• ETRI Journal
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• 제32권2호
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• pp.281-291
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• 2010

Scalable video coding (SVC) has been standardized as an extension of the H.264/AVC standard. This paper proposes a practical real-time transport protocol (RTP) packetization scheme to transport SVC video over IP networks. In combined scalability of SVC, a coded picture of a base or scalable enhancement layer is produced as one or more video layers consisting of network abstraction layer (NAL) units. The SVC NAL unit header contains a (DID, TID, QID) field to identify the association of each SVC NAL unit with its scalable enhancement layer without parsing the payload part of the SVC NAL unit. In this paper, we utilize the (DID, TID, QID) information to derive hierarchical spatio-temporal relationship of the SVC NAL units. Based on the derivation using the (DID, TID, QID) field, we propose a practical RTP packetization scheme for generating single RTP sessions in unicast and multicast transport of SVC video. The experimental results indicate that the proposed packetization scheme can be efficiently applied to transport SVC video over IP networks with little induced delay, jitter, and computational load.

• 한국산업정보학회논문지
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• 제7권3호
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• pp.74-80
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• 2002

한국어 연속 음성 인식결과의 성능향상을 위해서 자연어 처리 기술을 이용한 후처리 기법이 사용된다. 그러나 자연어 처리 기법이 대부분 띄어쓰기가 있는 정형화된 입력 문장에 대한 분석을 수행하여 왔기 때문에 형태소 분석기를 직접 음성인식 결과의 향상에 사용하는 데에는 어려운 점이 많다. 본 논문에서는 띄어쓰기를 고려하지 않는 기능어 기반의 최장일치 형태소 해석 방법인 구문 형태소 단위의 분석을 이용한 음정인식 결과의 향상 모델을 제안한다. 제안된 모델을 통해 연속음성 인식 결과에서 자주 발생하는 용언과 보조 용언 및 의존 명사 사이의 음운들 사이의 구조적 정보를 활용함으로써 음성 인식 결과의 성능을 향상시키는 방법에 대해 기술한다.

• 대한기계학회논문집B
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• 제24권3호
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• pp.363-372
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• 2000

An experiment was carried out to evaluate the heat transfer enhancement and the pressure drop characteristics for liquid nitrogen using wire-coil-insert technique under horizontal two-phase conditions. The tube inner diameters were 8 mm and 15 mm, respectively and the tube length was 4.7 m. The helix angle of the wire coil insert was $50^{\circ}$ and its length was 4.7 m. Heat transfer coefficients for both the plain and the enhanced test tubes were calculated from the measurements of temperatures, flow rates and pressure drops. A correlation in a power-law relationship of the Nusselt number, Reynolds number and Prandtl number for the heat transfer was proposed which can be available for design of cryogenic heat exchangers. The correlation showed that heat transfer coefficients for the wire-coil inserts were much higher than those for plain tubes, increased by more than $1.8{\sim}2.0$ times depending upon the range of the equivalent Reynolds number. The correlation was compared with other various correlations in the turbulent flow conditions.

• Coupled systems mechanics
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• 제6권3호
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• pp.335-349
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• 2017

To cope with the demand on giant and durable buildings, reinforcement of concrete is a practical problem being extensively investigated in the civil engineering field. Among various reinforcing techniques, fiber-reinforced concrete (FRC) has been proven to be an effective approach. In practice, such fibers include steel fibers, polyvinyl alcohol (PVA) fibers, polyacrylonitrile (PAN) carbon fibers and asbestos fibers, with the length scale ranging from centimeters to micrometers. When advancing such technique down to the nanoscale, it is noticed that carbon nanotubes (CNTs) are stronger than other fibers and can provide a better reinforcement to concrete. In the last decade, CNT-reinforced concrete attracts a lot of attentions in research. Despite high cost of CNTs at present, the growing availability of carbon materials might push the usage of CNTs into practice in the near future, making the reinforcement technique of great potential. A review of existing research works may constitute a conclusive reference and facilitate further developments. In reference to the recent experimental works, this paper reports some key evaluations on CNT-reinforced cementitious materials, covering FRC mechanism, CNT dispersion, CNT-cement structures, mechanical properties and fire safety. Emphasis is placed on the interplay between CNTs and calcium silicate hydrate (C-S-H) at the nanoscale. The relationship between the CNTs-cement structures and the mechanical enhancement, especially at a high-temperature condition, is discussed based on molecular dynamics simulations. After concluding remarks, challenges to improve the CNTs reinforcement technique are proposed.

• Journal of Korean Neurosurgical Society
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• 제48권6호
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• pp.524-527
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• 2010

Temporary disruption of the blood-brain barrier (BBB) after cerebral angiography is presumably caused by nonionic radiographic contrast medium (CM). We hereby report a case of 58-year-old woman who developed decreased mentality, global aphasia and aggravated right hemiparesis after cerebral angiography. Brain CT examination demonstrated gyriform enhancement throughout the left cerebral cortex and thalamus. MR diffusion did not reveal acute infarction. MR angiography did not show any stenosis, spasm or occlusion at the major cerebral vessels. Follow-up CT scan after 1 day did not show any gyriform enhancement. Worsened neurologic signs and symptoms were improved completely after 7 days. In the present study, disruption of the BBB with contrast medium after angiography seems to be the causative factor of transient neurologic deterioration.

• 센서학회지
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• 제30권6호
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• pp.408-414
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• 2021

This study analyzes the phase transition behavior and electrical properties of lead-free (1-x)K_0.5Na_0.5NbO₃-xBaZrO₃ (KNN-100xBZ) piezoelectric ceramics. The stabilized crystal structures in BaZrO₃-modified KNN ceramics is clarified to be pseudocubic. The polymorphic phase transition from the orthorhombic to pseudocubic phases can be observed with KNN-6BZ ceramics considering the optimized piezoelectric constant (d₃₃). Electromechanical strain behaviors are discussed. Accordingly, the enhancement of strain value at x = 0.08 (composition) may originate from the coexistence of ferroelectric domains and polar nanoregions. A schematic of domains for KNN, KNN-8BZ, and KNN-15BZ ceramics has been proposed to describe the relationship between the stabilized relaxor and changes in electrical properties.

• 국제강구조저널
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• 제18권5호
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• pp.1577-1588
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• 2018

As the excellent mechanical performance and easy construction of concrete filled steel tubes (CFST) composite structure, it has the potential to be used to strengthen RC pier columns. Therefore, tests were conducted on 2 reinforcement concrete (RC) stub columns and 9 RC columns strengthened with circular CFST under axial loading. The test results show that the circular CFST strengthening method is effective since the mean bearing capacity of the RC columns is increased at least 3.69 times and the ductility index is significantly improved more than 30%. One of the reasons for enhancement is obvious confinement provided by steel tube besides the additional bearing capacity supplied by the strengthening materials. From the analysis of the enhancement ratio, the strengthening structure has at least an extra 20% amplification except for taking full advantage of the strength of the strengthening material. Through the analysis of confining stress provided by steel tube and the stress-strain relationship of confined concrete, it is found that the strength of the core concrete can be increased by 21-33% and the ultimate strain can be enhanced to beyond $15,000{\mu}{\varepsilon}$.

• 유통과학연구
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• 제20권7호
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• pp.1-9
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• 2022

Purpose: This study aims to examine the effect of intellectual capital on both internal and external collaboration and its impact on distribution performance enhancement in public sector. Research design, data, and methodology: The study applied quantitative approach with the help of AMOS Structural Equation Modelling. The unit of analysis is the Indonesian local government. The research involved 430 leaders from local government agencies as respondents. Results: This study found that intellectual capital positively influences both internal and external collaboration as well as distribution performance. Furthermore, the current research confirms the different effect of internal collaboration and external collaboration on distribution performance; internal collaboration positively affects distribution performance, while the external one does not. Eventually, internal collaboration mediates the indirect effect of intellectual capital on distribution performance, whereas the external collaboration does not. Conclusions: This study strengthens and complements the lean stream by confirming the role of intellectual capital as critical antecedent of internal collaboration, external collaboration, and distribution performance. Moreover, this research underlines the critical role of internal collaboration as the intercourse which supports distribution performance enhancement in public sector. Lastly, the study highlights the benefits of external collaboration in distribution practice if appropriately and wisely managed.

• 한국식생활문화학회지
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• 제24권4호
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• pp.376-384
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• 2009

The purpose of the present study was to examine the relationship between personal value and the motivation for drinking of Korean undergraduate student alcohol drinkers. Data were obtained from undergraduate students experienced in alcohol consumption in Seoul, Kyeonggi-do, and Kyeongsangnam-do. Trained researchers for this particular study conducted the survey and data from 208 students was analyzed using the SPSS package program. In this study, two personal values were examined: 'internal value' and 'external value', and four motives for drinking alcohol were identified: social motive, coping motive, enhancement motive, and conformity motive. The results of the present study showed that personal value had significant effects on the motives for drinking of Korean undergraduate student alcohol drinkers: 1) The internal value was significant on the coping motive and enhancement motive. 2) The external value was significant on the social motive. 3) Neither value was significant on the conformity motive. Based on the findings of the present study, personal value would be a useful variable in the field of alcoholic beverage marketing such as alcohol consumption, consumer behaviors and segmentation of the alcoholic beverage market.

• Journal of Information Processing Systems
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• 제20권1호
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• pp.85-92
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• 2024

In recent years, Bitcoin and Ethereum have witnessed a surge in trading activity, driven by venture capital investment and funding through initial coin offerings (ICOs) and initial exchange offerings (IEOs). This heightened interest has led to kickstarting a vibrant ecosystem for blockchain development. The total number of cryptocurrencies listed on CoinMarketCap.com has reached 2,274 highlights how dynamic and wide blockchain development landscape has grown. In blockchain development, new blockchain projects are being created by forking blockchains inspired by major cryptocurrencies such as Bitcoin and Ethereum. These projects aim to address the perceived shortcomings and improve existing technologies. Altcoins, representing these alternative cryptocurrencies, are an ongoing industry effort to improve performance and security with enhancement proposals such as Bitcoin Improvement Proposals (BIP), Ethereum Improvement Proposals (EIP), and EOSIO Enhancement Proposals (EEP). With competitive attempts to improve blockchain performance and security, an ongoing performance race between various blockchains has taken shape, each claiming its own performance advantages. In this paper, we describe the transactions contained in the blocks of each representative blockchain, and find the factors that affect the transactions per second (TPS) through transaction processing and block generation processes, and suggest their relationship with scalability.