• Journal of the Korean Geosynthetics Society
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• v.4 no.2
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• pp.11-18
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• 2005

A pilot scale filed model test and 2-D numerical analysis was conducted to evaluate the effectiveness of constructing a geogrid-reinforced and pile-supported embankment system over soft ground to reduce differential settlement, and the results are presented hearin. Three-by-three pile groups with varying the space between pile were driven into a layer of soft marine clay and a layer of geogrid was used as reinforcement over each pile group. 2-D numerical analysis has been conducted by using the FLAC-2D(Fast Lagrangian Analysis of Continua) program for same condition of field model test. The settlement, vertical stress, and strain of geogrid due to the construction of embankment were measured at various locations. Based on the field model test and numerical analysis results, pile reinforcement generated the soil arching at the midspan of pile cap and the geogrid reinforcement helps reduce the differential settlement of the soft ground by tensile strength of geogrid. Also for $D/b{\geq}6.0$, the effectiveness of geogrid reinforcement in reducing settlement is negligible.

• Journal of Korea Spatial Information System Society
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• v.6 no.2 s.12
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• pp.63-75
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• 2004

This paper proposes a Web Service framework on both wired and wireless network environment that can be interoperable and extensible among geo-spatial servers. Mostly, OGC has studied and announced international standards which are related to web services on various kinds of geo-spatial data. Therefore, the proposed framework satisfies interoperability and extensibility for geo-spatial servers by adapting WMS, WFS, WCS, and WRS standards of OGC and web services standards of W3C. This framework, also, satisfies requirements of huge volumed data service, GML service, geo-spatial function service, and wireless network service. This framework consists of geo-spatial servers group, geo-spatial broker, and web-based client. The geo-spatial servers group includes GIS, SIIS, ITS, GNSS, and Telematics server for the purpose of providing various kinds of geo-spatial services. Especially, this paper proposes main memory based GIS server(MMG server) that can efficiently serve huge volumed GML data on wireless network environment. Finally, experimental results about the MMG server and prototype implementations of the framework show the effectiveness of this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3587-3593
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• 2009

Nowadays, the PV systems have been focused on the interconnection between the power source and the grid. The PV inverter, either single-phase or three-phase, can be considered as the core of the whole system because of an important role in the grid-interconnecting operation. An important issue in the inverter control is the load current regulation. In the literature, the Proportional+Integral (PI) controller, normally used in the current-controlled Voltage Source Inverter (VSI), cannot be a satisfactory controller for an ac system because of the steady-sate error and the poor disturbance rejection, especially in high-frequency range. By comparison with the PI controller, the Proportional+Resonant (PR) controller can introduce an infinite gain at the fundamental ac frequency; hence can achieve the zero steady-state error without requiring the complex transformation and the dq-coupling technique. In this paper, a PR controller is designed and adopted for replacing the PI controller. Based on the theoretical analyses, the PR controller based control strategy is implemented in a 32-bit fixed-point TMS320F2812 DSP and evaluated in a 3kW experimental prototype Photovoltaic (PV) power conditioning system (PCS). Simulation and experimental results are shown to verify the performance of implemented control scheme in PV PCS.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.21 no.3
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• pp.97-106
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• 2015

Thermal deformation of packaging materials was observed in some ready-to-eat food products for microwave use. Therefore, the deformation patterns depending on packaging types and shapes of 9 domestic and 11 foreign products after microwave heating were investigated. Among the domestic and foreign products, thermal deformations of packaging material were observed in 5 and 8 samples, respectively. Besides, thermal deformation occurred on the lid and cup body of tray filled with a spicy chicken sauce after having microwaved where previously no deformation had been observed with other food types. No consistent results of thermal deformation were obtained by the analysis of salinity, brix, pH and viscosity of RTE products for microwave heating. However, thermal deformations of packages were less found in the packages used for the RTE foods contained very high or low viscosity than those with medium viscosity. Furthermore, the degree of thermal deformations was dependent on the food composition and shape as well as package type. In order to prevent the thermal deformation of packaging materials, therefore, technological advances and further studies are required to develop the heat-resistant packaging system and to improve the non-uniformity during microwave heating of RTE foods.

• Science of Emotion and Sensibility
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• v.21 no.3
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• pp.165-176
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• 2018

The objective of this study was to develop clothing-type wearable motion sensing and feedback systems to enhance children's sports by promoting visual and audio feedback. In this study, several applications, such as fabric sensors, sportswear integrated with various types of fabric sensors, and fabric-based motion sensing module design, as well as a visual and audio feedback system for gaining a better understanding of a child's interest in a type of exercise, were developed. An SWCNT-based stretchable fabric sensor was developed for motion sensing, and sportswear was designed using the fabric sensor that was integrated into the limbs of the garment. The sensing module was developed, and sensory performance was evaluated through a joint motion experiment for children. In addition, using the feedback system that was developed in the form of an accessory, the responses of light and sound were also examined based on the movement of the child who was wearing the sportswear prototypes. This study focused on the development and assessment of prototype designs for children's sportswear and accessory products that can help to ascertain a child's interest in a particular exercise.

• Journal of Internet Computing and Services
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• v.13 no.3
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• pp.115-126
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• 2012

Mashups have become very popular over the last few years, and their use also varies for IT convergency services. In spite of their popularity, there are several challenging issues when combining Open APIs into mashups, First, since portal sites may have a large number of APIs available for mashups, manually searching and finding compatible APIs can be a tedious and time-consuming task. Second, none of the existing portal sites provides a way to leverage semantic techniques that have been developed to assist users in locating and integrating APIs like those seen in traditional SOAP-based web services. Third, although suitable APIs have been discovered, the integration of these APIs is required for in-depth programming knowledge. To solve these issues, we first show that existing techniques and algorithms used for finding and matching SOAP-based web services can be reused, with only minor changes. Next, we show how the characteristics of APIs can be syntactically defined and semantically described, and how to use the syntactic and semantic descriptions to aid the easy discovery and composition of Open APIs. Finally, we propose a goal-directed interactive approach for the dynamic composition of APIs, where the final mashup is gradually generated by a forward chaining of APIs. At each step, a new API is added to the composition.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.461-477
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• 2017

Organosilicone-based surfactants, consisting of hydrophobic organosilicone groups coupled to hydrophilic polar groups, have been widely used in many industrial fields starting from polyurethane foam to construction materials, cosmetics, paints & inks, agrochemicals, etc., because of their low surface tension, lubricity, spreading, water repellency and thermal and chemical stability, resulted from the unique properties of organosilicone. Especially, organosiloxane surfactants, having low molecular weight siloxane as hydrophobe, exhibit low surface tension and excellent wettability and spreadability, leading to their applications as super wetter/super spreader, but have the disadvantage of vulnerability to hydrolysis. A variety of low molecular weight siloxane surfactant structures are required to provide the functional improvement and the defect resolution for reflecting the necessities in the various applications. This review includes the synthetic schemes of reactive tetrasiloxanes and disiloxanes as hydrophobic siloxane backbones, the main reaction schemes, such as hydrosilylation reaction, for coupling reactive tetrasiloxanes or disiloxanes to hydrophilic groups, and the main synthetic schemes of the tetra- and di-siloxane surfactants having polyether-, carbohydrate-, gemini-, bola-type surfactant structures.

• The Journal of the Korea Contents Association
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• v.9 no.5
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• pp.61-75
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• 2009

Generally, the development of the database application includes the requirement analysis phase of creating ERD (Entity Relationship Diagram) and process models, coding, and testing. From the above phases, the analysis phase is not most formalized. It is usually hard task because (1) customers don't know the details of the desired system; (2) developers can't with ease understand the business logic of the customers; (3) the outcomes of the analysis, which are ERD and process models, are not easy to understand to the customers. This paper propose that the executional forms, which are better to understand the systems, should be presented to the customers instead of the ERD. These forms should accept the data input so that customers can review the various aspects of the outcome models. The developers should be able to instantly implement the business logic and also should be able to visually demonstrate the logic in order to get the details of it. For this goal, the customer supplied business logic should be able to be implemented by the references between forms, actions, constraints from the perspective of the data flow. The customers try to execute the forms implementing the business logic and review their supplied logic find new necessary business logic of their own. Iterating these processes for the requirement analysis would result in the success of the analysis which is sufficiently detailed without conflicts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.89-97
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• 2018

In the past, hospitals were planned with a minimum of public space for the sole purpose of treatment. On the other hand, modern hospitals have more public space as the importance of the healing environment increases and are planned taking into consideration the patients, guardians, and medical staff. In addition, the lobby shape is developed from a HALL type and planned as a STREET type or CONCOURSE type, increasing the public area. Unlike past hospitals, which were used as reception, waiting, and procedure spaces, modern hospitals are used as commercial, hobby, and cultural space. The purpose of the study was to evaluate the healing environment of the hospital lobby based on the shape of the plane surface by deducting the elements of general hospitals' healing environment from preceding studies as a framework. The hospital lobby is an important place where many actions occur. Therefore, 3 types of cases were evaluated based on the plane form. As a result of the study, the STREET type showed a better healing environment than the HALL type, but the accessibility, roof garden, and resting place showed similar results. Because the case was based on a large general hospital, which had sufficient planned space, the factor has little to do with the style of the lobby. Among the STREET types, the linear atrium showed a better result in terms of the sense of space and inflow effect of natural lighting than the four-sided atrium because the linear atrium has large open volume ratio. When the lobby plane is the HALL type, a cross section of the courtyard had a large open volume ratio. Therefore, the shape of the cross section is as important as the plane form of the lobby.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.9-15
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• 2018

The turbochargers, which are used widely in diesel and gasoline engines, are an effective device to reduce fuel consumption and emissions. On the other hand, turbo-lag is one of the main problems of a turbocharger. Bearing friction losses is a major cause of turbo lag and is particularly intense in the lower speed range of the engine. Current turbochargers are mostly equipped with floating bearings: two journal bearings and one thrust bearing. This study focused on the bearing friction at the lower speed range and the experimental equipment was established with a drive-motor, load-cell, magnetic coupling, and oil control system. Finally, the friction losses of turbochargers were measured considering the influence of the rotating speed from 30,000rpm to 90,000rpm, oil temperature from $50^{\circ}C$ to $100^{\circ}C$, and oil supply pressure of 3bar and 4bar. The friction power losses were increased exponentially to 1.6 when the turbocharger speed was increased. Friction torques decreased with increasing oil temperature and increased with increasing oil pressure. Therefore, the oil temperature and pressure must be maintained at appropriate levels.