• Title/Summary/Keyword: Asymmetric Key

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Adverse Selection in the Government R&D Support for Venture Business : Evidence from the Managerial Efficiency Comparison of the Recipient and Non-recipient of R&D Grants (정부의 벤처기업 R&D 지원에서의 역선택 가능성에 관한 연구 : 정부 R&D 수혜기업과 비수혜기업 간 경영효율성 비교를 중심으로)

  • Kim, Geun-hee;Kwak, Kiho
    • Journal of Korea Technology Innovation Society
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    • v.21 no.4
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    • pp.1366-1385
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    • 2018
  • Recently, government policy focuses on R&D subsidies for venture firms in the early and medium stage. However, due to the 'asymmetric information' on those firms, a concern about the possibility of adverse selection of government policy, that is, whether the R&D subsidies are offered to the less-growth potential venture firms is on the rise. Therefore, based on the "2015 venture firm's survey" data in Korea, we compared the managerial efficiency of venture firms in manufacturing sectors by dividing them into beneficiary and non-beneficiary groups at government R&D subsidies. We found that the beneficiary groups showed lower managerial efficiency than non-beneficiary groups, even if they are superior to non-beneficiary groups in technological performance. We also observed that the phenomenon involve 'low managerial efficiency in the beneficiary groups' is more relevant in mid-high tech. manufacturing sectors. Our findings provide an exploratory empirical evidence of the concern about adverse selection in the selection of R&D subsidies beneficiary groups. Therefore, the government should consider managerial performance as the key criteria for selecting R&D subsidies beneficiary groups, rather than depending on technological performance solely. Furthermore, the government should develop other complementary policies to support financial performance of the groups. Lastly, the government should make those policies attract venture firms with potential to achieve financial performance.

Numerical Investigation of Aerodynamic Characteristics of a Ducted Fan-Vane Configuration and Improvement of Control Performance in Hover (덕트 팬-베인 형상의 제자리 비행 공력 특성 및 조종 성능 개선에 관한 수치적 연구)

  • Kang, Dong Hun;Yim, Jinwoo;You, Heung-Cheol
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.3
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    • pp.221-231
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    • 2021
  • In the present study, numerical simulation was performed to investigate aerodynamic characteristics of a ducted fan-upper/lower vanes system in hover. Sensitivity analysis of aerodynamic forces for a system component was conducted with the deflection angle of upper vanes varying but at the constant rotational speed and the collective pitch angle of fan blades. Then, vane control performance and duct airload distributions were analyzed in detail to physically understand operating mechanisms of individual vane and interference effect between duct and vanes. Finally, new control concept of operating upper vanes has been proposed to improve the control performance of the full configuration. It is found that the side force and rolling moment of upper vanes increase linearly with the variation of those deflection angle; however, the total side force is significantly small due to the reaction force acted on the duct. It is also found that upper vanes close to the duct contraction side have a key role in changing vane control forces. It is revealed that the duct suction pressure is induced by the interaction with the suction side of upper vanes, while duct pressure recovery by the interaction with the pressure side, leading to increase in duct asymmetric force. When four upper vanes are kept in situ at 0° deflection angle or removed, the total control performance was improved with duct asymmetric force reduced and the total magnitude of roll remarkably increasing up to 80%.

Study Visual Characteristics of World Cup Emblems (월드컵 엠블럼에 나타난 시각적 특징 연구)

  • YongFeng Liu
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.3
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    • pp.519-528
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    • 2023
  • The visual characteristics of the World Cup emblem play an important role in conveying culture and identity, highlighting the key elements of the Games, and strengthening the brand image. This study first investigated the visual elements and theoretical background of the emblem through previous studies. Second, the selection of symbolism, shape, and color was the subject of the study. Third, based on the shape-related theory based on the '100 National Cultural Symbols', the analysis was performed using the 'IRI Color Matching Image Scale' as a tool, and a final conclusion was drawn. The World Cup emblem uses a lot of ethnic and living symbols, and the living and ethnic symbols are expressed in a combination. In the beginning, there were many symmetric shapes, but after that it changed to an asymmetric shape. The curved expression form is more used than the straight expression form. And most of the color arrangement image scale distribution shows light, dynamic and modern color arrangement characteristics. In the future, the World Cup emblem design will continue to use national and living symbols. The shape of the emblem should use curves and asymmetric designs, be intuitive, and directly reflect the theme of the competition. In addition, the national flag color should be used as the main color, and other colors should be used as secondary colors. The combination of colors must match the light, dynamic and modern color characteristics of the IRI color scheme image scale.

Monetary Policy in a Two-Agent Economy with Debt-Constrained Households (가계부채 제약하의 통화정책: 2주체 거시모형(TANK)에서의 정량적 분석)

  • Jung, Yongseung;Song, SungJu
    • Economic Analysis
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    • v.25 no.2
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    • pp.1-53
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    • 2019
  • This paper examines monetary policy quantitatively in a two-agent and small-scale New-Keynesian economy with debt-constrained households that cannot smooth their consumption intertemporally and frictionlessly since highly indebted households are not allowed to borrow above a certain debt ceiling in incomplete financial markets without additional risk premiums due to information asymmetry between savers and borrowers. We find that, in the event of cost shocks, the asymmetric responses of borrowing households without, and saving households with, dividend incomes lead to different labor supplies and consumptions over heterogeneous households, and eventually to an extension of the monetary policy transmission channels. The income effect and low elasticity of the labor supply play key roles in such asymmetric responses over heterogeneous households. We also find that the social welfare in a flexible inflation targeting (FIT) monetary policy, in which both the inflation gap and the output gap are considered in an integrated manner when policy-making, is similar to that of the Ramsey optimal monetary policy (ROP), in which the shares of debt-constrained households, as well as all economic states, including both the inflation gap and output gap, are considered comprehensively for policy-making, and that it is greater than that of simple inflation targeting (SIT) monetary policy, in which only the inflation gap is considered mechanically for policy-making. Such social welfare implies that a FIT policy may still work even in an economy with a sizable number of debt-constrained households. Further, the responses of cost shocks to consumption and labor supply are dying out more slowly under FIT and ROP policies than under an SIT policy.

Self-aligned Offset Gated Poly-Si TFTs by Employing a Photo Resistor Reflow Process (Photo Resistor Reflow 방법을 이용한 오프셋 마스크를 이용하지 않는 새로운 자기 정합 폴리 실리콘 박막 트랜지스터)

  • Park, Cheol-Min;Min, Byung-Hyuk;Han, Min-Koo
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1085-1087
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    • 1995
  • A large leakage current may be one of the critical issues for poly-silicon thin film transistors(poly-Si TFTs) for LCD applications. In order to reduce the leakage current of poly-Si TFTs, several offset gated structures have been reported. However, those devices, where the offset length in the source region is not same as that in the drain region, exhibit the asymmetric electrical performances such as the threshold voltage shift and the variation of the subthreshold slope. The different offset length is caused by the additional mask step for the conventional offset structures. Also the self-aligned implantation may not be applicable due to the mis-alignment problem. In this paper, we propose a new fabrication method for poly-Si TFTs with a self-aligned offset gated structure by employing a photo resistor reflow process. Compared with the conventional poly-Si TFTs, the device is consist of two gate electrodes, of which one is the entitled main gate where the gate bias is employed and the other is the entitled subgate which is separate from both sides of the main gate. The poly-Si channel layer below the offset oxide is protected from the injected ion impurities for the source/drain implantation and acts as an offset region of the proposed device. The key feature of our new device is the offset lesion due to the offset oxide. Our experimental results show that the offset region, due to the photo resistor reflow process, has been successfully obtained in order to fabricate the offset gated poly-Si TFTs. The advantages of the proposed device are that the offset length in the source region is the same as that in the drain region because of the self-aligned implantation and the proposed device does not require any additional mask process step.

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Estimation of the property of small underwater target using the mono-static sonar (단상태 소나를 이용한 소형 수중표적 물성추정)

  • Bae, Ho Seuk;Kim, Wan-Jin;Lee, Da-Woon;Chung, Wookeen
    • The Journal of the Acoustical Society of Korea
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    • v.36 no.5
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    • pp.293-299
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    • 2017
  • Small unmanned platforms maneuvering underwater are the key naval future forces, utilized as the asymmetric power in war. As a method of detecting and identifying such platforms, we introduce a property estimation technique based on an iterative numerical analysis. The property estimation technique can estimate not only the position of a target but also its physical properties. Moreover, it will have a potential in detecting and classifying still target or multiple targets. In this study, we have conducted the property estimation of an small underwater target using the data acquired from the lake experiment. As a result, it shows that the properties of a small platform may be roughly estimated from the in site data even using one channel.

Mapping the Mass of the Double Radio Relic Merging Galaxy Cluster PLCK G287+32.9: A Subaru and HST Weak-lensing Analysis

  • Finner, Kyle;Jee, Myungkook James;Dawson, William;Golovich, Nathan;Gruen, Daniel;Lemaux, Brian;Wittman, David
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.41.2-41.2
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    • 2017
  • Discovered as the second highest S/N detection of the Planck SZ survey, PLCK G287.0+32.9 is a massive galaxy cluster that belongs to a rare collection of merging clusters that exhibit two radio relics and a radio halo. A feature that makes this cluster even more unique is the separation of the radio relics with one $\sim 400$ kpc to the north-west of the X-ray peak and the other $\sim 2.8$ Mpc to the south-east. This asymmetric configuration requires a complex merging scenario. A key to gaining insight into the events that caused the formation of the merging features is to understand the dark matter mass distribution. Using a weak-lensing technique on deep Subaru and Hubble Space Telescope observations, we map the dark matter mass distribution of PLCK G287.0+32.9. Our investigation detects five significant mass structures. The mass is dominated by a primary structure that is centered near the X-ray peak of the intracluster medium. Four lesser mass structures are detected with two located within $\sim 1\arcmin$ of the primary mass structure, a third to the north-west, and a fourth near the south-east radio relic. Along with these detections, we estimate the mass of each structure and relate their distributions to the intracluster medium and galaxy distributions. In addition, we discuss the relation of the mass structures to the formation of the relics and plausible merging scenarios.

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Designing Tyrosinase siRNAs by Multiple Prediction Algorithms and Evaluation of Their Anti-Melanogenic Effects

  • Kwon, Ok-Seon;Kwon, Soo-Jung;Kim, Jin Sang;Lee, Gunbong;Maeng, Han-Joo;Lee, Jeongmi;Hwang, Gwi Seo;Cha, Hyuk-Jin;Chun, Kwang-Hoon
    • Biomolecules & Therapeutics
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    • v.26 no.3
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    • pp.282-289
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    • 2018
  • Melanin is a pigment produced from tyrosine in melanocytes. Although melanin has a protective role against UVB radiation-induced damage, it is also associated with the development of melanoma and darker skin tone. Tyrosinase is a key enzyme in melanin synthesis, which regulates the rate-limiting step during conversion of tyrosine into DOPA and dopaquinone. To develop effective RNA interference therapeutics, we designed a melanin siRNA pool by applying multiple prediction programs to reduce human tyrosinase levels. First, 272 siRNAs passed the target accessibility evaluation using the RNAxs program. Then we selected 34 siRNA sequences with ${\Delta}G{\geq}-34.6kcal/mol$, i-Score value ${\geq}65$, and siRNA scales score ${\leq}30$. siRNAs were designed as 19-bp RNA duplexes with an asymmetric 3' overhang at the 3' end of the antisense strand. We tested if these siRNAs effectively reduced tyrosinase gene expression using qRT-PCR and found that 17 siRNA sequences were more effective than commercially available siRNA. Three siRNAs further tested showed an effective visual color change in MNT-1 human cells without cytotoxic effects, indicating these sequences are anti-melanogenic. Our study revealed that human tyrosinase siRNAs could be efficiently designed using multiple prediction algorithms.

Simplified elastic design checks for torsionally balanced and unbalanced low-medium rise buildings in lower seismicity regions

  • Lam, Nelson T.K.;Wilson, John L.;Lumantarna, Elisa
    • Earthquakes and Structures
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    • v.11 no.5
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    • pp.741-777
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    • 2016
  • A simplified approach of assessing torsionally balanced (TB) and torsionally unbalanced (TU) low-medium rise buildings of up to 30 m in height is presented in this paper for regions of low-to-moderate seismicity. The Generalised Force Method of Analysis for TB buildings which is illustrated in the early part of the paper involves calculation of the deflection profile of the building in a 2D analysis in order that a capacity diagram can be constructed to intercept with the acceleration-displacement response spectrum diagram representing seismic actions. This approach of calculation on the planar model of a building which involves applying lateral forces to the building (waiving away the need of a dynamic analysis and yet obtaining similar results) has been adapted for determining the deflection behaviour of a TU building in the later part of the paper. Another key original contribution to knowledge is taking into account the strong dependence of the torsional response behaviour of the building on the periodic properties of the applied excitations in relation to the natural periods of vibration of the building. Many of the trends presented are not reflected in provisions of major codes of practices for the seismic design of buildings. The deflection behaviour of the building in response to displacement controlled (DC) excitations is in stark contrast to behaviour in acceleration controlled (AC), or velocity controlled (VC), conditions, and is much easier to generalise. Although DC conditions are rare with buildings not exceeding 30 m in height displacement estimates based on such conditions can be taken as upper bound estimates in order that a conservative prediction of the displacement profile at the edge of a TU building can be obtained conveniently by the use of a constant amplification factor to scale results from planar analysis.

Comparison of Both Legs EMG Symmetry during Over-Ground Walking and Stair Walking in Stroke Patients

  • Jeong, Mu-Geun;Kim, Joong-Hwi
    • The Journal of Korean Physical Therapy
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    • v.27 no.4
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    • pp.228-233
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    • 2015
  • Purpose: Gait is the most basic element when evaluating the quality of life with activities of daily living under ordinary life circumstances. Symmetrical use of the lower extremities requires complicated coordination of all limbs. Thus, this study examined asymmetry of muscle activity quadriceps femoris and tibialis anterior as a baseline for training during over-ground walking and stair walking of stroke patients. Methods: Subjects were 14 stroke patients included as one experimental group. Gait speed used in this study was determined by the subject. Low extremity paretic and non-paretic EMG was compared using the surface EMG system. Results: The low extremity EMG difference was statistically significant during over-ground walking and stair walking (p<0.05). The result of low extremity EMG substituted symmetry ratio formula was compared to EMG symmetry ratio in both legs during over-ground walking and stair walking. The average symmetry ratio of quadriceps femoris during over-ground walking was 0.65, and average symmetry ratio of quadriceps femoris during stair walking was 0.47, with significant difference (p<0.05). Conclusion: EMG data was higher in stair walking than over-ground walking. However, in the comparison of symmetry ratio, asymmetric EMG of quadriceps femoris was significantly increased during stair walking. These findings suggested that application of stair walking for strengthening of both legs can be positive, but the key factor is maintaining asymmetrical posture of both legs. Therefore, physical therapists should make an effort to reduce asymmetry of quadriceps femoris power during stair walking by stroke patients.