• Geomechanics and Engineering
• /
• v.17 no.3
• /
• pp.279-285
• /
• 2019

The process of slope stability analysis is one of the most important stages in design of some civil and mining projects. Bimslopes are made from bimrocks (block-in-matrix rocks) where rocky blocks are distributed in a bonded matrix of finer texture. These kind of slopes are often seen in weathered and near-surface depths. Previous studies have shown that VBP (Volumetric Block Proportion) is one of the most significant factors affecting bimrocks strength and consequently the stability of bimslopes. In this paper, the influence of block inclinations on bimslope stability have been investigated. For this purpose, 180 theoretical models have been made with various VBPs, all of them have a specified block size distribution. These bimslopes contain blocks with differing dips relative the slope inclination. Also for each kind of block inclination, 10 different blocks arrangements have been modeled. The Finite Element Method (FEM) was used to analysis the stability of these bimslopes models. The results showed the inclination of blocks has a strong impact on the Safety Factor and stability of bimslopes. When the difference in angle of dip of blocks relative to the slope angle is maximum, the Safety Factor of bimslopes tends to be a maximum compared with the matrix-only state. Furthermore, with increasing VBP of bimslopes stability increases. The graphs obtained from this study could be used for preliminary guidance in the projects design with bimslopes.

• Journal of the Architectural Institute of Korea Structure & Construction
• /
• v.34 no.1
• /
• pp.11-18
• /
• 2018

An experimental study on the ultimate behaviors of the mild carbon steel (SPHC) fillet-welded connection is presented in this paper. Seven specimens were fabricated by the shielded metal arc welding (SMAW). All specimens failed by typical block shear fracture in the base metal of welded connections not weld metal. Block shear fracture observed in the base metal of welded connection is a combination of single tensile fracture transverse to the loading direction and two shear fractures longitudinal to the loading direction. Test strengths were compared with strength predictions by the current design equations and suggested equations by previous researchers. It is known that current design specifications (AISC2010 and KBC2016) and Oosterhof & Driver's equation underestimated overly the ultimate strength of the welded connection by on average 44%, 31%, respectively and prediction by Topkaya's equation was the closest to the test results. Consequently, modified equation is required to be proposed considering the stress triaxiality effect and material property difference on the block shear strength for base metal fracture in welded connections fabricated with mild carbon steel.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.1
• /
• pp.97-119
• /
• 2023

The number of industrial Internet of Things (IoT) users is increasing rapidly. Lightweight block ciphers have started to be used to protect the privacy of users. Hardware-oriented security design should fully consider the use of fewer hardware devices when the function is fully realized. Thus, this paper designs a lightweight block cipher IIoTBC for industrial IoT security. IIoTBC system structure is variable and flexibly adapts to nodes with different security requirements. This paper proposes a 4×4 S-box that achieves a good balance between area overhead and cryptographic properties. In addition, this paper proposes a preprocessing method for 4×4 S-box logic gate expressions, which makes it easier to obtain better area, running time, and power data in ASIC implementation. Applying it to 14 classic lightweight block cipher S-boxes, the results show that is feasible. A series of performance tests and security evaluations were performed on the IIoTBC. As shown by experiments and data comparisons, IIoTBC is compact and secure in industrial IoT sensor nodes. Finally, IIoTBC has been implemented on a temperature state acquisition platform to simulate encrypted transmission of temperature in an industrial environment.

• The Korean Journal of Applied Statistics
• /
• v.25 no.5
• /
• pp.847-857
• /
• 2012

This article is concerned with choice-based conjoint analysis versus rating-based and ranking-based conjoint analysis. Choice-based conjoint analysis has a definite advantage in that the respondent's task of choosing the most preferred profile from several competing profiles adequately mimics consumer marketplace behavior. It is crucial to design the choice sets appropriate for the choice-based conjoint. Thus, this article suggests a new method to design the choice sets that are well-balanced. It augments the balanced incomplete block design and then obtains the dual design of the result to accommodate various numbers of profiles. In consequence, the choice sets designed by the new method have the desirable characteristics that each profile is presented to the same number of respondents, and pairs of any two distinct profiles occur together in the same number of choice sets. The balancing of the design increases the efficiency of the conjoint analysis. In addition, the pair-comparison scheme can improve the quality of data through the identification of contradictory responses.

• Journal of the Microelectronics and Packaging Society
• /
• v.24 no.4
• /
• pp.91-95
• /
• 2017

Package-On-Package (PoP) technology is developing toward smaller form factors with high-speed data transfer capabilities to cope with high DDR4x memory capacity. The common application processor (AP) used for PoP devices in smartphones has the bottom package as logic and the top package as memory, which requires both thermally and electrically enhanced functions. Therefore, it is imperative that PoP designs consider both thermal and power distribution network (PDN) issues. Stacked packages have poorer thermal dissipation than single packages. Since the bottom package usually has higher power consumption than the top package, the bottom package impacts the thermal budget of the top package (memory). This paper investigates the thermal and electrical characteristics of PoP designs, particularly the bottom package. Findings include that via and dense via-cluster volume have an important role to lower thermal resistance to the motherboard, which can be an effective way to manage chip hot spots and reduce the thermal impact on the memory package. A Cu block and dense via-cluster layout with an optimal location are proposed to drain the heat from the chip hot spots to motherboard which will enhance thermal and electrical performance at the design stage. The analytical thermal results can be used for design guidelines in 3D packaging.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.10a
• /
• pp.143-149
• /
• 2009

Recently, according to the tendency to the more comfortable automobile, the improvement of performance of the cooling fan is required. The performance of cooling fan is affected by many peripheral parts, such as radiator, condenser, engine block and etc. Therefore, it is important to consider the effect of peripheral components on the fan performance in design and analysis stages. In this paper, the performance of automobile cooling fan is investigated experimentally by using the large capacity fan tester based on the ASHRAE and the AMCA standards. In particular, the various spacing between cooling fan and engine block are considered to obtain the effect of engine block. An empirical relation between the fan flow rate and the spacing was proposed.

• Proceedings of the KSME Conference
• /
• 2001.06c
• /
• pp.219-223
• /
• 2001

This paper introduces DS/Block-Structure - a structural analysis module of DS/Block, which is a Design System to simulate the behavior of a ship block in various crane operations and to evaluate its structural deformation using the finite element method. It runs based on a CAD program, Pro/ENGINEER, and structural analyses are performed by a developed FE code. Boundary conditions for the FE analysis of a ship block under lifting and turnover operation are also considered.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.10a
• /
• pp.639-648
• /
• 2005

Up to now, practical engineers applying simplicity value of rockfall block weight suggested in design manual without considering in-situ rockfall block weight which reflect joint characteristics. However, the size of rockfall block varies with joint spacing of discontinuities and influences over rockfall analysis results. In this paper, we estimate realistic rockfall block weight distribution using statistical invariances of joint spacing derived from scan-line survey result. And, we study whether this distribution is applicable in practical rockfall analysis directly. As the results of this study, rockfall analysis results that using rockfall block weight distribution estimated from scan-line survey show resonable and realistic outcomes.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.51 no.4
• /
• pp.137-143
• /
• 2002

Because Block Pulse functions are used in a variety of fields such as the analysis and controller design of systems, it is necessary to find the more exact value of the Block Pulse series coefficients. This paper presents a method for the state estimation of the time-invariant linear systems via the improved estimation method for the Block Pulse coefficients by using the Simpson's rule. The proposed method using the Simpson's rule improve the accuracy of the Block Pulse coefficients.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.1
• /
• pp.76-81
• /
• 2018

This study aims to provide ways to achieve structural improvements of the internal flow path of the discharge plenum of a swash plate piston pump valve block vulnerable to cracks. This paper corresponds to Part II, which consists of a structural interpretation of the internal flow path of the discharge plenum of the valve block. The simple model result reviewed in Part I was incorporated into the valve block model and five different design changes were reviewed as part of the study on the structural improvement of the internal flow path of the valve block.