• The Journal of the Acoustical Society of Korea
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• v.32 no.5
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• pp.385-392
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• 2013

The sound generated from the formula 1 (F1) machine is characteristic in that the frequency felt by the listener changes drastically by the Doppler effect as the machine bypasses him. In textbooks, longitudinal Doppler effect is usually described. In this paper, we consider a more general case where the listener is away from the rectilinear path of the machine's motion. As the machine bypasses the listener, in this case, the frequency drops not abruptly but gradually, the temporal width for the frequency drop depending on the machine's speed. The frequency shift felt by the listener is analyzed as functions of time and/or machine location in our study. The machine's speed is estimated from the frequency analysis of an actual F1 sound.

• The Journal of the Acoustical Society of Korea
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• v.39 no.1
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• pp.32-37
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• 2020

This paper proposes a new l₁-norm-Recursive Least Squares (RLS) algorithm which is numerically more robust than the conventional l₁-norm-RLS. The l₁-norm-RLS was proposed by Eksioglu and Tanc in order to estimate the sparse acoustic channel. However the algorithm has numerical instability in the inverse matrix calculation. In this paper, we propose a new algorithm which is robust against the numerical instability. We show that the proposed method improves stability under several numerically erroneous situations.

• The Journal of the Acoustical Society of Korea
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• v.34 no.5
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• pp.371-376
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• 2015

In this study, we use 1:1, 1:2, and 1:4 scale zig-zag shape acoustic metamaterial structure to achieve broad and effective sound blocking at the subwavelength scale. The SPL(Sound Pressure Level) results show that the SPL loss of the scaled metamaterial slab in series is a superposition of individual SPL losses. Also, we show that the metamaterial tailors the material properties to achieve high impedance and high refractive index using effective medium theory. Our results show that broad and effective sound blocking is possible at the subwavelength scale just by scaling acoustic metamaterial.

• The Korean Journal of Emergency Medical Services
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• v.4 no.1
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• pp.35-46
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• 2000

The results of analyzing the cognition of CPR by college students who major in public health or not order to enhance the educational efficiency of first aid ability and its expansion are as follows. 1. In case of students majoring in public health, the students who have the knowledge of term 'CPR' are 95.3% of total 300 students and 62.6% of the students who don't major in public health know it. In the item test of examining the degree of theoretical knowledge of CPR, the cases who know all 12 items are 5.2% and 1.6% respectively in cases who major in public health and don't major in it and it is judged that the extension of educational opportunity for them should be urgent. 2. The students who have experienced the practice of CPR are 20.6% in case who major in public health and 7.4% in other case. Therefore it seems to desirable that indirect field experience should be obtained by strengthening practice centered education. 3. The order of practice to examine the CPR ability is asked and the students who show very good remark are just 21~22% in both cases and they conducted very ineffective CPR and it is examined that they did first aid which may a serious damage to patients. Then the cases who recovered pulse and respiration after CPR were very low as 28.8% in the students who major in public health and 35.7% in others. It is therefore considered that the exact education of conducting the maintenance of respiratory trace, artificial respiration and CPR is necessary. 4. The cases who had the education of CPR were 51% in the students who major in public health and 39.4% in others, who had little opportunities to have CPR and 92.5~93.2% in both groups fee the necessity of continuous education and it is very encouraging to extend the education of CPR. 5. The education of CPR is mainly done at school (70.3~79.4%) and from teachers (52.7~55.4%) and 71.2% of the students majoring in public health responded that it is good for them to have education of CPR at school and lecture by first-aider and 58.9% of others did it. The cases who ask for lecture by the Professors of Dept. of First-Aid are 11.8 in students majoring in public health and 13.1% in others and it is judged that lecture by them having the theoretical foundation and first-aider with practical ability will be desirable. 6. On teaching methods, 57.5% of the cases majoring in public health and 63.3% of others ask for practice and 20% of both groups need theory centered teaching. 7. On lecture fee, 83% of the cases majoring in public health and 83.3% of others consider it should be free and 8~11.8% who are to pay for 10,000 won and it is judged that it should be opened and operated as liberal arts by college in the dimension of lifelong education. 8. On the objects of education, 83% of cases majoring in public health and 66.6% of others consider it should be conducted in people of all ages and both sexes and it is known that everyone recognizes the necessity of popularizing the education of first-aid.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.10
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• pp.45-52
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• 2008

We investigated the design of an RF-powered, wireless temperature sensor tag chip using $0.18-{\mu}m$ CMOS technology. The transponder generates its own power supply from small incident RF signal using Schottky diodes in voltage multiplier. Ambient temperature is measured using a new low-power temperature-to-voltage converter, and an 8-bit single-slope ADC converts the measured voltage to digital data. ASK demodulator and digital control are combined to identify unique transponder (ID) sent by base station for multi-transponder applications. The measurement of the temperature sensor tag chip showed a resolution of $0.64^{\circ}C/LSB$ in the range from $20^{\circ}C$ to $100^{\circ}C$, which is suitable for environmental temperature monitoring. The chip size is $1.1{\times}0.34mm^2$, and operates at clock frequency of 100 kHz while consuming $64{\mu}W$ power. The temperature sensor required a -11 dBm RF input power, supported a conversion rate of 12.5 k-samples/sec, and a maximum error of $0.5^{\circ}C$.

• Journal of Popular Narrative
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• v.26 no.1
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• pp.41-76
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• 2020

Recently, the cinema industry faced a crisis on the rise of various media platforms such as Netflix, Amazon Prime, IPTV, and Kakao Page. The rate of film release in the theater has become ever shorter, and the secondary consumption of film through IPTV, tablet, PC, or mobile has seen a drastic increase. In the midst of this new media-geography, the most significant change in recent years would be the rise of the 'fantasy film' genre. This paper explores the conditions and characteristics of fantasy films in the way in which the genre has been constituted, and delves into particular aspects that its contents contain. This is an attempt to understand the sociology of the birth of a new genre. In this process, this paper will ask two frequently raised questions in regard to this genre. The first is to ask whether we can discern fantasy from reality, and the second is to examine whether the fantasy genre implicates certain social subversion. These two questions aim to discover how fantasy forms a relationship with reality and what this means. To do so, this paper will trace the genealogy of the fantasy film genre in Korea and analyze recent big hits such as the series as the model case of digital fantasy film. Through this exploration, this paper will be able to provide a new sociology of the fantasy film production and consumption in the 21^st century Korea.

• The Journal of the Acoustical Society of Korea
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• v.32 no.6
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• pp.502-508
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• 2013

In this paper, 2D array transducers using a conductive backer similar to 1-3 composites have been designed, fabricated, and evaluated. The conductive backer was based on well known manufacturing process of 1-3 composites with affordable ingredients. The 2D array transducer had 4,096 elements designed to have 3.5 MHz center frequency and a fractional bandwidth over 60 %. Fabricated prototype of the transducer satisfied the specifications in the center frequency and bandwidth. Performance over the entire elements was so uniform that the standard deviation was less than 0.81 dB. Thus applicability of the conductive backer proposed in this work to 2D array transducers was verified.

• Clinical and Experimental Reproductive Medicine
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• v.42 no.1
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• pp.1-7
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• 2015

Stress coping mechanisms are critical to minimize or overcome damage caused by ever changing environmental conditions. They are designed to promote cell survival. The unfolded protein response (UPR) pathway is mobilized in response to the accumulation of unfolded proteins, ultimately in order to regain endoplasmic reticulum (ER) homeostasis. Various elements of coping responses to ER stress including Perk, Ask1, Bip, Chop, Gadd34, Ire1, Atf4, Atf6, and Xbp1 have been identified and were found to be inducible in oocytes and preimplantation embryos, suggesting that, as a normal part of the cellular adaptive mechanism, these coping responses, including the UPR, play a pivotal role in the development of preimplantation embryos. As such, the UPR-associated molecules and pathways may become useful markers for the potential diagnosis of stress conditions for preimplantation embryos. After implantation, ER stress-induced coping responses become physiologically important for a normal decidual response, placentation, and early organogenesis. Attenuation of ER stress coping responses by tauroursodeoxycholate and salubrinal was effective for prevention of cell death of cultured embryos. Further elucidation of new and relevant ER stress coping responses in periimplantation embryos might contribute to a comprehensive understanding of the regulation of normal development of embryonic development and potentiation of embryonic development in vitro.

• The Journal of the Acoustical Society of Korea
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• v.27 no.1
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• pp.26-32
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• 2008

UBSS (unde-determined blind source separation) is composed of the stages of BMMR (blind mixing matrix recovery) and BSR (blind source recovery). Generally, these two stages are executed using the sparseness of the observed data, and their performance is influenced by the accuracy of the measure of the sparseness. In this paper, as introducing the measure of the sparseness using the Gini coefficient to BSR stage, we obtained more accurate measure of the sparseness and better performance of BSR than methods using the $l_1$-norm, $l_q$-norm, and hyperbolic tangent, which was confirmed via computer simulations.

• The Pure and Applied Mathematics
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• v.10 no.4
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• pp.265-271
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• 2003

Let $CS_\alpha(\beta)$ denote the class of normalized strongly $\alpha$-close-to-convex functions of order $\beta$, defined in the open unit disk $\cal{U}$ of $\mathbb{C}$${\mid}arg{(1-{\alpha})\frac{f(z)}{g(z)}+{\alpha}\frac{zf'(z)}{g(z)}}{\mid}\;\leq\frac{\pi}{2}{\beta}(\alpha,\beta\geq0)$ such that $g\; \in\;S^{\ask}$, the class of normalized starlike unctions. In this paper, we obtain the sharp Fekete-Szego inequalities for functions belonging to $CS_\alpha(\beta)$.