• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.12 no.4
• /
• pp.387-394
• /
• 2019

The purpose of this study is to analyze and identify the strengths of companies selected in each field based on data released by the IOTONE to see if the most influential companies in the industrial Internet of Things are gaining high competitiveness by exercising their capabilities in each field. The industrial Internet of Things is emerging as an essential element in the overall realm of business activity, as well as to make manufacturing factories competitive smart factories. Appropriate platforms should be applied to apply the industrial Internet of Things throughout the enterprise. Globally, many companies are proposing a platform for the industrial Internet of Things. We analyzed the strengths of the most influential companies in each field of connected machines, cybersecurity, analysis platforms, embedded computing, platform connectivity and hardware connectivity in the industrial Internet of Things, and looked at trends such as the current state of operations and the characteristics of the platform.

• The Journal of the Acoustical Society of Korea
• /
• v.16 no.3
• /
• pp.13-17
• /
• 1997

This paper investigates the influence of material properties of the acoustic damping layer in the low noise hydrophone designed in the previous paper. For increase of the insensitivity of the hydrophone to external noises, acoustic impedance and damping coefficients are selected and the effects of the selected material property on the hydrophone response to the external noises are simulated with finite element method (FEM). The results show that the damping coefficients are not influential to the structural vibration decoupling from the sensing element. On the other hand, the optimum acoustic impedance of compliant layer is estimated which is smaller than 1 Mrayl or larger than 4 Mrayl. However polymer materials, which are in general use for acoustic window and damping layers, is not appropriate for the compliant materials of this hydrophone. Therefore development of new composite materials, i.e. ceramic-polymer composite or metal-ceramic composites etc., is required for the development of effective self noise suppressing underwater hydrophones.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.4
• /
• pp.1900-1907
• /
• 2012

Since the subpanels of polygonal-section shell have the corners of an obtuse angle larger than 90 degree unlike general plate or box-section structures, this could have an influence on forming nodal lines against local plate buckling or stress distributions. However, there is not sufficient material in the relevant study results or design recommendations. The very feasible models of the initial imperfections were acquired through the literature studies and then the parametric studies were conducted along with the initial imperfection models by using the finite element method. The parameters like the size of residual stresses, the portion of compressive residual stresses, and steel grades were considered. From the parametric studies, it was found that the maximum residual stress is more influential factor than the distribution pattern of residual stresses. In addition, The design strength equations for the simply supported plates can be applicable to the determination of the local buckling strength of the polygonal cross-section shell structures.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.12
• /
• pp.1563-1571
• /
• 2011

In this study, we developed a finite element model of the human middle ear has been developed to calculate itsfor sound transfer characteristics calculation. We usedThe geometric data forof ossicles, obtained byfrom micro-CT scanning, was used in order to develop the middle- ear FE model. A right- side temporal bone of a Korean cadaver was used for the micro-CT scanning. The developed FE model includes three ossicles, the tympanic membrane, ligaments, and muscles. We calculated theA sound transfer function from the tympanic membrane to the stapes footplate was calculated. The sound transfer function calculated vias of the FE model shows good agreement with measured responses over the 10- kHz frequency band. To measureidentify the sensitivityies of the middle- ear function due to material property variation, we studied several parameters studies have been fulfilled using the middle ear FE model. TAs a result the stiffness property of the incudostapedial joint had the greatest influence onwas the most influential to the middle- ear sound transfer function among the parameters.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.6D
• /
• pp.645-653
• /
• 2012

The productivity management of highway construction is required to innovate the efficiency of investment The productivity management of highway construction is required to innovate the efficiency of investment cost for newly constructed projects and to improve the quality of these projects, as the maintenance and management expenses are steadily increasing for existing highways under operation. However, clear criteria, methods or requirements to measure the productivity and performance in the construction of highways have not been properly established yet. This study defined 5 major elements of the productive projects in terms of construction management which is one of major tasks of the owner. There were the 43 influential elements significantly affecting on the productivity and these elements were categorized into the hierarchical structure which was composed of 3 levels. Also, this study conducted a survey for Korea Expressway Corporation who is the largest owner in Korea's highway construction. As a result, major project performance indicators, which should be addressed for management, to execute the projects successfully, are presented through understanding the extent of the affection of productivity elements on the elements of project performance to attain the productive projects and through understanding the extent of demand to be improved.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.36 no.4
• /
• pp.659-665
• /
• 2016

The limit equilibrium method (LEM) is commonly used for slope design and stability analysis because it is easy to simulate slope and requires short calculating time. However, LEM cannot adequately simulate ploughing failure in a footwall slope with a joint set dipping parallel with slope, e.g. bedding joint set. This study performed parametric study to analyze the influence factors on ploughing failure using UDEC which is a commercial two-dimensional DEM (Distinct Element Method)-based numerical program. The influence of joint structure and properties on stability of a footwall slope against ploughing failure was investigated, and the factor of safety was estimated using the shear strength reduction method. It was found that the stability of footwall slope against ploughing failure strongly relies on dip angle of conjugate joint, and the critical bedding joint spacing and the critical length of slab triggering ploughing failure are also affected by dip angle of conjugate joint. The results obtained from this study can be used for effective slope design and construction including reinforcement.

• The Journal of the Acoustical Society of Korea
• /
• v.34 no.3
• /
• pp.210-218
• /
• 2015

When the driving voltage of an ultrasound transducer is increased to improve the quality of ultrasound images, heat is generated inside the transducer that can cause patient's skin burn and degradation of transducer performance. Hence, in this paper, a method to disperse the heat of the transducer has been studied. The phased array transducer having 3 MHz center frequency and 32 channels was selected for analyses of the thermal dispersion. First, mechanism of the heat generation was investigated in relation to the transducer operation through theoretical analysis, and material damping and sound pressure amplitude were confirmed to be influential on the heat generation. Further, we investigated the effects of the properties of the materials constituting the transducer on the thermal dispersion through finite element analysis. Based on the analysis results, we determined the thermal properties of the constituent materials that could facilitate the thermal dispersion inside the transducer. The determined thermal properties were applied to the finite element model, and the results showed that the maximum temperature at an acoustic lens contacting with a patient was decreased to 51 % of its initial value.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.1431-1437
• /
• 2008

The small-strain shear modulus ($G_{max}$) of uncemented sand is affected by the the mean principal stress and void ratio, and it has been known that the cementation and aging also affect to $G_{max}$ of sand. For extensive understanding about the effect of cementation on the $G_{max}$ of sand, a series of bender element tests was conducted on the cemented specimens prepared in a large calibration chamber by pluviation of the sand-gypsum mixture. It was observed from the experimental results that the $G_{max}$ of cemented sand is higher above 10 times than value of uncemented one, and it increases exponentially with the gypsum content increases. Whereas, the increase of the vertical stress from 50kPa to 200kPa and the relative density from 40% to 80% result in 20~30% and 2 times increase of $G_{max}$, respectively. It means that the gypsum content, that is cementation level, is the most influential factor on the $G_{max}$ of cemented sand. In addition, the effect of relative density on $G_{max}$ was more apparent on cemented sand than uncemented one.

• Journal of Ocean Engineering and Technology
• /
• v.24 no.6
• /
• pp.61-70
• /
• 2010

This study presents free vibration analyses of perforates steel plates with various cutouts. Four different parameters (shape, size, curvature radius ratio, and rotation of cutouts) were considered to investigate the effects of those parameters on the free vibration characteristics, such as natural frequencies of the perforated steel plates. Three different shapes of cutouts are circle, square, and triangle, and the considered sizes are 5, 10, 15, 20, and 25 mm. For the triangular and square cutouts, the characteristic radii of the inscribed circles of those cutouts were defined. In addition, the curvature radius ratio was defined as the ratio of curvature radius of bluntness and the characteristic radius. Then, total seven different curvature radius ratios (0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1) were considered. To investigate the rotation effect of the cutouts, it was considered four rotations ($0^{\circ}$, $15^{\circ}$, $30^{\circ}$, and $45^{\circ}$) for the square cutouts and three rotations (0, 15, and 30) for the triangular cutouts. All the free vibration analyses were conducted using a general purpose finite element program. From the analyses we found that the most influential parameter for the free vibration response of the perforated plates is the size of cutout. The other factors such as the shape, curvature radius ratio, and rotation are minors; they mainly change the natural frequency as long as the size effect is accompanied.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.32 no.11
• /
• pp.1782-1791
• /
• 2008

The purpose of this study was to find out the hair style image about variations of hair design elements. The method of this study was quasi-experimentation. The twelve color photographs of manikins with various hair style were used as the stimulus. As measuring instrument, a likert scale composed of 35 items of five point adjectives was used. The sample consisted of 157 males and 140 females residing in the Busan area. The range of the age is from 20 to 55. The survey was conducted from August to September in 2007. The data were analyzed by factor analysis, frequency, crosstabs one-way analysis of variance, Duncan's test and t-test used SPSS Packages. The results of this study were as follows: 1. As a result of factor analysis, 8 factors - romantic, natural, elegant, simple, classic, casual, modem and mannish were found out as constructing factors of hairstyle image. 2. As a result of hair style image analysis about variations of hair-length, The short hair style was perceived in modern, mannish, casual, sophisticate, medurm-length style in classic and elegant, long hair style was perceived to be high in romantic and natural. 3. As a result of hair style image analysis about variations of hair design elements, The length of hair style was the most influential element in hair design and secondly important one was the wave of hair style. The color of hair style didn't critical effect on image of hair style.