• Asian Journal of Turfgrass Science
• /
• v.18 no.2
• /
• pp.77-95
• /
• 2004

This study was conducted to find out definition, specification and characteristics of water-proof method for pond at golf courses that located in the mountain in Korea. Water-proof method of pond was selected by location, kind of soil, area, depth, cost, construction period and so on. 1. Soil Bentonite Sealing Liner(SBL) is to mix soil with a good quality bentonite. Then the mixed material was dressed on the bottom of pond. $\\$Merit of SBL is to purify the water and planting is possible. It can also reduce construction period and is economical. It's easy to find out the leak points. Demerit of SBL is expensive, if good quality soil is not in constructing site. Shape of pond edge is simple. 2. Ethylen Propylene Diene Monomer Sheef(EPDM-Sheet) makes use of sheet that resists to acid and alkaline. EPDM-Sheet spreads out as a mat on the pond for water-proof. Merit of EPDM-Sheet is to perfectly prove water and make a diverse shape of pond edge. Demerit of EPDM-Sheet is not friendly to environment. It needs drain system, air ventilation and long period of construction. It is also difficult to find out leaking points in this method. 3. Water proof of ESS-13 uses ESS-13 that is resin of vegetable matter and friendly to environment. To prove water of pond, ESS-13 is delicate with water in the pond. After that, Ess-13 in the water is expanded at pore space in the soil and cover with soil. ESS-13 can be to prove a leaking pond in golf course under business. ESS-13 is cheap and it needs short construction period. It does not need to switch the old water-proof system, additionally. It needs to move fishes to other place before utilizing ESS-13.

• Korean Journal of Radiology
• /
• v.23 no.7
• /
• pp.752-762
• /
• 2022

Objective: To compare a deep learning-based reconstruction (DLR) algorithm for pediatric abdominopelvic computed tomography (CT) with filtered back projection (FBP) and iterative reconstruction (IR) algorithms. Materials and Methods: Post-contrast abdominopelvic CT scans obtained from 120 pediatric patients (mean age ± standard deviation, 8.7 ± 5.2 years; 60 males) between May 2020 and October 2020 were evaluated in this retrospective study. Images were reconstructed using FBP, a hybrid IR algorithm (ASiR-V) with blending factors of 50% and 100% (AV50 and AV100, respectively), and a DLR algorithm (TrueFidelity) with three strength levels (low, medium, and high). Noise power spectrum (NPS) and edge rise distance (ERD) were used to evaluate noise characteristics and spatial resolution, respectively. Image noise, edge definition, overall image quality, lesion detectability and conspicuity, and artifacts were qualitatively scored by two pediatric radiologists, and the scores of the two reviewers were averaged. A repeated-measures analysis of variance followed by the Bonferroni post-hoc test was used to compare NPS and ERD among the six reconstruction methods. The Friedman rank sum test followed by the Nemenyi-Wilcoxon-Wilcox all-pairs test was used to compare the results of the qualitative visual analysis among the six reconstruction methods. Results: The NPS noise magnitude of AV100 was significantly lower than that of the DLR, whereas the NPS peak of AV100 was significantly higher than that of the high- and medium-strength DLR (p < 0.001). The NPS average spatial frequencies were higher for DLR than for ASiR-V (p < 0.001). ERD was shorter with DLR than with ASiR-V and FBP (p < 0.001). Qualitative visual analysis revealed better overall image quality with high-strength DLR than with ASiR-V (p < 0.001). Conclusion: For pediatric abdominopelvic CT, the DLR algorithm may provide improved noise characteristics and better spatial resolution than the hybrid IR algorithm.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.11
• /
• pp.981-986
• /
• 2014

Printed electronics devices are made of several sets of printed patterns. The quality or printability of the printed patterns determines the electrical performance of such devices. Moreover, control of the printability determines the reliability of such devices. Despite its importance, few studies have been reported for the measurement of the printed patterns to evaluate their printability. In this study, a measurement method is proposed for printed patterns, including the definition of the properties to be measured, and the related software is described. The proposed method measures the width, pinholes, and edge waviness and evaluates the printability of the patterns quantitatively. The proposed measurement method could be an efficient tool to evaluate and enhance the printability of printed patterns in printed electronics.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.3
• /
• pp.430-438
• /
• 1997

Deburring and edge finishing technology as the final process of machining operation is required for manufacturing of advanced precise conponents. But, deburring is considered as a difficult problem on going to the high efficient production and automation in the FMS. Removal of burr couldn't have a standard of its definition because of its various shapes, dimensions and properties and mostly depends on manual treatment. Especially, deburring for cross hole inside is very difficult owing to its shape passing through out perpendicular to a main hole. The electrochemical method is suggested as its solution in practical aspect. Therefore, electrochemical deburring technology needs to be developed for the high efficiency and automation of internal deburring in the cross hole. In this study, the new process in the eliminating burr inside cross hole, electrochemical deburring by the wheel electroplated with Cubic-Boron-Nitrade abrasives, is suggested. Its deburring mechanism is described and machining performances is investigated. Also, CBN electroplated wheel is designed and manufactured and then characteristics of electrochemical deburring are investigated through experiments. Overall electrochemical deburring performance against burr inside cross hole is examined in the various power sources such as peak current and direct current.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.5
• /
• pp.1155-1171
• /
• 1996

In this paper, we have analized the characteristics of pseudomedian filter based on the preceding study. The proposed pseudomedian filter methods consist of two types, that are H-shaped and Asterisk-shaped window types. At first, the definition of pseudomedian filter and its algorithm for de-interlacing scan conversion have been descibed, especially its charateristics, this, is the edge preserving characteristics and the required computation have been compared with the conventional algorithms. And PSNR has been introduced to evaluate the pseudomedian filter methods and the conventional algorithms. Finally, it has been discussed on the features and trade off of the pseudomedian filter methods. And the merit and application fields of the pseudomedian filter methods have been discussed.

• Journal of the Korean Mathematical Society
• /
• v.49 no.1
• /
• pp.85-98
• /
• 2012

Let R be a commutative ring and I its proper ideal, let S(I) be the set of all elements of R that are not prime to I. Here we introduce and study the total graph of a commutative ring R with respect to proper ideal I, denoted by T(${\Gamma}_I(R)$). It is the (undirected) graph with all elements of R as vertices, and for distinct x, y ${\in}$ R, the vertices x and y are adjacent if and only if x + y ${\in}$ S(I). The total graph of a commutative ring, that denoted by T(${\Gamma}(R)$), is the graph where the vertices are all elements of R and where there is an undirected edge between two distinct vertices x and y if and only if x + y ${\in}$ Z(R) which is due to Anderson and Badawi [2]. In the case I = {0}, $T({\Gamma}_I(R))=T({\Gamma}(R))$; this is an important result on the definition.

• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.4
• /
• pp.61-68
• /
• 2008

Of the seven base units of the international system of units, only the kilogram is still defined in terms of a material artifact. One of the experimental approaches opening the way to a new definition of the kilogram is the watt balance To improve the performance of the NPL watt balance, we need to quantify and reduce hysteresis effects in the balance knives. In this paper, we discuss the mechanical characteristics of the knife edges used in the NPL watt balance. The hysteresis mechanism is analyzed using the finite element method. It is found that the cause of hysteresis is not normal stress but shear, and the deformation of the flat, rather than the knife, is an important factor in the hysteresis mechanism. The study presented here, using finite element analysis, suggests that parameters such as material property, tip radius and knife straightness can be more important than others, such as friction coefficient, tip angle, etc.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.11C
• /
• pp.1152-1160
• /
• 2003

Start The current paper proposes an improved HD(High Definition) monitor that can support a signal input with various resolutions. Due to the inadequate performance of the built-in digital PLL(Phase-locked Loop) of an ADC(Analog to Digital Converter) and poor tolerance of ADC ICs, there are problems in the stable processing of synchronization signals with various input signals. Accordingly, the proposed synchronization signal optimization technique regenerates the horizontal synchronization signal in the vertical blanking interval based on the regularity of the synchronization signal, i.e. the timing of the falling edge signal remains constant, thereby solving the above problem and minimizing the interference of the system. As a result, the proposed system can stabilize various synchronization signals with different resolution modes.

• Journal of the Semiconductor & Display Technology
• /
• v.15 no.2
• /
• pp.61-65
• /
• 2016

Facial feature detection is a fundamental function in the field of computer vision such as security, bio-metrics, 3D modeling, and face recognition. There are many algorithms for the function, active shape model is one of the most popular local texture models. This paper addresses issues related to face detection, and implements an efficient extraction algorithm for extracting the facial feature points to use on iOS platform. In this paper, we extend the original ASM algorithm to improve its performance by four modifications. First, to detect a face and to initialize the shape model, we apply a face detection API provided from iOS CoreImage framework. Second, we construct a weighted local structure model for landmarks to utilize the edge points of the face contour. Third, we build a modified model definition and fitting more landmarks than the classical ASM. And last, we extend and build two-dimensional profile model for detecting faces within input images. The proposed algorithm is evaluated on experimental test set containing over 500 face images, and found to successfully extract facial feature points, clearly outperforming the original ASM.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.2
• /
• pp.149-157
• /
• 2004

Implicit finite element analysis of the flat surface-straight edge hemming process is performed by using a commercial code ABAQUS/Standard. Methods of finite element modeling for springback simulation and contact pair definition are discussed. An optimal mesh system is chosen through the error analysis that is based on the smoothing of discontinuity in the state variables. This study has focused on the investigation of the influence of process parameters in flanging, pre-hemming and main hemming on final hem quality, which can be defined by turn-down, warp and roll-in. The parameters adopted in this parametric study are flange length, flange angle, flanging die corner radius, face angle and insertion angle of pre-hemming punch, and over-stroke of pre-hemming and main hemming punches.