• 한국정보시스템학회지:정보시스템연구
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• 제31권1호
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• pp.115-146
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• 2022

Purpose The purpose of this study is to find meaningful insights using regression analysis to resolve the digital divide between generations. In the analysis process of this study, social network analysis was applied to approach it with a perspective differentiated from the existing statistical techniques. Design/methodology/approach This study used a social network analysis methodology that transforms and analyzes government-led survey data into relational data. First, the cross-sectional data were converted into relational data, and a continuous core-periphery model and multidimensional scaling method were applied. Afterwards, the relationship between various factors affecting the digital divide and the difference in influence were analyzed by generation. Findings According to the network analysis results, it can be seen that all generations commonly use 'information and news search' and 'living information service'. However, it can be seen that the centrally used services of each generation are clearly different from each other, and the degree of linkage between the services is also clearly different. In addition, it can be seen that the relationship between factors influencing the digital divide by generation is also different.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.7-8
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• 2006

The governing equations for high-speed lateral atomizing injector nozzle flow based on the LES-VOF model in conjunction with the CSF model are presented, and then an integrated parallel computation are performed to clarify the detailed atomization process of a high speed nozzle flow and to acquire data which is difficult to confirm by experiment such as atomization length, liquid core shapes, droplets size distributions, spray angle and droplets velocity profiles. According to the present analysis, it is found that the atomization rate and the droplets-gas two-phase flow characteristics are controlled by the turbulence perturbation upstream of the injector nozzle, hydrodynamic instabilities at the gas-liquid interface, shear stresses between liquid core and periphery of the jet. Furthermore, stable and a high-resolution computation can be attained in the high density ratio (pl/ pg = 554) conditions conditions by using our numerical method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1557-1563
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• 1991

Vendors and consultants struggle to draw attention to their proven experience in discrete CIM in order to convince process manufacturers to adopt CIM technology. The analogy works very well at the periphery where an invoice is an invoice, but disintegrates at the core where modeling of the manufacturing "process" is required. Until recently, it has not been possible to completely and rigorously model entire process plants in real-time, and this missing core element has been called the "CIM GAP" With the recent introduction of the concurrent resolution $^{sm}$ kernel, the CIM GAP now is being closed in the process industries.ntroduction of the concurrent resolution $^{sm}$ kernel, the CIM GAP now is being closed in the process industries.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1407-1424
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• 2024

In Pressurized Water Reactors, most of the failed fuel rods are often observed at the periphery of the fuel assembly, especially near the core baffle. The rod vibration-induced fretting wear is a significant failure mechanism strongly correlated with the coolant and support conditions. This paper presents a coupled vibration model of double-rod to predict the grid-to-rod fretting (GTRF) wear. A motion-dependent fluid force model is used to simulate the coolant cross flow, the gap constraints with asymmetric stiffness between spring and dimple on the vibration form, and the fretting wear are discussed. The results show the effect of the coupled vibration on the deterioration of wear, providing a sound theoretical explanation of some failure phenomena observed in the previous experiment. Exploratively, we analyze the impact of the baffle jet on the GTRF wear, which indicates that the high-velocity cross-flow will significantly affect the vibration forms while sharply changing the wear behavior.

• 경영정보학연구
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• 제25권2호
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• pp.77-101
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• 2023

코로나19 팬데믹의 영향으로 오프라인 현장콘서트의 대안적 공연형태이자 새로운 수익모델로서 유료 온라인 라이브콘서트가 등장하였으며, 계속해서 활발히 진행되어 오고 있다. 이러한 유료 온라인 라이브콘서트 참여자들의 경험에 대한 관심은 높아지고 있지만, 이들의 콘서트 소비 및 참여경험을 상세하게 분석한 연구는 드물다. 이에 본 연구는 사회표상이론(social representations theory, SRT)을 바탕으로 유료 온라인 라이브콘서트 참여자들의 소비경험에 대한 통찰력을 제공하는 것을 목적으로 한다. 특히 유료 온라인 라이브콘서트에 대한 참여자들의 경험을 바탕으로 C-P-N-D(Content-Platform-Network-Device) 모형에 기반한 유료 온라인 라이브콘서트의 특징 차원의 요소와 관람자의 인식 차원의 요소들을 탐색하고자 하며, 이를 위해 개방형 설문에 대한 239명의 응답을 바탕으로 SRT에 기반한 핵심-주변부 분석을 실시하였다. 연구결과에 따르면, 유료 온라인콘서트에 대한 총체적인 인식과 네트워크 및 기기 차원의 특징들이 유료 온라인콘서트의 핵심적 사회표상 요소로 제시되었으며, 콘텐츠와 플랫폼 차원의 요인들이 주변부 요소로 제시되었다. 본 연구의 결과는 대안적 매체로 부상하는 유료 온라인콘서트에 대한 전반적인 이해를 제고하고, 참여자들의 소비 및 관람 경험에 대한 심도 있는 이해와 이론 및 실무적 통찰력을 제공하고 있다.

• 지역연구
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• 제11권1호
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• pp.79-91
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• 1995

As an exit to solve the economic depression of the development countries in the early twentieth century, the 'old international division of labor' developed. The economic crisis(i.e., under-consumption crisis) was due to the absence of the mode of regulation compatible with the extensive regime of accumulation(i.e., "Fordist" regime). The crisis was solved by the state intervention through the creation on institutions in order to increase the level of consumption. Until the late 1960s when "high Fordism" reached(i.e., a harmonious relation between the monopoly mode of regulation and the intensive accumulation of capital), the developed core countries enjoyed a remarkable economic growth. The external market was not a necessity for the economic growth because there were increases in labor productivity and proportional increases in real wages and thus increases in consumption level. In the 1970s, however, the core faced with economic crisis again. Due to the breakdown of the postwar "Fordist" regime of capital accumulation and the post 1973 world depression, the core needed the Third World as a solution for their internal and international economic crisis. Thus the 'new international division of labor'(NIDL) arose. The "Fordist" method of production(i.e., the divisions of production process) led to the territorial division of labor and to the detailed division of labor. The aim of the NIDL is to exploit reserve armies of labor on a world scale and thus to reduce production costs. According to the NIDL model, the Third World countries have been developing by the core countries' investment on mainly labor-intensive industries and thus have been playing an important role in the global economy. And the NIDL theorists argue that multinational corporations have increasingly invested in the Third World nations and contributed to the economic growth in those regions. Tables presented in the paper show that the global trend since the 1970s does not follow the argument exactly as the NIDL theorists predicted. On the contrary, the core countries focus on developing technology, adopting the automation of production process, and trading within the core countries rather than on investing in the periopheral countries. The continuing investment of multinational corporations into the periphery is not because of cheap labor force but because of the market potentials in the regions. Majority of corporations of the core tries to reduce production costs by investing in technological development more intensively and also by changing regional strategies (i.E., investment from metropolitan areas to medium - or small - size cities, focusing on agglomeration economy, boosting regional diversification, etc.) within their own countries. The main purpose of the paper is to review and to criticize the NIDL theory based on some empirical data.IDL theory based on some empirical data.

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2881-2892
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• 2024

Annular flow refers to a special type of two-phase flow pattern in which liquid flows as a thin film at the periphery of a pipe, tube, or conduit, and gas with relatively high velocity flows at the center of the flow section. This gas also includes dispersed liquid droplets. The liquid film flow rate continuously changes inside the tube due to two processes-entrainment and deposition. To determine the liquid holdup, pressure drop, the onset of dryout, and heat transfer characteristics in annular flow, it is important to have proper knowledge of flow characteristics. Especially a better understanding of entrainment fraction is important for the heat transfer and safe operation of two-phase flow systems operating in an annular two-phase flow regime. Therefore, the objective of this work is to develop a computational model for the simulation of the annular two-phase flow regime and assess the various existing models for the entrainment rate. In this work, Computational Fluid Dynamics (CFD) in ANSYS FLUENT has been applied to determine annular flow characteristics such as liquid film thickness, film velocity, entrainment rate, deposition rate, and entrainment fraction for various gas-liquid flow conditions in a vertical upward tube. The gas core with droplets was simulated using the Discrete Phase Model (DPM) which is based on the Eulerian-Lagrangian approach. The Eulerian Wall Film (EWF) model was utilized to simulate liquid film on the tube wall. Three different models of Entrainment rate were implemented and assessed through user-defined functions (UDF) in ANSYS. Finally, entrainment for fully developed flow was determined and compared with the experimental data available in the literature. From the simulations, it was obtained that the Bertodano correlation performed best in predicting entrainment fraction and the results were within the ±30 % limit when compared to experimental data.

• 지역연구
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• 제34권3호
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• pp.43-54
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• 2018

본 논문에서는 고령화의 진행이 초래하는 산업집적 패턴의 변화에 대해 신경제지리학적 접근을 통하여 분석하였다. 은퇴인구 변수의 추가는 단기적으로 지역별 물가, 소득, 명목임금 및 실질임금에 영향을 미친다. 일반적으로 장기균형 조건으로 채택되는 지역 간 실질임금의 균등화는 은퇴인구를 고려하지 못하므로 간접효용의 균등 조건을 추가하였으며, 새로운 장기균형을 달성케 하는 최적 세액을 제시한다. 은퇴인구의 발생은 모든 지역의 실질임금을 하락시킴과 동시에 효용기준을 만족시키는 특정 지역 제조업 종사자 비율의 지점을 하락시켜 제조업의 집적을 방해하는 반면, 세금은 은퇴인구가 발생한 지역의 효용과 실질임금을 높이고 다른 지역의 효용과 실질임금을 낮춘다. 이러한 상황에서 지역 간 실질임금 및 간접효용 비율이 같아지는 제조업 인구의 비율과 세금의 조합이 존재한다. 정부가 정액세의 부과를 통해 실질임금을 적절히 조정한다면 모든 지역에서 실질임금의 급격한 하락을 막으면서 효용수준을 안정시킬 수 있다.

• Korean Journal of Radiology
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• 제23권4호
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• pp.446-454
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• 2022

Objective: To evaluate whether hyperoxia-induced ΔR₁ (hyperO₂ΔR₁) can accurately identify histological infarction in an acute cerebral stroke model. Materials and Methods: In 18 rats, MRI parameters, including hyperO₂ΔR₁, apparent diffusion coefficient (ADC), cerebral blood flow and volume, and ¹⁸F-fluorodeoxyglucose uptake on PET were measured 2.5, 4.5, and 6.5 hours after a 60-minutes occlusion of the right middle cerebral artery. Histological examination of the brain was performed immediately following the imaging studies. MRI and PET images were co-registered with digitized histological images. The ipsilateral hemisphere was divided into histological infarct (histological cell death), non-infarct ischemic (no cell death but ADC decrease), and nonischemic (no cell death or ADC decrease) areas for comparisons of imaging parameters. The levels of hyperO₂ΔR₁ and ADC were measured voxel-wise from the infarct core to the non-ischemic region. The correlation between areas of hyperO₂ΔR₁-derived infarction and histological cell death was evaluated. Results: HyperO₂ΔR₁ increased only in the infarct area (p ≤ 0.046) compared to the other areas. ADC decreased stepwise from non-ischemic to infarct areas (p = 0.002 at all time points). The other parameters did not show consistent differences among the three areas across the three time points. HyperO₂ΔR₁ sharply declined from the core to the border of the infarct areas, whereas there was no change within the non-infarct areas. A hyperO₂ΔR₁ value of 0.04 s^-1 was considered the criterion to identify histological infarction. ADC increased gradually from the infarct core to the periphery, without a pronounced difference at the border between the infarct and non-infarct areas. Areas of hyperO₂ΔR₁ higher than 0.04 s^-1 on MRI were strongly positively correlated with histological cell death (r = 0.862; p < 0.001). Conclusion: HyperO₂ΔR₁ may be used as an accurate and early (2.5 hours after onset) indicator of histological infarction in acute stroke.