• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.3
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• pp.114-123
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• 2016

The effective feature extraction method for unmanned aerial vehicle (UAV) detection is proposed and verified in this paper. The UAV engine sound is harmonic complex tone whose frequency ratio is integer and its variation is continuous in time. Using these characteristic, we propose the feature vector composed of a mean and standard deviation of difference value between fundamental frequency with 1st overtone as well as mean variation of their frequency. It was revealed by simulation that the suggested feature vector has excellent discrimination in target signal identification from various interfering signals including frequency variation with time. By comparing Fisher scores, three features based on frequency show outstanding discrimination of measured UAV signals with low signal to noise ratio (SNR). Detection performance with simulated interference signal is compared by MFCC by using ELM classifier and the suggested feature vector shows 37.6% of performance improvement As the SNR increases with time, the proposed feature can detect the target signal ahead of MFCC that needs 4.5 dB higher signal power to detect the target.

• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.81-90
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• 2013

During adolescence the mutational period is characterized by the changes in the laryngeal structure, the length of the vocal cords, and a tone of voice. Usually, adolescents at 15 or 16 reach the voice of adults but the mutational period is sometimes delayed. Therefore, studies on the voice of adolescents between 16 ~ 18 right after the mutational period are required. Accordingly, this paper attempted to provide basic data about the normal standard for patients with voice disorders during this period by evaluating the vocal characteristics of males and females between 16 ~ 18 with an objective device bycomparing and analyzing them by sex and age. The study was conducted on a total of 60 subjects composed of each 10 subjects of each age. The vocal analysis was conducted by MPT (Maximum Phonation Time) measurement, sustained vowels and sentence reading. As for /a/ sustained vowels, fundamental frequency, hereinafter referred to as $F_0$, jitter, shimmer, noise-to-harmonic ratio, hereinafter referred to as NHR were measured by using the Multi-dimensional voice program (MDVP) among the Multi-Speech program of Computerized Speech Lab (Kay Elemetrics). The sentence reading, mean $F_0$, maximum $F_0$ and minimum $F_0$ were measured using the Real-Time Pitch (RTP) Model 5121 among the Multi-Speech program of Computerized Speech Lab (Kay Elemetrics). As a result, according to sex, there were statistically significant differences in $F_0$, jitter, shimmer, mean $F_0$, maximum $F_0$, and minimum $F_0$; and according to age, there were statistically significant differences in MPT. In conclusion, the voice of the adolescents between 16 ~ 18 reached the maturity levels of adults but the voice quality which can be considered on the scale of voice disorders showed transition to the voice of an adult during the mutational period.

• Speech Sciences
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• v.14 no.4
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• pp.25-39
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• 2007

The present study investigated some perceptual phonetic attributes of two Korean stop types, aspirated and lax, in medial position of an accentual phrase. The intonational pattern across syllables (Jun, 1993) is argued to depend on the type of stop (aspirated vs. lax) only in the initial position of an accentual phrase. In Kang & Dilley (2007), we showed that significant differences between aspirated and lax stops in medial position of an accentual phrase exist in closure duration, voice-onset time, and fundamental frequency (F0) values for post-stop vowels. In the present perception experiment, we investigated whether these phonetic attributes contribute to the perception of these two types of stops: The closure durations and/or F0's of post-stop vowels on accentual-phrase medial words were altered and twenty native Korean speakers then judged these words as beginning with an aspirated or lax stop. Both closure duration and F0 significantly affected judgments of stop identity. These results indicate that a wider range of acoustic cues that distinguish aspirated and lax Korean stops in production also plays a role in perception. To account for these results we suggest some phonetic and phonological models of consonant-tone interactions for Korean.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.3-23
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• 2007

King Sejong the Great, his students in Jip-hyeun-jeon school and Choe Sejin, their successor of the sixteenth century, indicated Middle Korean had three distinctive pitches, low, high, and rising (phyeong-, geo-, sang-sheong). Thanks to $Hun-min-jeng-{\emptyset}eum$ as well as its Annotation and side-dots literatures in fifteenth and sixteenth centuries, we can compare Middle Korean with Hamgyeong dialect, Gyeongsang dialect, and extant tone dialects with joint preservers of what was probably the tonal system of unitary mother Korean language. What is most remarkable about middle Korean phonetic work is its manifest superiority in conception and execution as anything produced in the present day linguistic scholarship. But at this stage in linguistics, prior to the technology and equipment needed for the scientific analysis of sound waves, auditory description was the only possible frame for an accurate and systematic classification. And auditory phonetics still remains fundamental in pitch description, even though modern acoustic categories may supplement and supersede auditory ones in tonological analysis. Auditory phonetics, however, has serious shortcoming that its theory and practice are too subject to be developed into the present century science. With joint researchers, I am developping a new pitch scale. It is a semiautomatic auditory grade pitch analysis program. The result of our labor will give a significant breakthrough to upgrade our component in linguistics.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.17 no.4
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• pp.539-547
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• 2010

Purpose: This study was done to determine the effects of aromatherapy on anxiety and discomfort for patients who were having colonoscopy. Methods: The study used a nonequivalent control group non-synchronized design. The participants were 48 people who were undergoing colonoscopy in a university hospital. The experimental group inhaled a blend of essential oil with neroli, camomile, lavender and lemon through an aroma stone for 5minutes before the examination. Then the aroma stone was put on the side of the pillow to spread the aroma scent in the room. The experimental group could inhale the aroma scent as soon as they came into the room and during the examination process. The control group received only fundamental nursing care. Results: Aromatherapy significantly decreased VAS anxiety. There were also significant differences in facial change and, tone change for objective discomfort. But there were no significant differences in subjective discomfort between the groups nor were there any significant differences in vital signs. Conclusion: Aromatherapy was perceived as an useful intervention to reduce anxiety and objective discomfort of patients receiving colonoscopy. The results of this study could be utilized as a clinical nursing intervention.

• Journal of electromagnetic engineering and science
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• v.7 no.4
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• pp.147-153
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• 2007

This paper represents an analog predistortion linearizer for the high power amplifier with low memory effect. The high power amplifier is implemented using a 90-W peak envelope power(PEP) LDMOSFET at 2.14-GHz and an envelope short matching topology is applied at the active ports to minimize the memory effect. The analog predistortion circuit comprises the fundamental path and the cuber and quintic generating circuits, whose amplitudes and phases can be controlled independently. The predistortion circuit is tested for two-tone and wide-band code division multiple access(WCDMA) 4FA signals. For the WCDMA signal, the adjacent channel leakage ratios(ACLRs) at 5 MHz offset are improved by 12.4 dB at average output powers of 36 dBm and 42 dBm.

• Korean Institute of Interior Design Journal
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• v.22 no.1
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• pp.183-193
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• 2013

The study aimed to find the fundamental differences of aesthetics in Korea, China, and Japan by analyzing expressive features and structural meanings of the storage furniture from $17^{th}$ to $19^{th}$ century. The study was performed in four steps; analysis of expressive features, isotopic analysis, semantic structure analysis, and comprehensive interpretation. The results showed that three countries had linear shapes with curvilinear elements, closed forms with open spaces, natural material hues with change of tone or color, and symmetrical forms with asymmetrical patterns and structures in common. Korea comparatively accented on the natural material colors and wood grains. China stressed on the big and wide faces using three-dimensional carving. Japan accented on the linear elements with strong color contrast and decorative metal fixtures. These features were caused by the traditional thoughts and according aesthetic principles. Korea and China were affected by the Confucianism focused on establishing the order of rank. Meanwhile, Japan was more influenced by the Buddhism emphasized on the individuality and communication. Therefore, the differences of the expressive features in furniture among the three countries were inevitable consequences of the different ideologies.

• The Journal of the Acoustical Society of Korea
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• v.6 no.1
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• pp.39-47
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• 1987

It is well-known that analogizing a dynamic system to an equivalent circuit is a powerful tool on the analysis of the system. In this paper, an equivalent circuit of the piano has been constructed by the structural and acoustical analysis to visualize the sounding mechanism. Utilizing the mechanical reactance curve of the soundboard, a new method of reducing che inharmonicity in low frequency range has been built. With this method, by only choosing the proper excitation point on the soundboard, it will be possible to minimize the inharmonicity and thus to obtain mellow bass tone. It is shown that the missing fundamental in the lowest scale range results predominatly from the fact that the radiation impedance in such low frequencies is nearly pure reactive.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.873-876
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• 2008

Although Permeable concrete is resently used as a pavement at a parking lot, a public squre and a bicycle road, we use without enough examining. most the maintenance of quality for Permeable concrete is only dealt with strength and color tone. also, there is not yet enough fundamental data about dynamical properties for strength, rate of void and water permeability. even when it is applied to at the scene, it is been a matter.

• Korean Institute of Interior Design Journal
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• v.18 no.6
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• pp.69-76
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• 2009

As sensibility ergonomics are broadly spread, recently in interior design area, interests on roles of sensibility, sensibility effects for users, and etc has been increased. As a study on sensibility design for interior design area, the study applied sensibility ergonomics technique to bathroom interior design. Sensibility ergonomics technique is integrated into each phase of bathroom design process in order to produce 4 design alternatives. Sensibility evaluation on design alternatives was performed for subject of designers, and analyzed the results to show the relationship between sensibility of designers and design factors and to identify characteristics of designer's sensibility structure. The results of the study are as follows. First, it's found that in the bathroom interior design of sustainable concept, uses of bright colors with white tone and floor tile creates positive sensibility responses such as delight, healthiness, spaciousness, and cheerfulness. Second, designers' sensibility structure about sustainable bathroom is composed of three axles, healthiness, eco-friendliness, and refinement. Third, designers think colors of interior and finished materials is most important, and window, artificial lighting, layout, and space size related to those is important too. The process and approach in the study might contribute to building a fundamental of sensibility design research in interior design area.