• Journal of IKEEE
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• v.26 no.4
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• pp.722-727
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• 2022

In this paper, we present the design and characterization of a power amplifier (PA) monolithic microwave integrated circuit (MMIC) in the X-band. The device is designed using a 0.25 ㎛ gate length AlGaN/GaN high electron mobility transistor (HEMT) on SiC process. The developed X-band AlGaN/GaN power amplifier MMIC achieves small signal gain of over 21.6 dB and output power more than 46.11 dBm (40.83 W) in the entire band of 9 GHz to 10 GHz. Its power added efficiency (PAE) is 43.09% ~ 44.47% and the chip dimensions are 3.6 mm × 4.3 mm. The generated output power density is 2.69 W/mm². It seems that the developed AlGaN/GaN power amplifier MMIC could be applicable to various X-band radar systems operating X-band.

• Korean Journal of Materials Research
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• v.32 no.12
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• pp.545-552
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• 2022

Tin-antimony sulfide nanocomposites were prepared via hydrothermal synthesis and a N₂ reduction process for use as a negative electrode in a sodium ion battery. The electrochemical energy storage performance of the battery was analyzed according to the tin-antimony composition. The optimized sulfides exhibited superior charge/discharge capacity (770 mAh g^-1 at a current density of 100 mA g^-1) and stable lifespan characteristics (71.2 % after 200 cycles at a current density of 500 mA g^-1). It exhibited a reversible characteristic, continuously participating in the charge-discharge process. The improved electrochemical energy storage performance and cycle stability was attributed to the small particle size, by controlling the composition of the tin-antimony sulfide. By optimizing the tin-antimony ratio during the synthesis process, it did not deviate from the solubility limit. Graphene oxide also acts to suppress volume expansion during reversible electrochemical reaction. Based on these results, tin-antimony sulfide is considered a promising anode material for a sodium ion battery used as a medium-to-large energy storage source.

• Transactions on Semiconductor Engineering
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• v.2 no.1
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• pp.17-20
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• 2024

This paper presents a novel lightweight object detection model tailored for low-powered edge devices, addressing the limitations of traditional resource-intensive computer vision models. Our proposed detector, inspired by the Single Shot Detector (SSD), employs a compact yet robust network design. Crucially, it integrates an 'enhancer block' that significantly boosts its efficiency in detecting smaller objects. The model comprises two primary components: the Light_Block for efficient feature extraction using Depth-wise and Pointwise Convolution layers, and the Enhancer_Block for enhanced detection of tiny objects. Trained from scratch on the Udacity Annotated Dataset with image dimensions of 300x480, our model eschews the need for pre-trained classification weights. Weighing only 5.5MB with approximately 0.43M parameters, our detector achieved a mean average precision (mAP) of 27.7% and processed at 140 FPS, outperforming conventional models in both precision and efficiency. This research underscores the potential of lightweight designs in advancing object detection for edge devices without compromising accuracy.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.11-18
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• 2024

This paper presents a procedure to optimize the design of 70GHz band array antenna for automotive short range radar sensor applications using Chebyshev polynomials. SRR(: Short Range Radar) systems require a wide angle width and low Side lobe level to detect targets within close proximity while ensuring a high Field of View(FoV). The optimized antenna operates in the 76 to 81GHz frequency range, and to reduce the antenna size, we arranged 12 patches in series, achieving an SLL of 10dB, angle with of 112.5o, gain of 15.4dB and an input return loss of less than -10dB at 78GHz. In this paper, we proceed with antenna design for SRR using Chebyshev polynomials, and present an optimal design for antenna structures to be used in MRR(: Medium-Range Radar) and LRR(: Long Range Radar) applications based on this paper

• Journal of the Korea Society of Computer and Information
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• v.29 no.4
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• pp.31-38
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• 2024

This study proposes hyper-parameter settings for developing a generative AI-based learning support tool to facilitate programming education in online distance learning. We implemented an experimental tool that can set research hyper-parameters according to three different learning contexts, and evaluated the quality of responses from the generative AI using the tool. The experiment with the default hyper-parameter settings of the generative AI was used as the control group, and the experiment with the research hyper-parameters was used as the experimental group. The experiment results showed no significant difference between the two groups in the "Learning Support" context. However, in other two contexts ("Code Generation" and "Comment Generation"), it showed the average evaluation scores of the experimental group were found to be 11.6% points and 23% points higher than those of the control group respectively. Lastly, this study also observed that when the expected influence of response on learning motivation was presented in the 'system content', responses containing emotional support considering learning emotions were generated.

• Journal of Korean Philosophical Society
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• v.117
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• pp.35-55
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• 2011

This article purports to clarify the doctrinal characteristics of the $Yog{\bar{a}}c{\bar{a}}ra$ school's hermeneutic interpretations of the "theory of the three turns of the Dharma Cakra" in the Saṃdbinirmocana-sūtra through early Indian $Yog{\bar{a}}c{\bar{a}}ra$ treatises such as the $Yog{\bar{a}}c{\bar{a}}rabb{\bar{u}}mi-vy{\bar{a}}kby{\bar{a}}$ and the. $Vy{\bar{a}}khy{\bar{a}}yukti$. It will probe how these interpretations apply co the theory of two truths or that of three natures($trisvabh{\bar{a}}va$) among the main doctrines of the $Yog{\bar{a}}c{\bar{a}}ra$ school. Especially, the peculiar characteristic of the "theory of the three turns of the Dharma Cakra" is such chat the thought of ${\acute{s}}{\bar{u}}nyat{\bar{a}}$ in the lineage of $Praj{\bar{n}}{\bar{a}}p{\bar{a}}ramita-s{\bar{u}}tras$ is regarded as incomplete, as the early school of Madhyamaka represented by $N{\bar{a}}g{\bar{a}}rjuna$ is conceived of as belonging to the second period of turn. Speaking of the further details of the "theory of the three turns of the Dharma Cakra", the $Yog{\bar{a}}c{\bar{a}}ra$ school subdivides the realm of saṃvṛti satya in $N{\bar{a}}g{\bar{a}}rjuna^{\prime}s$ theory of two truths; that is, it divides the saṃvṛti into merely linguistic existence and actual existence, and the thus-created structure of the theory of three natures on the basis of ocher-dependent nature(paratantra-$svabh{\bar{a}}va$) makes it possible to establish the doctrinal system of the thought of ${\acute{s}}{\bar{u}}nyat{\bar{a}}$ that is not subject to "nihilism or ${\acute{s}}{\bar{u}}nyat{\bar{a}}$ attached to evil." In effect, the above hermeneutic interpretation of the "theory of the three turns of the Dharma Cakra" is inherited into the structure of the $abh{\bar{u}}taparikalpa$ in the $Madhy{\bar{a}}nta-vibh{\bar{a}}ga$ so that, as seen in the commentary of Sthiramati, it is ascertained to apply to later doctrines through its secure establishment. To summarize its characteristics succinctly, firstly the $abh{\bar{u}}taparikalpa$ newly established as a saṃvṛti-satya is set up as the other-dependent nature, which is seen to have been set up particularly in order to sublate both the $Sarv{\bar{a}}stiv{\bar{a}}da^{\prime}s$ realist "view of being" and the Madhyamaka's "view of ${\acute{s}}{\bar{u}}nyat{\bar{a}}$" that impairs the ocher-dependent nature as a samvṛti-satya. In other words, according to the five kinds of views suggested in Sthiramati's commentary, the three natures are seen to be presented as the fundamental truth in order to unify all the doctrinal systems available ever since the beginning of Buddhism. Then, the theory of three natures is established principally on the basis of the $abh{\bar{u}}taparikalpa$, while the two truths of the $Yog{\bar{a}}c{\bar{a}}ra$ school are clearly ascertained to have been embedded in the structure of the $abh{\bar{u}}taparikalpa$. In fact, this might be understood to reflect the unique ontological view of reality or truth in the $Yog{\bar{a}}c{\bar{a}}ra$ School.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.198-215
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• 2012

Green Exhibition and Convention property of the participant satisfaction and impact on the performance of participating companies by looking out for the future development of the national economy on the local economy and help the continued growth of the Green Exhibition and Convention that will help to provide basic data for the purpose of. The results of this study participated in the Green Exhibition and Convention on the expectation of fame exhibit variable, based on the venue, the exhibition publicity, Green Exhibition and Convention Services, Green Exhibition and Convention facilities, information, PC communication or the Internet web site, information, and with the encouragement of those around these parameters and variables of trust as being based on the venue, the exhibition publicity, Green exhibition and Convention Services, Convention and Exhibition as being green in order to increase its influence on expectations and confidence to increase the satisfaction of the variable parameters should be of the utmost importance. Participants to meet the expectations of the variables in the Exhibition, Exhibition of trust, sex, male and recommendation showed by influence. This is an important variable affecting showed. Satisfaction of participants and exhibitors were on.

• KIISE Transactions on Computing Practices
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• v.21 no.2
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• pp.154-159
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• 2015

Over the past few years, user needs in the smartphone application market have been shifted from diversity toward intelligence. Here, we propose a novel cognitive agent that plans the daily routines of users using the lifelog data collected by the smart phones of individuals. The proposed method first employs DPGMM (Dirichlet Process Gaussian Mixture Model) to automatically extract the users' POI (Point of Interest) from the lifelog data. After extraction, the POI and other meaningful features such as GPS, the user's activity label extracted from the log data is then used to learn the patterns of the user's daily routine by POMDP (Partially Observable Markov Decision Process). To determine the significant patterns within the user's time dependent patterns, collaboration was made with the SNS application Foursquare to record the locations visited by the user and the activities that the user had performed. The method was evaluated by predicting the daily routine of seven users with 3300 feedback data. Experimental results showed that daily routine scheduling can be established after seven days of lifelogged data and feedback data have been collected, demonstrating the potential of the new method of place-time-activity coupled daily routine planning systems in the intelligence application market.

• Information Systems Review
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• v.4 no.2
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• pp.323-341
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• 2002

Due to the development of information technology, IT industry has become the core factor of a country competence. So we recognized the importance of information network technology as a basis of IT industry. The infrastructure and service in domestic super-highway information networks show the rapid growth both in quantity and quality because of the government programs. However, foreign information network equipment companies have most of the domestic market-share and have controlled core part of the industry, thus national companies are having a difficulty in penetrating the industry market. In this paper, we will analyze domestic super-highway information network equipment industry and make its activating plan using competitive strategy model.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.171-184
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• 2017

The designers pursue the thoughtful and wide thinking through the accumulation of knowledge and cultivation of insights for making use of high-level design philosophy and language. The purpose of this study is to investigate characteristics of concept figuration types based on designer's 'memory' in landscape design. The results of this study are as follows. First, the design idea starts to be based on the language and image memory of the designer. The figuration types are composed of the verbal and visual view which are representative communication means. Second, the verbal concept figuration of landscape design consists of two types. The symbolic language of the title as a design theme can be a 'phrase', and it should have a hierarchial balance between the master and the sub. 'Descriptive shape of conceptual scenario' is a text that expresses the concept narratively in order that the reader virtually experiences designed landscapes. Third, visual concept figuration of landscape design is divided into three types. 'Simple visualization of a diagram' is easily embodied through a simple graphic using symbols, comments, images and key words. 'Concept sketch and shape of core idea' is useful to grasp the core of the idea such as physical element, form attribute of space and spatial relation at the initial phase of the concept. 'A collage and montage that create a new shape with a combination of images' are a collection of materials and images that provide a new perspective. These are tools to depict them in a compressed way after recording landscapes phenomenon.