• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2721-2731
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• 1997

Distributed programming can be greatly simplified by language support for distributed communication. Many web-browsers now offer some form of active objects and the number and types of them are growing daily in interesting and innovative ways. Java applets are well known as one kind of active object related to web-browser. This paper focuses in distributed active objects which is one kind of active objects that can communicate with other active objects located in different machines across the Internet. Java RMI and CORBA IDL are two major programming environments for distributed active objects which are non compatible with each other. To make discussion concrete, we introduce a single application as implemented on two environments : the HORM, adopting RMI mechanism, and the OrbixWeb2.0.1, adopting CORBA specification, respectively. Binding, inheritance, polymorphism, object passing and callbacks across the machine boundary in distributed programming environments are issued. The results show that some differences in the implementation of distributed active objects can have a significant impact on how distributed applications are structured. The comparison between two implementations on the programming environments will be the basis for building the translation system between HORB to OrbixWeb and vice versa.

• Geomechanics and Engineering
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• v.31 no.5
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• pp.477-488
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• 2022

Pile composite foundation (PCF) has been commonly applied in practice. Existing research has focused primarily on semi-infinite media having equal pile lengths with little attention given to the effects of inclined bedrock and dissimilar pile lengths. This investigation considers the effects of inclined bedrock on vertical loaded PCF with dissimilar pile lengths. The pile-soil system is decomposed into fictitious piles and extended soil. The Fredholm integral equation about the axial force along fictitious piles is then established based on the compatibility of axial strain between fictitious piles and extended soil. Then, an iterative procedure is induced to calculate the PCF characteristics with a rigid cap. The results agree well with two field load tests of a single pile and numerical simulation case. The settlement and load transfer behaviors of dissimilar 3-pile PCFs and the effects of inclined bedrock are analyzed, which shows that the embedded depth of the inclined bedrock significantly affects the pile-soil load sharing ratios, non-dimensional vertical stiffness N₀/wdE_s, and differential settlement for different length-diameter ratios of the pile l/d and pile-soil stiffness ratio k conditions. The differential settlement and pile-soil load sharing ratios are also influenced by the inclined angle of the bedrock for different k and l/d. The developed model helps better understand the PCF characteristics over inclined bedrock under vertical loading.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.246-250
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• 2008

This paper presents the design of network vulnerability analysis system which can integrate various vulnerability assessment tools to improve the preciseness of the vulnerability scan result. Manual checking method performed by a security expert is the most precise and safe way. But this is not appropriate for the large-scale network which has a lot of systems and network devices. Therefore automatic scanning tool is recommended for fast and convenient use. The scanning targets may be different according to the kind of vulnerability scanners, or otherwise even for the same scanning target, the scanning items and the scanning results may be different by each vulnerability scanner, Accordingly, there are the cases in which various scanners, instead of a single scanner, are simultaneously utilized with the purpose of complementing each other. However, in the case of simultaneously utilizing various scanners on the large-scale network, the integrative analysis and relevance analysis on vulnerability information by a security manager becomes time-consumable or impossible. The network vulnerability analysis system suggested in this paper provides interface which allows various vulnerability assessment tools to easily be integrated, common policy which can be applied for various tools at the same time, and automated integrative process.

• Journal of the Korean earth science society
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• v.40 no.2
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• pp.177-187
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• 2019

Several volcanic activities have continued in Mt. Baekdu since the Millennium eruption, and these phenomena have increased the need for volcanic activity surveillance. Various geophysical approaches are needed to obtain the depth and size of magma chamber that lie several kilometers below the surface. We examined the applicability of direct-current resistivity survey in this study. In order to explore the deep magma chamber of Mt. Baekdu, which has a spatial limitation due to the borderline, a large-scale survey with a length of tens of kilometers should be conducted. This type of survey requires a distributed measurement system and optimized exploration designs. Therefore, we propose survey designs taking advantage of our developed distributed acquisition system and analyze the applicability using numerical simulation. We confirmed that our designs that use single survey line with offline transmitting points show comparable results to the conventional 3D survey. It is expected that our research result can contribute to the deep geophysical exploration in Mt. Baekdu.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.2
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• pp.174-182
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• 2002

The object-oriented design methods and their CASE tools are widely used in practice by many real-time software developers. However, object-oriented CASE tools require an additional step of identifying tasks from a given design model. Unfortunately, it is difficult to automate this step for a couple of reasons: (1) there are inherent discrepancies between objects and tasks; and (2) it is hard to derive tasks while maximizing real-time schedulability since this problem makes a non-trivial optimization problem. As a result, in practical object-oriented CASE tools, task identification is usually performed in an ad-hoc manner using hints provided by human designers. In this paper, we present a systematic, schedulability-aware approach that can help mapping real-time object-oriented models to multi-threaded implementations. In our approach, a task contains a group of mutually exclusive transactions that may possess different periods and deadline. For this new task model, we provide a new schedulability analysis algorithm. We also show how the run-time system is implemented and how executable code is generated in our frame work. We have performed a case study. It shows the difficulty of task derivation problem and the utility of the automated synthesis of implementations as well as the Inappropriateness of the single-threaded implementations.

• Wind and Structures
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• v.38 no.1
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• pp.15-42
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• 2024

A flexible-base coupled-two-beam (CTB) discrete model with equivalent tuned mass dampers is used to assess the effect of soil-structure interaction (SSI) and different types of lateral resisting systems on the design of passive dynamic absorbers (PDAs) under the action of along-wind and across-wind loads due to vortex shedding. A total of five different PDAs are considered in this study: (1) tuned mass damper (TMD), (2) circular tuned sloshing damper (C-TSD), (3) rectangular tuned sloshing damper (R-TSD), (4) two-way liquid damper (TWLD) and (5) pendulum tuned mass damper (PTMD). By modifying the non-dimensional lateral stiffness ratio, the CTB model can consider lateral deformations varying from those of a flexural cantilever beam to those of a shear cantilever beam. The Monte Carlo simulation method was used to generate along-wind and across-wind loads correlated along the height of a real shear wall-frame building, which has similar fundamental periods of vibration and different modes of lateral deformation in the xz and yz planes, respectively. Ambient vibration tests were conducted on the building to identify its real lateral behavior and thus choose the most suitable parameters for the CTB model. Both alongwind and across-wind responses of the 144-meter-tall building were computed considering four soil types (hard rock, dense soil, stiff soil and soft soil) and a single PDA on its top, that is, 96 time-history analyses were carried out to assess the effect of SSI and lateral resisting system on the PDAs design. Based on the parametric analyses, the response significantly increases as the soil flexibility increases for both type of lateral wind loads, particularly for flexural-type deformations. The results show a great effectiveness of PDAs in controlling across-wind peak displacements and both along-wind and across-wind RMS accelerations, on the contrary, PDAs were ineffective in controlling along-wind peak displacements on all soil types and different kind of lateral deformation. Generally speaking, the maximum possible value of the PDA mass efficiency index increases as the soil flexibility increases, on the contrary, it decreases as the non-dimensional lateral stiffness ratio of the building increases; therefore, there is a significant increase of the vibration control effectiveness of PDAs for lateral flexural-type deformations on soft soils.

• Korean Journal of Human Ecology
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• v.19 no.1
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• pp.149-156
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• 2010

TV news anchor woman's appearance, voice, expression, and clothing, etc., have an influence on the reliability of the article to be reported. Among these, clothing is the most crucial factor in forming an anchor woman's image, especially the clothing color factor. This study is aimed at providing the basic foundation for anchor woman when they select the clothing color by analyzing the clothing color image on the screen. For this purpose, the KBS and MBC 9 o'clock news desk and SBS 8 o'clock news of the local major news programs were selected. With the collection of 300 pieces of news clips related to anchor woman's clothing from January to December 2008, they were classified into F/W seasons and analyzed by the clothing color. The surveying method of clothing color was to capture the anchor woman's clothing among the news clips, then pick the representing color by applying Adobe Photoshop, and researching the formed $L^*a^*b^*$ value of color chips. The surveyed color was transformed into value of distant cell, H V/C, and the results were analyzed. As a result, it showed that the White system for anchor woman's clothing during the S/S seasons is most frequently picked, followed by the Red system. In F/W seasons, Gray system is the most favored, then White and Red, respectively. It was revealed that the most frequently selected colors for upper-wear by anchor women in the three broadcasting stations was an achromatic color, such as White or Gray, and then the chromatic color, Red. It shows that there is no big difference in season. The Inner-wear color matched the jackets which were also achromatic in color, white and black being the most favored in the S/S seasons, and in the case of chromatic colors, Red was the most favored. In addition to this, identical coloration with jacket, coloration with similar color, or single color as clothing color were no less frequently adopted. During the F/W seasons, identical coloration accounts for 26%, the most popular colored being White and Red. It was found that the coloration with achromatic colors are highly favored in the three major broadcasting stations alike.

• Journal of Biomedical Engineering Research
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• v.18 no.3
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• pp.291-299
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• 1997

As a microimaging device detecting gamma rays emitted from small lesions or tumors during operation, the intraoperative surgical probe has been proposed and is now under development. We have designed a multipurpose portable gamma prove system and evaluated the performance both for the absolute counting purpose of residual radioactivities and for the localizing capability of gamma events using the NaI(Tl) crystal and two types of photomultiplier tubes(PMTs). Counting efficiencies in the range of routine clinical use of radiation dose were measured using the assembly of single channel PMTs and 0.5 inch thick NaI(Tl) crystal of 1 inch diameter. The positioning of gamma events for imaging purpose requires the multiple channel PMTs with appropriate positioning electronics. We have designed a simple and reliable positioning circuit based on the concept of modified Anger. In preliminary experiments using the multiple channel PMT of 3 inch diameter and the dim lighth source, we were able to trace and localize the correct position with reduced positioning error by the use of two multiplier/divider chipset and simplified peripherals. The energy resolutions for the counting gamma probe measured as full width at half maximum(FWHM) for Cs-137, F-18, Tc-99m were 12%, 13%, and 36%, respectively. The spatial resolution for the imaging gamma probe measured as FWHM for green LED was 2.9 mm. The results indicate that the currently developing probe is very promising and could be very useful for many applications in nuclear medicine. Future studies will include developing collimators, improving interface hardwares, and evaluating the system with clinical data.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.8
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• pp.171-180
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• 2020

Smart Factory consists of digital automation solutions throughout the production process, including design, development, manufacturing and distribution, and it is an intelligent factory that installs IoT in its internal facilities and machines to collect process data in real time and analyze them so that it can control itself. The smart factory's equipment works in a physical combination of numerous hardware, rather than a virtual character being driven by a single object, such as a game. In other words, for a specific common goal, multiple devices must perform individual actions simultaneously. By taking advantage of the smart factory, which can collect process data in real time, if reinforcement learning is used instead of general machine learning, behavior control can be performed without the required training data. However, in the real world, it is impossible to learn more than tens of millions of iterations due to physical wear and time. Thus, this paper uses simulators to develop grid sortation systems focusing on transport facilities, one of the complex environments in smart factory field, and design cooperative multi-agent-based reinforcement learning to demonstrate efficient behavior control.

• Journal of agriculture & life science
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• v.50 no.3
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• pp.31-41
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• 2016

This study was conducted to develop a handy earth auger for use in sloppy and rugged forest terrains in order to reduce labor cost which comprises a major part of the production costs in forest afforestation projects. The first prototype is developed consist of two parts, the soil-digging screw and the battery power source. The specifications of the first prototype screw are: length of 170mm, a top diameter of 60mm, bottom diameter of 47mm, 23° angle for each helix, and a 50mm awl-head tip. The use of a single line of screw was selected for reduced weight. In addition, a power source of rotary DC Motor(WD-6G2425, WONILL, Korea) with a maximum torque of 30kgf-cm, rotation of 20-30rpm, K6G30C decelerator with a reduction ratio of 30:1 which could be used with no load for 48 was operated. In consideration of its weight, a lithium battery was utilized in line with the goal of developing a lightweight auger. In order to evaluate the performance of the first prototype, test sites were selected as 6 areas. The rotational force was found to be highest in area A(Solid area), followed by areas F(Mounted slope 40° area) and E(Mounted slope 30° area). It was also observed that in general, the rotational force increased along with the increase in soil depth with the maximum rotational force recorded at 10cm.