• The Journal of the Acoustical Society of Korea
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• v.21 no.3
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• pp.310-314
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• 2002

The exact pitch (fundamental frequency) extraction is important in speech signal processing like speech recognition, speech analysis and synthesis. However the exact pitch extraction from speech signal is very difficult due to the effect of formant and transitional amplitude. So in this paper, the pitch is detected after the elimination of formant ingredients by flattening the spectrum in frequency region. The effect of the transition and change of phoneme is low in frequency region. In this paper we proposed the new flattening method of log spectrum and the performance was compared with LPC method and Cepstrum method. The results show the proposed method is better than conventional method.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.1
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• pp.50-60
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• 2015

A propulsion system of a satellite provides a necessary thrust to reach to the final orbit after a separation from a launch vehicle. Also, it supplies pulse moments to maintain the satellite in a mission orbit and for its attitude controls during a mission life time. The present study investigates the development trend of bipropellant rocket engines for an orbit transfer and an attitude control of a satellite using monomethylhydrazine and hydrazine for fuel and dinitrogen tetroxide for oxidizer to derive fundamental specifications which are necessary for domestic development researches. Also, their major performance characteristics are summarized.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.25-30
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• 2008

This paper presents on research findings of how Visual C++ program can be used to generate codes capable of performing ramjet engine simulation an arbitrary ramjet model will be considered for which generated output values will be compared with those from a commercial program GASTURB 9 Several governing thermodynamic equations will first be discussed in order that we understand the fundamental idea behind values printed out on the GUI. The program is designed that it generates its station input value. Similar results were realized compared to those produced by gasturb 9.

• Structural Engineering and Mechanics
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• v.21 no.5
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• pp.553-570
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• 2005

Dynamic and static analyses of existing structures are very important to obtain reliable information relating to actual structural properties. For this purpose a series of material test, dynamic test and static collapse test of the existing two brick chimneys, in Tokoname, are carried out. From the material tests, Young's modulus and compressive strength of the brick used for these chimneys are estimated to be 3200 MPa and 7.5 MPa, respectively. The results of static collapse test of the existing two brick chimneys are discussed in this paper and composed with the results from FEA (Finite Element analysis). From the results of dynamic tests, the fundamental frequencies of Howa and Iwata brick chimneys are estimated to be about 2.69 Hz and 2.93 Hz, respectively. Their natural modes are identified by ARMAV (Autoregressive Moving Average Vectors) model. On the basis of the static and dynamic experimental tests, a numerical model has been prepared. According to the European code (Eurocode n. 8: "Design of structures for earthquake resistance") non-linear static (Pushover) analysis of the two chimneys is carried out and they seem to be vulnerable to earthquakes with 0.25 to 0.35 g.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1318-1326
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• 2020

Structural modification in the electrical cabinet is investigated by a proposed procedure that comprises of an experimental, analytical and numerical solution. This research emphasizes the linear dynamic analysis of the cabinet that is studied under the seismic excitation to demonstrate the real behavior of the cabinets in NPP. To this end, an actual electric cabinet is experimentally tested using an impact hammer test which reveals the fundamental parameters of the cabinet. The Frequency-domain decomposition (FDD) method is used to extract the dynamic properties of the cabinet from the experiment which is then used for numerical modeling. To validate the dynamic properties of the cabinet an analytical solution is suggested. The calibrated model is analyzed under the floor response obtained from the Connecticut nuclear power plant structure excited by Tabas 1978 (Mw 7.4) earthquake. Eventually, the grouping effect of the cabinets is proposed which represents the influence on the dynamic modification. This grouping of the cabinets is described more sophisticatedly by the theoretical understating, which results in a significant change in the seismic response. Considering the grouping effects will be helpful in the assessment of the real seismic behavior, design, and performance of cabinets.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1557-1569
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• 2017

In recent times, the Internet of Things (IoT) has rapidly emerged as one of the most influential information and communication technologies (ICT). The various constituents of the IoT together offer novel technological opportunities by facilitating the so-called "hyper-connected world." The fundamental tasks that need to be performed to provide such a function involve the transceiving, storing, and analyzing of digital data. However, it is challenging to handle voluminous data with IoT devices because such devices generally lack sufficient computational capability. In this study, we examine the IoT from the perspective of security and digital forensics. SQLite is a light-weight database management system (DBMS) used in many IoT applications that stores private information. This information can be used in digital forensics as evidence. However, it is difficult to obtain critical evidence from IoT devices because the digital data stored in these devices is frequently deleted or updated. To address this issue, we propose Schema Pattern-based Recovery (SPaRe), an SQLite recovery scheme that leverages the pattern of a database schema. In particular, SPaRe exhaustively explores an SQLite database file and identifies all schematic patterns of a database record. We implemented SPaRe on an iPhone 6 running iOS 7 in order to test its performance. The results confirmed that SPaRe recovers an SQLite record at a high recovery rate.

• The Korean Journal of Emergency Medical Services
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• v.15 no.1
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• pp.79-88
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• 2011

Purpose : Prehospital emergency care for shockable rhythm is one of major concerns of emergency medical services. But, in Korea, prehospital medical service systems are not yet well established. We tried to offer one of the fundamental data to develop of these system. Method : After application of exclusion criteria, 200 patients who had shockable rhythm from January to December, 2008 were included in this study. Restrospective review of Prehospital care Reports of these patients was done. Result : Total 200 cases of shockable rhythm and prehospital arrest were analyzed. The rates of assessment of vital signs were 89.0%, the rate of level of consiousness was 99.5%. Just 6.0% were communicated with medical director providing the prehospital care. The frequency of defibrillation was performed 58.5%. Conclusion : Survival rate was higher in defibrillation group than that of nondefibrillation group(20.5% vs 2.4%, p=0.000).

• Journal of the Korea Fashion and Costume Design Association
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• v.22 no.3
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• pp.111-126
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• 2020

The purpose of this study is to understand the gender-neutral phenomenon, to grasp the flow of design, and to seek the future direction of modern fashion design. As for the scope and method of the study, this study was performed based on relevant literature. In terms of visual data, website photos were collected from the collection of S/S in 2016 to F/W in 2020. To assess the properties of the gender-neutral, analysis was implemented on the results after arranging the factors for gender neutrality and the characteristics suggested in the related papers. The fashion-related expert group analyzed the properties of the gender-neutral style from 1,031 pictures, where the gender-neutral style of fashion design collections was applied. As a result of the analysis, the characteristics of the gender-neutral were analyzed and divided into the extended body-positive performance style, the mashup style- respecting the conflicting culture, the street style of coexisting genders, and the fluid style of changing directions. In this study, the attributes were derived as acceptability, playfulness, and sustainability. Accordingly, it is expected that this study will play a fundamental role in the creative fashion design development and unfolding of the fashion industry and fashion designers.

• Child Health Nursing Research
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• v.9 no.3
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• pp.285-293
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• 2003

Purpose: This study was conducted to identify behavioral items for Korean infants under 24months by naturalistic observation. These items will be the basis for developmental scale for Korean infants. Method: Data were collected by observing and interviewing fifty one infants and their mothers during the period from November 15 to December 14, 2003. Raw data in descriptive form were obtained by unstructured naturalistic observation, and were reformed to behavioral items through discussion with professors in pediatric nursing and experienced nurses in child care department. Also, behavioral items were classified into five developmental areas. Result: Total number of behavioral items was two hundreds and thirty eight. 52 items for motor development, 66 items for personal-social, 40 items for hearing and speech, 41 items for eye-hand coordination, and 39 items for performance. Conclusion: This is meaningful that fundamental items for Korean developmental scale for infants were identified by observing behaviors of Korean infants. On the basis of these items, average age will be calculated for passing each item by testing Korean infants. We hope to develop Korean infant developmental scale as a final outcome in the future research.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.191-196
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• 1999

In underground reinforced concrete structures, such as drainage structure, water and chloride ion penetrated into concrete through the cracks of concrete and its permeable property, cause the corrosion of reinforcing steel bar, which accelerates the expansive cracks and deterioration of concrete. It is necessary to control those deterioration of underground structure by improving its permeability and durability through the reasonable solutions in design, construction and materials. In the present study, fly ash concrete, which has good material properties in long-term period, is compared and studied with plain concrete using ordinary portland cement in terms of fundamental mechanical properties, permeability, drying shrinkage and durability. Also, the mix design and its properties of low permeable concrete using fly ash are reviewed. From this study, fly ash concrete can conctrol the penetration of water and chloride ion effectively by forming dense microstructure of concrete. Therefore, fly ash concrete may increase the long-term function, performance and serviceability of underground structures.