• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10B
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• pp.1675-1689
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• 2000

We present CReMeS a CORBA-compliant design and implementation of a new real-time communication service. It provides for efficient predictable and scalable communication between information producers and consumers. The CReMeS architecture is based on MidART's Real-Time Channel-based Reflective Memory (RT-CRM) abstraction. This architecture supports the separation of QoS specification between producer and consumer of data and employs a user-level scheduling scheme for communicating real-time tasks. These help us achieve end-to-end predictability and allows our service to scale. The CReMeS architecture provides a CORBA interface to applications and demands no changes to the ORB layer and the language mapping layer. Thus it can run on non real-time Off-The-Shelf ORBs enables applications on these ORBs to have scalable and end-to-end predictable asynchronous communication facility. In addition an application designer can select whether to use an out-of-band channel or the ORB GIOP/IIOP for data communication. This permits a trade-off between performance predictability and reliability. Experimental results demonstrate that our architecture can achieve better performance and predictability than a real-time implementation of the CORBA Even Service when the out-of-band channel is employed for data communication it delivers better predictability with comparable performance when the ORB GIOP/IIOP is used.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.998-1004
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• 2002

This paper reports a design of feedforward linear power amplifier using pilot tone for IMT-2000 band repeaters accepting multi-carrier. As this time pilot tone is applied to the circuit differently from the existing method. Only one pilot tone is used in both 1-st loop(IMD abstraction loop) and 2-nd loop(IMD cancellation loop) to cancell IMD signals automatically according to variation of frequency or power level of input signals. As an experiment, in range of 2110 MHz - 2170 MHz at LPA output power of $20 W_{avg}$, IMD characteristics of over 20 dB was improved maintaining below -60 dBc considering respective 20 MHz. Therefore the supposed feedforward linear power amplifier can be used for linear power amplifier in IMT-2000 band repeaters.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.19-27
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• 2006

This paper presents a query processing model in a wrapper based on the XML view tree. The query processing in a wrapper requires view composition, query translation into local sources, and generation of XML documents from local query results. We present a query processing model based on the view tree, where the XML views and the XML query is represented by the view tree. Since the view tree keeps the structure of a virtual XML document, it is easy to navigate the path expression. The view tree is also used as a template for schema generation and XML document generation as a query result. Moreover this conceptual uniform abstraction for the XML view and the user query makes it easy to support a multi-level XML view and to implement our composition mechanism.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.97-97
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• 2016

Development of advanced Li-ion battery cells with high durability is critical for safe operation, especially in applications to electric vehicles and portable electronic devices. Understanding fundamental mechanism on the formation of a solid-electrolyte interphase (SEI) layer, which plays a substantial role in the electrochemical stability of the Li-ion battery, in a cathode was rarely reported unlike in an anode. Using first-principles density functional theory (DFT) calculations and ab-initio molecular dynamic (AIMD) simulations we demonstrate atomic-level process on the generation of the SEI layer at the interface of a carbonate-based electrolyte and a spinel $LiMn_2O_4$ cathode. To accomplish the object we calculate the energy band alignment between the work function of the cathode and frontier orbitals of the electrolyte. We figure out that a proton abstraction from the carbonate-based electrolyte is a critical step for the initiation of an SEI layer formation. Our results can provide a design concept for stable Li-ion batteries by optimizing electrolytes to form proper SEI layers.

• Korean Institute of Interior Design Journal
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• v.17 no.2
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• pp.39-46
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• 2008

This paper is a research about the expression and characteristics of sense space by a phenomenological approach through body from an anthropocentric point of view. The phenomenological expression elements of sense space have been abstracted by putting the characteristics of body perception into shape through the phenomenological approach. This research aims to provide the expression and characteristics of sense space that can be applied by phenomenological elements of emotional expression, and analyze their application level by phenomenological body perception in space through corresponding examples. As a result of this research, the expressions of sense space approach - such as migration of moving lines, reiteration and segmentation of region, spatial flexibility, transferal of sense, stimulation of combined senses, symbolic abstraction of memory, perception of environment and space, time by light, phenomenal water space, time expression by surrounding environments etc. - and the characteristics of sense space according to each expression have been obtained through the phenomenological expression elements in sense space such as expansive perception by consecutive scenes, spatial and sensory experience, embodiment of place, phenomenal change by time. It aims to grope for a new approach and possibility to the embodiment and expression of sense space through the expression of sense space approach based on the phenomenological body perception.

• Journal of The Korean Association of Information Education
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• v.23 no.6
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• pp.521-528
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• 2019

The purpose of this study is to design and develop a SW education contents for enhancing computational thinking in elementary information education. First, to develop the SW education program, we divided into three areas: knowledge, skill and attitude. Knowledge is the abstraction in CS, skill is the automation in coding, and attitude as the value of CT. The SW education program was divided into three levels in consideration of difficulty, and each level consisted of 16 subjects. Validation was conducted for 19 SW education experts for the developed program. As a result, the validity of the program was secured beyond the minimum. We hope that this study will be a good resource for SW education that promotes students' computational thinking.

• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.891-900
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• 2000

A Visual development framework for embedded system is presented based on virtual prototyping. Embedded systems often are used in life critical situation, where reliability is very important. Time_to_market, correctness, user_friendly_design are another features required for embedded system design. However, embedded systems are today designed with an ad hoc approach that is heavily based on earlier experience with similar products. We believe that new design paradigm is needed and it should be based on the use of formal model and visual system to describe the behavior of the system at a high level abstraction. Virtual prototyping has all the required features. It has the following advantages; correct design, clear interface definition, idea experimentation, increased communication. In this paper, we describe the design and implementation of VIP/Sim(Virtual Prototyping Simulator), a visionary development framework for embedded system design. New feature such as state polymorphism is augmented to the de_facto standard formal language, statechart, for enhanced dynamic modeling. Actual design experience with VIP/Sim is also discussed.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.340-347
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• 2019

Due to advances in machine intelligence and increased demands for autonomous machines, the complexity of the underlying software platform is increasing at a rapid pace, overwhelming the developers with implementation details. We attempt to ease the burden that falls onto the developers by creating a graphical programming framework we named Splash. Splash is designed to provide an effective programming abstraction for autonomous machines that require stream processing. It also enables programmers to specify genuine, end-to-end timing constraints, which the Splash framework automatically monitors for violation. By utilizing the timing constraints, Splash provides three key language semantics: timing semantics, in-order delivery semantics, and rate-controlled data-driven stream processing semantics. These three semantics together collectively serve as a conceptual tool that can hide low-level details from programmers, allowing developers to focus on the main logic of their applications. In this paper, we introduce the three-language semantics in detail and explain their function in association with Splash's language constructs. Furthermore, we present the internal workings of the Splash programming framework and validate its effectiveness via a lane keeping assist system.

• Journal of Soil and Groundwater Environment
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• v.26 no.6
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• pp.95-105
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• 2021

Extensive groundwater abstraction has been recognized as one of the major challenges in management of coastal groundwater. The purpose of this study was to assess potential changes of groundwater distribution of northeastern Jeju Island over 10-year duration, where brackish water have been actively developed. To quantitatively estimate the coastal groundwater resources, numerical simulations using three-dimensional finite-difference density-dependent flow models were performed to describe spatial distribution of the groundwater in the aquifer under various pumping and recharge scenarios. The simulation results showed different spatial distribution of freshwater, brackish, and saline groundwater at varying seawater concentration from 10 to 90%. Volumetric analysis was also performed using three-dimensional concentration distribution of groundwater to calculate the volume of fresh, brackish, and saline groundwater below sea level. Based on the volumetric analysis, a quantitative analysis of future seawater intrusion vulnerability was performed using the volume-based vulnerability index adopted from the existing analytical approaches. The result showed that decrease in recharge can exacerbate vulnerability of coastal groundwater resources by inducing broader saline area as well as increasing brackish water volume of unconfined aquifers.

• Journal of information and communication convergence engineering
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• v.21 no.4
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• pp.268-280
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• 2023

Several companies have migrated their existing monolithic web applications to microservice architectures. Consequently, research on the identification of microservices from monolithic web applications has been conducted. Meanwhile, the use-case model plays a crucial role in outlining the system's functionalities at a high level of abstraction, and studies have been conducted to identify microservices by utilizing this model. However, previous studies on microservice identification utilizing use-cases did not consider the components executed in the presentation layer. Unlike existing approaches, this paper proposes a technique that considers all three layers of web applications (presentation, business logic, and data access layers). Initially, the components used in the three layers of a web application are extracted by executing all the scenarios that constitute its use-cases. Thereafter, the usage rate of each component is determined for each use-case and the component is allocated to the use-case with the highest rate. Then, each use-case is realized as a microservice. To verify the proposed approach, microservice identification is performed using open-source web applications.