because a positive effect was derived at each verification process. As a result, under the decision making types of entrepreneurship, only a reasonable type showed a positive effect at both the financial outcome and non-financial outcome of success, and the intuitive type was affected positively by the non-financial outcome. In addition, under the entrepreneur supporting business, among financial support, managerial support and educational support only managerial support had a positive effect.