• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.66-70
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• 2016

This paper presents an 24 GHz I/Q LO generator for a heartbeat measurement radar system. In order to improve the mismatch performance between I and Q LO signals against process variation, a 24 GHz I/Q LO generator employing a low-pass phase shifter and a high-pass phase shifter composed of inductors and capacitors is proposed. The proposed 24 GHz I/Q LO generator consists of an LO buffer, a low-pass phase shifter and a high-pass phase shifter. It was designed using a 65 nm CMOS technology and draws 8 mA from a 1 V supply voltage. The proposed 24 GHz I/Q LO generator shows a gain of 7.5 dB, a noise figure of 2.3 dB, 0.1 dB gain mismatch and $4.3^{\circ}$ phase mismatch between I and Q-path against process and temperature variations for the operating frequencies from 24.05 GHz to 24.25 GHz.

• Archives of design research
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• no.16
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• pp.125-134
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• 1996

It IS timely and meaningful to research into the procedure of the establishment of the design movement and its role in early twentieth century Britain, which underwent a similar situation to that of current Korea, especially when the development of industrial design is thought to be essential in enhancing nation's competitive power. Besides, the study of the British design movement and design policies resulting from it will set a valuablt, example for us to follow in forming design policies for the betterment of design and in making guidelines for the Korean design movement. Therefore, first. I studil'd circumstances of the period when D.I.:\ was established and the German design movement as well as principles of German I}I.A. as foundation stones for it. Then. I discussed both D.I.A. activities and major figures of the D.I.A. movement in 1~):!O's, l~nO's and l~)~O's. In conclusion, I indicated [xJsitive and negative aspects of the role of D.l.:\.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.201-207
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• 2013

The chirp signaling has been mainly used in radar systems due to its good correlation characteristics, and nowadays it is applied to real time locating system(RTLS). The RTLS with chirp signaling was chosen as a standard such as ISO/IEC 24730-5 and IEEE 802.15.4a. In this paper, the performance of a real time locating system with chirp signaling was evaluated and simulated with relative distance error rates. We considered three cases of S/I = -30[dB], -20[dB], and -10[dB] with Rician factor K=10 and K=20. The performance was enhanced with K factor improvement by 25%, 27% and 50% for respective three cases of S/I. As results, in case of S/I < -20[dB], the minimum signal power is required for performance improvement even though the line of sight component is helpful. And also, in case of S/I ${\geq}$ -20[dB], as the line of sight component is stronger the better performance is obtained.

• The Korean Journal of Pain
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• v.5 no.2
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• pp.199-205
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• 1992

• Journal of the Korea Furniture Society
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• v.23 no.4
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• pp.415-424
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• 2012

Since the Korean War, starvation and severly desperate living conditions hit the whole country. However, Koreans finally overcame such difficulties, achieving the miracle on the Han River. Through rapid industrial developments, Korea would not need any more supports from the outside but rather became a country which would offer a support. Meanwhile, in 1997, the Korean domestic economy underwent IMF which had caused a massive number of unemployeds. Among those people, many began to show interest in D.I.Y woodcraft for a whole new change and eventually, the industry of D.I.Y woodcraft business became expanded. Now, Korea survived I.M.F and was grown as one of the leading countries in the world, having held the G20 summit conference. Such achievements helped national income increased with the domestic GNP of $30,000, having exceeded $20,000. The population also grew to over fifty million and with all these factors, Korea joined the ranks of advanced countries. As a living environment of an individual gets improved and people have had time on their sides due to the five-day workweek, many have been taking this opportunity to engage in self-development and leisure activities. As trends are pursuing eco-friendliness and D.I.Y, D.I.Y woodcraft workshops are opening nationwide. Considering this, as analyzing present conditions of D.I.Y woodcraft workshops, which are being quickly popular at this moment in Korea, this study focuses on presenting a Korean-style D.I.Y woodcraft workshop, suggesting how to promote D.I.Y woodcraft business to be a pivot of the furniture industry in Korea.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.995-997
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• 2005

A plastic substrate for flexible display is developed. The gas barrier and optical properties of the substrate is improved through depositing silicon oxide/nitride layer and coating polymer layer on plastic film by sputtering process and wet coating process. Roll to roll processes will guarantee the productivity in the whole production process of the plastic substrate.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.463-466
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• 2013

We examined relationship between rainfall and triggering of shallow landslides in South Korea, based on hourly rainfall data for 478 shallow landslides during 1963-2012. Rainfall intensity(I) and duration(D) relationship was analyzed to obtain the I-D threshold for the initiation of a shallow landslide using the quantile regression analysis. The I-D threshold equation from in this study is: $I=9.64D^{-0.27}$($4{\leq}D{\leq}76$), where I and D are expressed in millimeters per hour and hours, respectively. In addition, rainfall criteria were proposed to predict the potential to cause landslides, based on values of I-D and cumulative rainfall derived from quantile regression analysis. Our findings may provide essential data and important evidences for the improvement of landslide warning and evacuation system.

• Proceedings of the Korean Vacuum Society Conference
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• 2003.02a
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• pp.68-68
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• 2003

• Journal of applied mathematics & informatics
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• v.30 no.1_2
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• pp.111-125
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• 2012

In this paper, we introduce new classes of generalized convex n-set functions called $d$-weak strictly pseudo-quasi type-I univex, $d$-strong pseudo-quasi type-I univex and $d$-weak strictly pseudo type-I univex functions and focus our study on multiobjective subset programming problem. Sufficient optimality conditions are obtained under the assumptions of aforesaid functions. Duality results are also established for Mond-Weir and general Mond-Weir type dual problems in which the involved functions satisfy appropriate generalized $d$-type-I univexity conditions.

• Journal of applied mathematics & informatics
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• v.38 no.1_2
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• pp.189-200
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• 2020

Let G be a simple connected graph with n vertices and m edges. Denote by d₁ ≥ d₂ ≥ ⋯ ≥ d_n > 0 and d(e₁) ≥ d(e₂) ≥ ⋯ ≥ d(e_m) sequences of vertex and edge degrees, respectively. If vertices v_i and v_j are adjacent, we write i ~ j. The general sum-connectivity index is defined as 𝒳_α(G) = ∑_i~j(d_i + d_j)^α, where α is an arbitrary real number. Firstly, we determine a relation between 𝒳_α(G) and 𝒳_α-1(G). Then we use it to obtain some new bounds for 𝒳_α(G).