• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.1
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• pp.20-25
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• 1990

During the summer of 1989, the authors carried out the hydroacoustic surverys to investigate the vertical distribution of volume backscattering strength in the East China Sea and simultaneously the biological sampling of the scattering layers by bottom trawling. The echoes from the scattering layers was continuously measured by using a 50 kHz echo sounder during the day and night. A data acquisition system was used to record digitally the envelope of the echoes and the echo integration technique was used to determine the scattering strength proportional to biomass density in each layer. The vertical profiles of volume backscattering strength also were compared with the one of water temperature. The results obtained can be summarized as follows: 1. The vertical profiles of mean volume backscattering strength at day and night suggested that during the night the biggest fish concentrations appeared in the mixed layer above the thermocline and during the day near the bottom. In another profiles where the thermocline was not well developed, peaks in scattering appeared at midwater depths and near the bottom. 2. The maximum values of mean volume backscattering strengths varied from -49.3 dB to -48.0 dB on different regions and at different times of the day and night. 3. Trawl data indicated that the organisms consisting of the scattering layer near the bottom were squid and various species of demersal fishes.

• Geophysics and Geophysical Exploration
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• v.15 no.1
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• pp.33-38
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• 2012

A resistivity method has been applied to wide range of engineering and environmental problems with the help of automatic and precise data acquisition. Thus, more accurate modeling and inversion of time-lapse monitoring data are required since resistivity monitoring has been introduced to quantitatively find out subsurface changes With respect to time. Here, we used the finite element method (FEM) for 3D resistivity modeling since the method is easy to realize complex topography and arbitrary shaped anomalous bodies. In the FEM, the linear elements, also referred to as first order elements, have certain advantages of simple formulation and narrow bandwidth of system equation. However, the linear elements show the poor accuracy and slow convergence of the solution with respect to the number of elements or nodes. To achieve the higher accuracy of finite element solution, high order elements are generally used. In this study, we developed a 3D resistivity modeling program using high order Serendipity elements. Comparing the Serendipity element solutions for a cube model with the linear element solutions, we assured that the Serendipity element solutions are more accurate than the linear element solutions in the 3D resistivity modeling.

• Journal of Technology Innovation
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• v.29 no.4
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• pp.1-30
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• 2021

Due to the recent development of system semiconductors, technical innovation for the electric devices of the automobile industry is rapidly progressing. In particular, the electric device of automobiles is accelerating technology development competition among automobile parts makers, and the development cycle is also changing rapidly. Due to these changes, the importance of strategic planning for R&D is further strengthened. Due to the paradigm shift in the automobile industry, the Product-Technical Roadmap (P/TRM), one of the R&D strategies, analyzes technology forecasting, technology level evaluation, and technology acquisition method (Make/Collaborate/Buy) at the planning stage. The product-technical roadmap is a tool that identifies customer needs of products and technologies, selects technologies and sets development directions. However, most companies are developing the product-technical roadmap through a qualitative method that mainly relies on the technical papers, patent analysis, and expert Delphi method. In this study, empirical research was conducted through simulations that can supplement and strengthen the product-technical roadmap centered on the automobile industry by fusing Gartner's hype cycle, cumulative moving average-based data preprocessing, and deep learning (LSTM) time series analysis techniques. The empirical study presented in this paper can be used not only in the automobile industry but also in other manufacturing fields in general. In addition, from the corporate point of view, it is considered that it will become a foundation for moving forward as a leading company by providing products to the market in a timely manner through a more accurate product-technical roadmap, breaking away from the roadmap preparation method that has relied on qualitative methods.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.1
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• pp.53-62
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• 2017

In this paper, we present the score classification accuracy of BBS(Berg Balance Scale) which is the most commonly used balance evaluation tool using machine learning. Data acquisition was performed using the Noraxon system and an inertial sensor of Noraxon system was attached to the body in 8 locations (left and right ankle, left and right upper buttocks, left and right wrists, back, forehead). Based on the 3-axis accelerometer of the inertial sensor, the feature vector STFT(Short Time Fourier Transform) and SAM(Signal Area Magnitude) were extracted. Then, the items of the BBS were divided into static movement and dynamic movement depending on the operation characteristics, and the feature vectors were selected according to the sensor attachment positions which affect the score for each item of the BBS. Feature vectors selected for each item of BBS were classified using GMM(Gaussian Mixture Model). As a result of the accuracy calculation for 40 subjects, 55.5%, 72.2%, 87.5%, 50%, 35.1%, 62.5%, 43.3%, 58.6%, 60.7%, 33.3%, 44.8%, 89.2%, 51.8%, 85.1%, respectively.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.26-37
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• 2009

Ministry of Land, Transportation and Marine Affairs(MLTM) has implemented Construction CALS project for improving productivity of construction industry and for making construction project management efficient by responding to informatization and knowledge base society in 21st century. CALS has beeb applied successfully to projects form MLTM, however, the outcomes of Construction CALS hasn't been recognized. In addition, there is no way to find how high the level of Construction CALS is when it is compared with other SOC informatization projects. This study found out the informatiziation level of Construction CALS by using the evaluation index proposed in the former study, and by comparing with other sectors. The evaluation on the level was implemented in the three parts such as informatization infrastructure(network, hardware, standardization, data, informatization, informatization security), informatization utilization(information usage, IT performance), and informatization support(informatization goal, organization of informatization, informatization investment, informatization education), and then, this evaluation was compared with "Assessment for level of industry information system", "Assessment for level of small and midium sized industry information system", and "IICI(Informatizaion Index for the Construction Industry)". With the result from the comparison, this study produced superior factors and inferior factors for each sector. These results are expected to be useful for prioritizing budget allocation by finding out the informatization level of Construction CALS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.648-654
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• 2018

Currently, the Defense Agency for Technology and Quality (DTaQ), which is responsible for the quality assurance of military supplies, divides munitions into four categories, in order to conduct its governmental quality assurance activities, including product examination, process review and system audit. However, these 4 categories may differ depending on the related organizations' (e.g. Defense Acquisition Program Administration, munitions manufacturing) military requirements. Therefore, in this study, appropriate classification criteria for munitions are suggested for the sake of the efficient procurement, production and quality assurance of military supplies. We investigated the item classification system of the Public Procurement Service, which is a similar organization to the DTaQ. We also compared the appropriate classification criteria with those of related organizations and identified the current status of munitions classification data according to the current standard. In addition, application samples are presented using the proposed quality assurance classification criteria. Finally, the classification criteria of military supplies proposed in this paper will contribute to improving the efficiency of government quality assurance activities.

• Tunnel and Underground Space
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• v.28 no.3
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• pp.258-276
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• 2018

The accurate and quantitative ground information on the hydraulic conductivity characteristics of rock mass is one of the key factors for evaluation of the hydro-geological behaviour of rock mass around an excavated opening under high water pressure. For tunnel and rock structures in seabed, where the sea acts as an infinite source of water, its importance become greater with increasing construction depth below sea level. In this study, to improve the problems related with poor system configuration and incorrect data acquisition of previous hydraulic packer testing equipment, we newly developed an integrated main frame and 30 bar level waterproof downhole sonde apparatus, which were optimized for deep hydraulic packer test in seabed rock mass. Integration of individual test equipment into one frame allows safe and efficient field testing work on a narrow offshore drilling platform. For the integrated type main frame, it is possible to make precise stepwise control of downhole net injection pressure at intervals of $2.0kg_f/cm^2$ or less with dual hydraulic oil volume controller. To ensure the system performance and the operational stability of the prototype mainframe and downhole sonde apparatus, the field feasibility tests were completed in two research boreholes, and using the developed apparatus, the REV(Representative Elementary Volume) scale deep hydraulic packer tests were successfully carried out at a borehole located in the basalt region, Jeju. In this paper, the characteristics of the new testing apparatus are briefly introduced and also some results from the laboratory and in-situ performance tests are shown.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.711-722
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• 2020

The purpose of this study was to investigate the effectiveness of utilization level and to propose the improvement related in obtaining qualification for senior sports instructors. The population of this study was participants who took the course of the general course and special course Training Program for Sports Instructors for senior in JeollaNam-do from 2015 to 2017. A total of 113 of them answered the survey. The data process of this study was used by the IBM SPSS Statistics 25.0 program, and frequency analysis was conducted. The results of this study are follows. First, What was your situation when they took the qualifications program of sports instructor for senior, the largest number of answer were 'working in the sports field'. Most respondents answered that the reason for acquisition was to have various abilities. Second, The qualification of sports instructor for senior helped person get a job but did not help with promotions or wage increases. the largest number of answer to the reason were'the lack of benefits from qualification'. At the national level, the system of sport instructor qualification for senior must be an important system for preparing for future social problems and maintaining a healthy society. In order to be effective, however, the training program should be strengthened for the senior and provide professional experiences.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.5
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• pp.648-654
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• 2004

The Mass Flow Controller(MFC) has become crucial in semiconductor manufacturing equipments. It is an important element because the quality and the yield of a semiconductor process are decided by the accurate flow control of gas. Therefore, the demand for implementing the high speed and the highly accurate control of MFCs has been increasing. It is hard to find an article of the control algorithm applied to MFCs. But, it is known that commercially available MFCs adopt PID control algorithms. Particularly, when the system detects the flow by way of heat transfer, the MFC control problem includes the slow response and the nonlinearity. In this paper, MFC control algorithm with a superior performance to the conventional PID algorithm is discussed and the superiority is demonstrated through the experiment. A fuzzy controller was utilized in order to compensate the nonlinearity and the slow response, and the performance is compared with that of an MFC currently available in the market. The control system, in this paper, consists of a personal computer, the data acquisition board and the control algorithm carried out by LabWindows/CVI program on the PC. In addition, a method of estimating the actual flow from the sensor output with the slow response is presented. In conclusion, according to the result of the experiment, the proposed algorithm shows better accuracy and is faster than the conventional controller.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.98-107
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• 2016

The purpose of this study is for Human error prevention to acquire Collision Risk Perception Index (CRPI) sensed by the Officer Of the Watch (OOW) when the approaching distances are reduced in six types of ship encountering situations (Head on, $045^{\circ}$, $090^{\circ}$, $135^{\circ}$, Overtaking, Overtaken) between own ship and a target ship and then to predict CRPI fitting coefficients with polynomials in the curve-fitting process. CRPI acquisition experiments are carried out on two coast-guard ships and with the total of 30 crew members. Analysing results shows that CRPI data have goodness of fit to the six types of encountering situation. Futhermore, the One-Way ANOVA results show that CRPI has a negative affect to the OOW's age, career and license grade as the approaching distances is reduced. The availability of CRPI curve fitting with 3 degrees of polynomial was testified through the RMSE as 1.19 to Head on, 0.87 to $045^{\circ}$, 0.81 to $090^{\circ}$, 0.71 to $135^{\circ}$, 1.29 to Overtaking and 0.87 to Overtaken.