• Journal of ILASS-Korea
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• v.26 no.2
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• pp.67-72
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• 2021

Rayleigh-Benard-Marangoni (RBM) convection have been artificially made for application of various engineering fields. For a relatively larger circular container, natural convection experiments were carried out to reveal and show the flow characteristics with engine oil (SAE30) using IR camera. IR camera has captured the temperature distribution on the free surface. From these experiments, it was confirmed that it was possible to quantitatively analyze the occurrence characteristics of RBM flow clearly from the thermal images taken with IR camera. As the aspect ratio increased, both the number of internal and external cavities increased. And found that the criteria of RBM flow generation proposed through previous experiments performed for small-sized containers are also very effective with the results on larger circular container.

• Journal of the Korean Society for Library and Information Science
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• v.18
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• pp.55-98
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• 1990

This research attempts to verify the hypothesis that the workers in the small-and medium-sized industries use more informal information channels than formal ones do to get the information necessary to industrial activities. Information sources are divided by the internal and the external ones and these are sub-divided by their acquiring channels, publishers and holding institutions. It is intended to investigate the information sources according to the use frequency, age, origin and format of documents used. The degree of benefit to the workers in their practical work through the use of information sources and the use frequency of information sources by the department and years of experience are also investigated. The data to test the hypothesis was collected through the questionnaires distributed to the workers in 300 sampled firms from June 5 to June 20, The following facts have been verified as the result : 1. Workers in industries acquire information mainly through the contacts with the colleagues or superiors in their departments, and the junior workers depend more on the colleague and superiors than senior workers are. 2. Among the documents published internally, the ones from the research and development departments are mostly used. The documents issued by the worker's own departments are also frequently used and the senior workers, the more frequently use the internal publications than the junior workers do. 3. Among the internal documents stored in various places in the industries, the documents kept in the worker's own departments are used most frequently. The senior workers the more use privately owned documents than the junior workers do. 4. As far as the external channels are concerned, information is obtained mainly through suppliers of equipment and raw materials and the use frequency of information channels varies according to department. The senior workers the more receive information through supporting institution, seminar and exhibition than the junior workers do. 5. Among the external publication, the ones published by the industrial supporting institutions are heavily used and the workers in research and developments frequently use the external publications. 6. The documents held in governmental industrial institutions and industrial supporting institutions are heavily used compared with the ones stored in other external institutions. The holding places of frequently used documents vary according to the working departments. 7. The degree of benefit to practical work performance resulted from the internal information use is less than by the use of external information. 8. The documents published more than five years ago are more used than the ones of less than five years, Korean and Japanese documents are used frequently and catalogues, patents and standards are used to a great extent. The documents are used differently in accordance with work departments.

• Wind and Structures
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• v.16 no.1
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• pp.1-23
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• 2013

The wind-induced transient response of internal pressure following the creation of a sudden dominant opening during the occurrence of high external pressure, in low-rise residential and industrial buildings was numerically investigated. The values of the ill-defined parameters namely the flow contraction coefficient, loss coefficient and the effective slug length were calibrated by matching the analytical response with the computational fluid dynamics predictions. The effect of a sudden i.e., "instantaneously created" windward opening in the Texas Technical University (TTU) test building envelope was studied for two different envelope flexibility-leakage combinations namely: (1) a quasi-statically flexible and non-porous envelope and (2) a quasi-statically flexible and porous envelope. The responses forced by creating the openings at different time leads/lags with respect to the occurrence of the peak external pressure showed that for cases where the openings are created in close temporal proximity to the peak pressure, the transient overshoot values of internal pressure could be higher than the peak values of internal pressure in the pre-sequent or subsequent resonant response. In addition, the influence of time taken for opening creation on the level of overshoot was also investigated for the TTU building for the two different envelope characteristics. Non-dimensional overshoot factors are presented for a variety of cavity volume-opening area combinations for (1) buildings with rigid/quasi-statically flexible non-porous envelope, and (2) buildings with rigid/quasi-statically flexible and porous envelope (representing most low rise residential and industrial buildings). While the factors appear slightly on the high side due to conservative assumptions made in the analysis, a careful consideration regarding the implication of the timing and magnitude of such overshoots during strong gusts, in relation to the steady state internal pressure response in cyclonic regions, is warranted.

• The Korean Journal of Nuclear Medicine
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• v.8 no.1_2
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• pp.1-11
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• 1974

The author in an attempt to evaluate hemodynamic changes in the clinical stages of Korean hemorrhagic fever measured plasma volume, cardiac output and effective renal plasma flow utilizing radioisoto es during various phases of the disease. Cardiac output was measured by radiocardiography with external monitoring method using RIHSA. Effective renal plasma flow was obtained from blood clearance curve drawn by external monitoring after radiohippuran injection according to the method described by Razzak et al. The study was carried out in thirty-eight cases of Korean hemorrhagic fever and the following conclusions were obtained. 1. Plasma volume was increased in the patients during the oliguric-and hypertensive diuretic phases, while it was normal in the patients during the normotensive-diuretic phase. 2. Cardiac index was increased in the patients during the oliguric phase and was slightly increased in the patients at the hypertensive diuretic phase. It was normal in the other phases. 3. Total peripheral resistance was increased in the hypertensive patients during diuretic phase, while it was normal in the rest of phases. 4. Effective renal plasma flow was significantly reduced in the patients during the oliguric and diuretic phases as well as at one month after the oliguric onset. There was no significant difference between the oliguric and the early diuretic phases. Renal plasma flow in the group of patients at one month after the oliguric onset was about 45% of the normal, however, it returned to normal level at six months after the onset. 5. Clinical syndrome of relative hypervolemia was observed in some patients during the oliguric phase or hypertensive diuretic phase. Characteristic hemodynamic findings were high cardiac output and normal to relatively increased peripheral resistance in these cases. Relatively increased circulating blood volume due to decreased effective vascular space was suggested for the mechanism of relative hypervolemia. 6. Cardiac hemodynamic alteration returned to normal during late stage of the diuretic phase, while renal hemodynamic changes were normalized at six months after the onset.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.3017-3029
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• 2023

In the late in-vessel phase of a nuclear reactor severe accident, the internal heat transfer and crust evolution during the debris bed melting process have important effects on the thermal load distribution along the vessel wall, and further affect the reactor pressure vessel (RPV) failure mode and the state of melt during leakage. This study coupled the phase change model and large eddy simulation to investigate the variations of the temperature, melt liquid fraction, crust and heat flux distributions during the debris bed melting process in the hypothetical severe accident of HPR1000. The results indicated that the heat flow towards the vessel wall and upper surface were similar at the beginning stage of debris melting, but the upward heat flow increased significantly as the development of the molten pool. The maximum heat flux towards the vessel wall reached 0.4 MW/m². The thickness of lower crust decreased as the debris melting. It was much thicker at the bottom region with the azimuthal angle below 20° and decreased rapidly at the azimuthal angle around 20-50°. The maximum and minimum thicknesses were 2 and 90 mm, respectively. By contrast, the distribution of upper crust was uniform and reached stable state much earlier than the lower crust, with the thickness of about 10 mm. Moreover, the sensitivity analysis of initial condition indicated that as the decrease of time interval from reactor scram to debris bed dried-out, the maximum debris temperature and melt fraction became larger, the lower crust thickness became thinner, but the upper crust had no significant change. The sensitivity analysis of in-vessel retention (IVR) strategies indicated that the passive and active external reactor vessel cooling (ERVC) had little effect on the internal heat transfer and crust evolution. In the case not considering the internal reactor vessel cooling (IRVC), the upper crust was not obvious.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.789-796
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• 2003

A reliability analysis is performed to investigate the influence of the uncertainty from the limited in-situ samples and the inherent heterogeneity of the ground on the probability of piping for the marine embankment near shore. The result are compared with those of the deterministic piping stability analysis performed using the fininte element flow analysis. The random variables used are hydraulic conductivity of the ground subsurface and embankment, and the water level of both internal and external side of the embankment. The probability of piping is most sensitive to the mean and standard deviation of internal water level of the embankment among the random variables included in the reliability analysis. It is found that the lower limits of internal water level which satisfies the allowable proability of piping failure for the embankment studied were E.L(-) 1.83m and E.L(-) 1.48m during and after the construction of the embankment, respectively.

• International Journal of Advanced Culture Technology
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• v.12 no.1
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• pp.75-84
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• 2024

The novel literature of the Romantic era was characterized by emotionally charged and imaginatively rich works. During this period, authors brought a new flow to the literary scene by exploring romantic themes in their unique styles. Various themes and genres emerged, diversifying the novel's target audience. It was during this era that Emily Brontë's "Wuthering Heights" was published. In this paper, we aim to explore the theme of alleviating internal turmoil within this novel, focusing on one enigmatic character, Heathcliff, among the main protagonists. We will illuminate Heathcliff's tumultuous past, analyzing the intricate connections of events that led to profound psychological anguish. By scrutinizing his actions and outward expressions, this paper seeks to understand the manifestation of his internal pain in interactions with other characters. We present a more comprehensive understanding of "Wuthering Heights," transcending the conventional boundaries of literary analysis. It not only proposes practical methods for alleviating internal turmoil but also sheds light on the timeless theme of divine love, offering readers a profound framework for interpreting the complexities of human relationships and the pursuit of inner peace.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.9
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• pp.15-23
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• 2020

Spline is a machine component using transmits rotating energy with grooves on internal of boss and external periphery of shaft. Internal spline is generally produced by machining process. However, to reduce manufacturing cost and save time, plastic deformation process such as backward extrusion is gradually adapted for spline production. In plastic deformation process, forming load, stress on tools and flow flaws should be taken into account to have sound products. For this purpose, kinematically admissible velocity fields for Upper Bound Method in backward extrusion of internal spline has been suggested, then forming load and relative pressure have been calculated. Internal spline forming experiments have been con-ucted under hydraulic press and the calculated forming load well predicts the load of experiment.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.12
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• pp.1635-1646
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• 1997

The nozzle length to diameter ratio of real diesel nozzles is about 2-8 which is not long enough for a fully developed and stabilized flow. The characteristics of the flow such as turbulence at the nozzle exit which affect the development of the spray can be enhanced by impinging the flow inside nozzle. The flow details inside the impinging nozzles have been investigated both experimentally and numerically. The mean velocities, the fluctuating velocities, and discharge coefficients in the impinging inlet nozzles, round inlet nozzle, and sharp inlet nozzle were obtained at various Reynolds number. The developing feature of the external spray were photographed by still camera and the droplet sizes and velocities were also measured by laser Doppler technique. The spray angle was greater and the droplet sizes near the spray axis were smaller with the impinging flow inside nozzle.

• IE interfaces
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• v.10 no.3
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• pp.189-196
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• 1997

This paper presents a cell formation approach for a cellular manufacturing system to minimize the inter-cell moves considering operation sequences. Two new factors are introduced: (1)flow-similarity(FS) for integrating direct/indirect inter-machine flow and similarity (2)machine cell-part moves (CPM) for exactly computing inter-cell moves. FS is used for combining machines and CPM is used for assigning the parts to the preliminary machine cells. In addition, we develop an aggregated heuristic algorithm to form manufacturing machine cells and assign the parts to those cells based on these concepts. We use performance criterion called total inter-cell moves(TICM), which is the total material flow between internal cells and external cells. Results of computational tests on a number of randomly generated test problems show that the suggested heuristic is superior to existing methods.