• Title/Summary/Keyword: imperfect

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A study on the effect of SME IT resource on performance (중소기업의 IT자원이 업무성과에 미치는 영향에 관한 연구)

  • Jin, Jeongsuk;Park, Jooseok;Park, Jaehong
    • The Journal of Bigdata
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    • v.4 no.2
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    • pp.141-158
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    • 2019
  • Based on RBV(Resource Based View), IT of SMEs classified into IT resource and capabilities. And We confirmed that capabilities and resources affected each performance. In other words, based on the questionnaire of SMEs and IT professionals, divides capability from the overall IT resource that are possessed by SMEs. Among the four attributes (value, rare, non-substitutability, imperfect imitability) presented by Barney (1991), this study targeted at value and imperfect imitability and investigated how SMEs recognize IT resource and capability. Furthermore, this study tests how IT resource and capability influence corporate performance. The result of this study finds that resources that are needed on "Knowledge-based" are classified into IT capability, otherwise classified into IT resource. Analysis shows that server, DB(database), system administrators, programmers, CIO, BA were capabilities, Desktop PC, PC software, software for salary and accounting management, e-commerce, Homepage, and network inside th enterprise were resources. Secondly, this study reveals that both IT resource and IT capability affected company performance (employee satisfaction, CEO satisfaction). IT is certainly having an impact on corporate performance. In conclusion, resource can be either IT resource or IT capability based on they way of utilization. And both IT resource and IT capability have an influence on corporate performance (employee job satisfaction, CEO satisfaction). Therefore, when considering IT investment, a company can purchase necessary IT resource and actively utilize it to be IT capability, which can have an influence on corporate performance in return.

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The Study on the Properties of Polypropylene/Nylon6 with Various Compatibilizers (Polypropylene/Nylon6 블렌드에서 이종의 상용화제에 따른 물성연구)

  • Kim, H.C.;Lee, K.Y.;Kim, H.I.
    • Applied Chemistry for Engineering
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    • v.10 no.4
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    • pp.497-501
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    • 1999
  • The changes of properties were studied for the polypropylene(PP)/Nylon6 blends containing different kinds of compatibilizer made by either reactive extrusion of solution reaction. The compatibilizers were PP grafted with maleic anhydride (MAH) made by reactive extrusion and solution reaction. The grafted MAH contents were 0.3 wt %, and 2.7 wt %, respectively. The composition of the PP/nylon6 blend was fixed at 75/25 by weight. Blending was carried out with twin-screw extruder (L/D=30, ${\psi}=30$) at 300 rpm. As the content of PP-g-MAH was increased, the crystallization peak of Nylon6 decreased gradually then finally disappeared. Disappearance of crystallization peak of Nylon6 was mostly affected by grafted MAH content rather than the preparation method and the amount of compatibilizer. The portion of Nylon6 that could not crystallize in its normal crystallization temperature crystallized together with PP at the crystallization temperature of PP. So called concurrent crystallization was observed. Meanwhile two more peaks were observed during heating cycle. One was exothermic peak at $193^{\circ}C$ near to crystallization temperature of Nylon6, the other was endothermic peak at $215^{\circ}C$ that was $5^{\circ}C$ lower than normal endothermic peak of Nylon6. To analyze the peaks, nylon6 was annealed in the differential scanning calorimeter. As a result, the peak at $193^{\circ}C$ was crystallization peak of imperfect crystalline of Nylon6 and the other peak at $215^{\circ}C$ was melting peak of imperfect crystalline of nylon6.

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The study on the capacity of synchronous CDMA return link for a Ka band satellite communication system (Ka 대역을 사용하는 동기화 CDMA 위성 시스템 리턴링크의 수용용량에 관한 연구)

  • 황승훈;이용한;박용서;황금찬
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.7
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    • pp.1797-1806
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    • 1998
  • Future satellite communication systems will be developed at Ka-band (20/30 GHz) owing to the relatively wide frequency allocation and current freedom from terrestrial interference for multimedia services. A serious disadvantage of the Ka-band, however, is the very high atmospheric attenuation in rainy weather. Synchronous CDMA drastically redces the effect of self-noise with several interesting features of CDMA for mobile communications such as fixible freuqncy rese, the capability of performin soft-handover and a lower sensitivity to interference. This paper evaluates the performance of a synchronous CDMA reture link for a Ka-band geostationary satellite communication system. For a fixed satellite channel whose characteristics depend on weather conditions, the signal envelope and phase for this channel is modelled as Gaussian. The bit error and outage probability, and the detection loss due to imperfect chip timing synchronization is analytically evaluated and the system capacity degaradation due to the weather condition is estimated. The two cases consist of the general case in which all users are affected by rain condition, and the worst case in which the reference user is only affected by rain attenuation. the results for two cases of rain condition clearly show that synchronous CDMA eases the power control requirements and has less sensitivity to imperfect power control.

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Erlang capacity for the reverse link of an imperfect power controlled DS/CDMA cellular system in multipath fading environments (다중경로 페이딩 환경에서 불완전 전력제어된 DS/CDMA 셀룰라 시스템의 역방향 링크에 대한 얼랑용량)

  • Kim, Hang-Rae;Kim, Nam
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.37 no.5
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    • pp.1-9
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    • 2000
  • In this paper, for the reverse link of a imperfect power controlled DS/CDMA cellular system when a mobile radio channel is a Rayleigh distributed multipath fading channel, A extended DS/CDMA blocking probability formula considering both shadowing and multipath fading is derived. Erlang capacity and equivalent channel number considering shadowing are analyzed and compared with those considering both shadowing and multipath fading, respectively. The DS/CDMA blocking probability is calculated based on the analysis method that obtains Erlang capacity and ICF(interference correction factor) using the median value of $E_{b(i)}$/ $I_{0}$ corresponding to each reverse link user Assuming that the blocking probability set 2%, it is observed that the Erlang capacity is 19.97 Erlang at the data rate $R_{b}$=9.6 kbps and 11.67 Erlang at the data rate $R_{b}$=14.4 kbps and then is less 16% and 19% than the Erlang capacity considering shadowing only, respectively. It is also shown that the effect of multipath fading must not be ignored and then exact Erlang capacity and equivalent channel numbers that the DS/CDMA cellular system can support are provided.d.d.d.

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Performance Improvement of Asunchronous DS-CDMA Systems with a Multistage Interference Canceller in the Presence of Timing and Phase Errors (칩 동기 에러와 위상 에러가 존재하는 환경에서 다단 간섭제거기에 의한 비동기 DS-CDMA 시스템의 성능 개선)

  • 김봉철;강근정;오창헌;조성준
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.1
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    • pp.1-10
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    • 2001
  • In this paper, a multistage parallel interference canceller (MPIC) and a partial multistage parallel interference canceller (PMPIC) are employed as a technique for improving the performance of the asynchronous DS-CDMA systems. The degree of the effect of the timing errors and phase errors on the interference cancellation capability of two types of cancellers is theoretically analyzed and the computer simulation is performed to confirm the analytical results. From the results, the large performance improvement is obtained by employing MPIC and PMPIC with perfect synchronization over the conventional matched filter, and the performance improvement obtained by MPIC and PMPIC is very close to each other as the number of the stage of MPIC and PMPIC increases. When the timing errors and phase errors are considered (in the case of imperfect synchronization), the performance improvement reduces as the performance degradation at the first stage (no cancellation) has a bad effect on the decision statistics at each stage. However MPIC and PMPIC have the strong interference cancellation capability in spite of imperfect synchronization as the number of the stage increases. An interference canceller, which has the strong interference cancellation capability as well as lower complexity for the implementation, is needed for practical systems with timing errors and phase errors because the perfect synchronization is impossible. Therefore, the excellent tradeoff between complexity and performance offered by PMPIC makes it an attractive approach for practical systems.

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Erlang Capacity for the Reverse Link of a IS-95 Cellular System According to Approximation Method in Shadowing Channel (전파음영 채널에서 근사방법에 따른 IS-95 셀룰라 시스템의 역방향 링크에 대한 얼랑 용량)

  • Park, Young;Kim, Hang-Rae
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.10
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    • pp.3210-3218
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    • 2000
  • In a IS-95 cellular systm, blocking will occur when the reverse link user interference power reaches a predepermmed level which is set to maintam acceptable signal quality. In this paper, it is assumed that a mobile rdio channel is a shadowing channel and Erlang capacity is calculated for the reverse limk of an imperfect power controlled IS-95 cellular system. the blocking probability is derived using lognornal pproximation and the results according to guassian and lognormal approximation method are compared and analyzed respcctively. Assuming that blocking probability is 1% at the data rate of $R_b$=9.6kbps and $R_b$=14.4kbps, it is shown that Erlang capacity using Iognormal approximation is 13.68 Erlang and 7.08 Erlang and then the approximation erroris occurred about 24.4% and 40.4% inthe garssian approximation, respectively. It is also observed that if the power control becomes periect, the Erlang capacity is increased more 6.99 and 4.21 Erlang than that of the imperfect power control that the power contrl error is 2.5dB, and if voice activity is considered as 10%, the Erlang capacity is increased more 8.21 and 1.25 Erlang than that using non voice activity, respectively.

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Originating Mobility Service Brand Baedal Minjok (배달의민족과 모빌리티 서비스 브랜드의 오리지네이션)

  • Dongpyo Hong;Jae-Youl Lee
    • Journal of the Economic Geographical Society of Korea
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    • v.25 no.4
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    • pp.641-656
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    • 2022
  • This article investigates how Baedal Minjok(BaeMin) has grown to be a dominant mobility platform operator in food delivery sector in South Korea and what roles its brand and branding have played in the process, drawing on the idea of origination. For the purpose, BaeMin is considered as a typical platformized mobility service provider and origination is framed to be an appropriate analytical lens for the business sector. For the origination conception, unlike mainstream neoclassical theory and concepts, is able to deal fairly well with the issues of imperfect competition, imperfect information, and monopolistic brand rent, which are apparent in today's platformized mobility services. Drawing evidence from textual data, empirical analysis pays particular attention to discursive and symbolic dimensions of BaeMin's socio-spatial biography. It is found that national origination underpinning ethnicity comprises an important pillar of BaeMin's brand and branding. Another form of place-based origination is also observed to matter, especially in the varied relation between the mobility service brand's owner and consumers. However, this configuration of BaeMin's brand origination has yet to be fully stabilized, as it has faced with serious challenges including brand vandalism and anti-brand movement especially since its merger to German food delivery platform giant Delivery Hero in 2020. This origination crisis moment appears to be associated with a series of contractions intrinsic to so-called 'platform capitalism'.

Identifying the Cause of Speculative Investment in Cryptocurrency Investment: Based on the Theory of Bounded Rationality (암호화폐 투자에서 투자자들의 투기적 행동을 야기하는 원인 규명: 제한된 합리성 이론을 기반으로)

  • Eunyoung Kim;Byungcho Kim
    • Information Systems Review
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    • v.22 no.1
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    • pp.33-57
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    • 2020
  • Although cryptocurrency which can promote innovation in the blockchain ecosystem is published for many useful purposes, in Korea, cryptocurrency is recognized only as a means of investment for the profit. The fact emphasizes only the speculative nature of the cryptocurrency, so investor negates the fundamental purpose of cryptocurrency and hinders innovation in the blockchain ecosystem. The purpose of this study is to investigate the cause of cryptocurrency perception and speculative behavior of domestic cryptocurrency investors from an academic perspective. We use a model that reflects the traditional considerations and cryptocurrency's characteristics in investment. Using the model, we can explain the cause of misperception of cryptocurrency through the theory of bounded rationality. In building the research model, we use variables of venture and angel investor's consideration used in investment decisions and collect the keywords from indexes of whitepaper to reflect the properties of cryptocurrency. This study mentions that, due to the imitations presented by Simon, individuals are forced to perceive cryptocurrency as a means of speculation and to make irrational decisions that impair ecosystem health. We analyze whether there is a significant difference in rationality in decision made by the sample under limited knowledge and imperfect information constraints. As a result, imperfect information constraints led investors to consider only irrational criteria in decision making. From this result, this study suggests that information asymmetry needs to be relaxed so that investment can be pursued together with rational investment and development of blockchain ecosystem. In addition, the industry can capture strategic insights for successful financing through ICO by enabling better understanding of investor decision-making.

Spatial Resolution Enhancement with Fiber - based Spectral Filtering for Optical Coherence Tomography

  • Choi, Eun-Seo;Na, Ji-Hoon;Lee, Byeong-Ha
    • Journal of the Optical Society of Korea
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    • v.7 no.4
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    • pp.216-223
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    • 2003
  • We report a technique that improves the spatial resolution of optical coherence tomography (OCT) by utilizing fiber-based spectral filtering. The proposed technique improves the resolution by filtering out the erbium’s characteristic peak from the amplified spontaneous emission (ASE) source spectrum, and reshaping the spectrum to Gaussian-like. We used a long period fiber grating (LPG) and an erbium doped fiber (EDF) absorber for the spectral filtering. An in-house made ASE source as well as a commercial ASE source [ASE-FL7002] was used as the OCT sources to study the proposed technique. The resolution of the OCT based on an in-house made ASE source is enhanced from 200 to 40 ㎛ with an LPG. While, the resolution of the OCT based on a commercial ASE source is enhanced from 25 to 19 ㎛ with the aid of an EDF absorber. However, sidelobes still exist in the interferogram due to imperfect spectral filtering, which limited the resolution. Further enhancement in the spatial resolution of the OCT system using the ASE source is possible with the aid of cascaded LPGs and/or carefully designed EDF absorber.

A Study on the Characteristics of Nonlinear Unstable Phenomenon According to the Shape Variation of Cable Domes (케이블 돔 구조물의 형태 변화에 따른 비선형 불안정 거동의 특성에 관한 연구)

  • Kim, Seung Deog;Back, In Seong;Kim, Hyung Seok
    • Journal of Korean Society of Steel Construction
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    • v.16 no.3 s.70
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    • pp.345-353
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    • 2004
  • One of the key issues in spatial structures with large spaces is how to carry the weight of the roof. This can be solved by the effective use of tension members. A cable dome structural system facilitates the construction of a large space structure. As external load increases, however, the cable dome structural system is put at risk due to global buckling. This study measures the shape of the Geiger and Flower-type cable dome by applying an initial stress. This unstable phenomenon is also examined using a perfectly shaped model and an imperfect model, which are both subjected to an axisymmetric load.