• 융합신호처리학회논문지
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• 제7권4호
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• pp.178-183
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• 2006

As a lot of researches on the speech signal processing are performed due to the recent rapid development of the information-communication technology. the pitch period is used as an important element to various speech signal application fields such as the speech recognition. speaker identification. speech analysis. or speech synthesis. A variety of algorithms for the time and the frequency domains related with such pitch period detection have been suggested. One of the pitch detection algorithms for the time domain. AMDF (average magnitude difference function) uses distance between two valley points as the calculated pitch period. However, it has a problem that the algorithm becomes complex in selecting the valley points for the pitch period detection. Therefore, in this paper we proposed the modified AMDF(M-AMDF) algorithm which recognizes the entire minimum valley points as the pitch period of the speech signal by using the rotation transform of AMDF. In addition, a threshold is set to the beginning portion of speech so that it can be used as the selection criteria for the pitch period. Moreover the proposed algorithm is compared with the conventional ones by means of the simulation, and presents better properties than others.

• 한국군사과학기술학회지
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• 제20권1호
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• pp.98-107
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• 2017

Electric components equipped with naval shipboards must endure mechanical shock caused by various mechanical impulsive sources. Thus the components must be designed carefully and reliability test is an essential procedure before use. In this study, a new design technology applicable to a large and heavy shock generation system which can generate various specific real mechanical shocks in specified time domain was introduced. Commonly, the shock transmitted through the wall of naval shipboard consists of dual shocks. The primary shock is of a very high amplitude and very short period half-sine form. The following shock is of an exponentially decaying harmonic form of relatively longer period. Based on the different dynamic characteristics of two shocks, we proposed a sequential design procedure to determine spring and damping coefficients of the generation system. Some numerical simulation results showed the feasibility of the proposed method.

• Design & Manufacturing
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• 제14권2호
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• pp.49-55
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• 2020

Recently, when a new component of construction equipment is designed, a stamping process capable of producing parts having high appearance quality and precision has been gaining attention. However, in general, as it is developed based on existing parts made by welding metal sheets and tubes, frequent to die modification occurs, which increases the time and cost of developing new parts. Thus, it is necessary to reduce the cost by shortening the die development period. In this study, a stamping process was designed for the urea tank cover, which is a part for excavators, to reduce the die development period through sheet metal forming analysis. The stamping process was designed by determining the blank holding force after selecting the initial blank shape and size. The round value at the corner was modified such that formability is ensured. After selecting process parameters, the thickness reduction rate and spring-back effect were reviewed.

• Journal of Animal Science and Technology
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• 제62권6호
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• pp.875-883
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• 2020

This study was conducted to investigate the effects of group-housing facility (GHF), compared to an individual confinement stall (CON), on the reproductive performance, behavior, and stress hormones of gestating sows. A total of 50 primiparous sows (Landrace × Yorkshire) were randomly allocated into either CON (n = 25) or GHF (n = 25) during the gestation period. One week before parturition, the sows were transferred into conventional farrowing crates, and cross-fostering was conducted within 1 d of delivery. Blood was collected for analyses of stress indices at 75 d of gestation and postpartum. Reproductive performance was estimated during the period of birth to weaning. Behavior patterns were identified at 90 d of gestation. Litter size was not different between the CON and GHF treatments. Weaning to estrus interval, however, tended to be lower in the GHF than in the CON (p < 0.1). Activity, treating, belly nosing, and exploring behaviors were observed only in the GHF group, whereas rubbing was shown only with the CON. Serum cortisol concentration was lower in the GHF than in the CON at 75 d of gestation (p < 0.05). Sows housed in the GHF showed lower epinephrine and norepinephrine concentrations than those housed in the CON at postpartum (p < 0.05). The GHF sows demonstrated more natural behavior characteristics associated with stress relief than the CON sows with no adverse effects on reproductive performance. Therefore, these results suggest that GHF could be applied as an alternative housing facility to improve animal welfare on swine farms.

• 교육시설
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• 제5권2호
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• pp.16-29
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• 1998

Bell Laboratory introduced the sound and visual system for the first time in 1927. Since then, the development of telecommunication technology made it possible for people located far away to communicate each other watching through the TV screen. Over the period different types of telelecturing systems have prospered in line with the development of telecommunication technology. Therefore, it is quite natural that telelecturing/conferending system attracts the attention of many people as a new way of educating people located in a long distance. In the industrial sector, telelecturing systems already come into wide use to save time and training and travelling expense. In this study, I examine the concept and characteristics of telelecturing/conferencing system and introduce different types telelecturing system developed in parallel with the development of communication technology. Then, I analyze how those merits of the telelecturing system can be applied to educational purpose. Finally, I propose and design ideal telelectuirng/conference facilities consisting of telelecturing rooms, bilateral movie system, seats, ceilings, color, TV screen, lighting, acoustics, humidities and temperature control, security system, projection system to maximize the educational purpose and effectiveness.

• KSBB Journal
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• 제30권1호
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• pp.27-32
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• 2015

The current investigation was carried out to explore the possibility of submerged fermentation of Saccharina japonica as sole substrate using Aspergillus oryzae. In this study we used 2% S. japonica powder as fermentation media for A. oryzae. Fermentation period was optimized by monitoring the fermented sample at regular intervals for a period of 7 days. Results found that a fermentation period of 5 days was effective with maximum desirable characteristics such as total sugar, total phenolic and flavonoid contents. Under optimum fermentation period, fermented extracts showed enhanced antioxidant activity as determined by different assays such DPPH radical scavenging, ABTS scavenging and phosphomolydenum assay. This study provides the information for the enhancement of bioactive molecules in an eco-friendly manner and also paves way towards the development of wide range of seaweed-based functional foods.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.29-35
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• 2021

This study discusses the effect of human capital and technology on economic growth in Indonesia using annual time series data over the 35-year research period (1984-2019). This study uses an autoregressive distribution gap to the cointegration approach to understanding the relationship between human capital, technology, and economic growth. Human capital is inherent in humans and becomes capital in providing the best performance that has an impact on their own income. We use the human capital framework in this study where education is one mechanism to increase human capital. Based on the results of our estimation, we find that the increase in human capital using the education mechanism affects economic growth. This shows the role of human capital investment is very important in economic growth. Technology shows a significant positive effect on economic growth. Increasing human resources and technology are important factors in efforts to increase economic growth in Indonesia. Educational development is the key to the success of increasing human capital and technological development because education plays a role in improving the quality of human resources. Increasing human resources here is in the form of increased knowledge, mastery of technology, innovation, and the ability to develop technology to encourage technology development.

• 한국멀티미디어학회논문지
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• 제23권2호
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• pp.227-240
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• 2020

This paper proposes a novel CTC technology, CB-sense. The CB-sense guarantees a dedicated period for the CTC that results in low duty cycle of the receiver device. In addition, it send a lot of information explosively during the dedicated CTC period. Thus, it can achieve high throughput. The CB-sense uses Clear to Send (CTS) packets to transmit information bits to the heterogeneous wireless technologies. The CTS packets block the neighboring node transmissions, so it reduces co-channel interference. In experiment results, CB-sense represents 20 times more throughput than FreeBee and below 5% symbol error rate in the interference environment.

• Nuclear Engineering and Technology
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• 제43권1호
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• pp.89-98
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• 2011

The construction technology for reactor vessel internals (RVI) modularization is one of the most important factors to be considered in reducing the construction period of nuclear power plants. For RVI modularization, gaps between the reactor vessel (RV) core-stabilizing lug and the core support barrel (CSB) snubber lug must be measured using a remote method from outside the RV. In order to measure RVI gaps remotely at nuclear power plant construction sites, certain core technologies must be developed and verified. These include a remote measurement system to measure the gaps between the RV core-stabilizing lug and the CSB snubber lug, an RVI mockup to perform the gap measurement tests, and a new procedure and schedule for RVI installation. A remote measurement system was developed previously, and a gap measurement test was completed successfully using the RVI mockup. We also developed a new procedure and schedule for RVI installation. This paper presents the new and improved installation procedure and schedule for RVI modularization. These are expected to become core technologies that will allow us to shorten the construction period by a minimum of two months compared to the existing installation procedure and schedule.

• 반도체디스플레이기술학회지
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• 제18권3호
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• pp.127-132
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• 2019

This paper presents an overview of automotive communication technologies, including related technology developments. We describe the latency of Audio Video Bridge (AVB) network as well as purpose the optimized design of the Ethernet network system for automotive. Our design plays a significant role in reducing the delay between components. The proposed approach on realistic test cases showed that there was a delay reduction, approximately 49.4%. It is expected that the optimization method for the actual automotive environment can greatly shorten the time period in the design and development process. The results obtained from the experiments on the delay time present in each function are reliable because average values are obtained through repeated actual tests for several months. It will greatly benefit the industry since analyzing the latency between each function in a short period of time is very important.