• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.1-8
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• 2006

We suggest a graphical representation of the tension flow in tonal music using a piecewise parametric curve, which is a function of time illustrating the changing degree of tension in a corresponding chord progression. The tension curve can be edited by using conventional curve editing techniques to reharmonize the original music with reflecting the user's demand to control the tension of music. We introduce three different methods to measure the tension of a chord in terms of a specific key, which can be used to represent the tension of the chord numerically. Then, by interpolating the series of numerical tension values, a tension curve is constructed. In this paper, we show the tension curve editing method can be effectively used in several interesting applications: enhancing or weakening the overall feeling of tension in a whole song, the local control of tension in a specific region of music, the progressive transition of tension flow from source to target chord progressions, and natural connection of two songs with maintaining the smoothness of the tension flow. Our work shows the possibility of controlling the perceptual factor (tension) in music by using numerical methods. Most of the computations used in this paper are not expensive so they can be calculated in real time. We think that an interesting application of our method is an interactive modification of tension in background music according to the user's emotion or current scenario in the interactive environments such as games.

• Journal of Korean Society on Water Environment
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• v.36 no.6
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• pp.521-534
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• 2020

In this study, the variation of water quality was analyzed for six sites in major tributaries of the Nakdong River Basin. Standard-FDC (Flow Duration Curve) was developed using PM (Percentile Method), one of the statistical FDC estimation methods. The LDC (Load Duration Curve) was obtained using the developed FDC. The current method and the LDC evaluation method were compared and analyzed to evaluate the achievement of TWQ (Target Water Quality). Regarding the monthly flow rate variation, the five sites showed the distribution of the lowest flow rate between May and June, indicating a high probability of dry weathering of the streams. The variation of water quality confirmed the vulnerable timing of flow rate in each site, and it is therefore deemed necessary to plan to reduce T-P and TOC. A comparison and evaluation of TWQ showed that there was a difference between the TWQ values achieved by the two techniques. In addition, the margin ratio to the 50% excess ratio can be found in the LDC evaluation. The results of the LDC evaluation by section and by month showed whether or not the water quality was exceeded by flow conditions, along with the vulnerable sections and timing. Accordingly, it is judged that this method can be used for water quality management in TMDLs (Total Maximum Daily Loads).

• Water for future
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• v.51 no.5
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• pp.47-52
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• 2018

• 산업보건소식
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• no.16
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• pp.13-19
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• 1985

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.161-166
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• 2003

It is the common features of the integral reactors that the main components of the RCS are installed within the reactor vessel, and so there are no any flow pipes connecting the coolant pumps or steam generators. Due to no any flow pipes, it is impossible to measure the differential pressure at the RCS of the integral reactors, and it also makes impossible measure the flow-rate of the reactor coolant. As a alternative method, the method by the measurement of coolant pump power has been introduced in this study. Up to now, we did not found out a precedent which the coolant pump power is used for the real-time flow-rate calculation at normal operation of the commercial nuclear power plants. The objective of the study is to embody the real-time flow-rate calculation method by the measurement of coolant pump power in an integral reactor. As a result of the study, we could theoretically reason that the capacity-head curve and capacity-shaft power curve around the rated capacity with the high specific-speeded axial flow pumps have each diagonally steep incline but show the similar shape. Also, we could confirm the above theoretical reasoning from the measured result of the pump motor inputs, So, it has been concluded that it is possible to calculate the real-time flow-rate by the measurement of pump motor inputs. In addition, the compensation for a above new method can be made by HBM being now used in the commercial nuclear power plants.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1446-1453
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• 2021

In the past, several experimental investigations aiming at characterizing the natural circulation (NC) behavior in test facilities were carried out. They showed a variety of flow patterns characterized by an inverted U-shape of the NC flow curve versus primary mass inventory. On the other hand, attempts to reproduce such curves using thermal-hydraulic system codes, showed 10-30% differences between the measured and calculated NC mass flow rate. Actually, the used computer codes are generally based upon nodalization using single U-tube representation. Such model may not allow getting accurate simulation of most of the NC phenomena occurring during such tests (like flow redistribution and flow reversal in some SG U-tubes). Simulations based on multi-U-tubes model, showed better agreement with the overall behavior, but remain unable to predict NC phenomena taking place in the steam generator (SG) during the experiment. In the current study, the CATHARE code is considered in order to assess a NC characterization test performed in the four loops PKL facility. For this purpose, four different SG nodalizations including, single and multi-U-tubes, 1D and 3D SG inlet/outlet zones are considered. In general, it is shown that the 1D and 3D models exhibit similar prediction results up to a certain point of the rising part of the inverted U-shape of the NC flow curve. After that, the results bifurcate with, on the one hand, a tendency of the 1D models to over-predict the measured NC mass flow rate and on the other hand, a tendency of the 3D models to under-predict the NC flow rate.

• Journal of Korean Society on Water Environment
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• v.36 no.6
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• pp.489-499
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• 2020

Effective science-based management of the basin water resources requires an understanding of the characteristics of the streams, such as the baseflow discharge. In this study, the base flow was estimated in the two watersheds with the least artificial factors among the Nakdong River watersheds, as determined using the chemical hydrograph separation technique. The 16-year (2004-2019) discontinuous observed stream flow and electrical conductivity data in the Total Maximum Daily Load (TMDL) monitoring network were extended to continuous daily data using the TANK model and the 7-parameter log-linear model combined with the minimum variance unbiased estimator. The annual base flows at the upper Namgang Dam basin and the upper Nakdong River basin were both analyzed to be about 56% of the total annual flow. The monthly base flow ratio showed a high monthly deviation, as it was found to be higher than 0.9 in the dry season and about 0.46 in the rainy season. This is in line with the prevailing common sense notion that in winter, most of the stream flow is base flow, due to the characteristics of the dry season winter in Korea. It is expected that the chemical-based hydrological separation technique involving TANK and the 7-parameter log-linear models used in this study can help quantify the base flow required for systematic watershed water environment management.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.1
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• pp.75-84
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• 2000

Performance and flow characteristics of a small forward swept propeller fan for home refrigerators are studied experimentally. An unusual discontinuity is observed in the performance curve of the fan. Mean flow fields measured with as-hole Pitot probe reveal that the flow is axial at the high flow rate and radial at the low flow rate. The flow structure changes abruptly across the discontinuity. Unsteady flow measurements with a set of hot-wire probes indicate that near the discontinuity a single-cell stall rotates at 40% speed of the fan speed, while away from the discontinuity the flow shows periodic variation corresponding to the blade passage frequency. Phase-lock averaged flow fields measured with a triple-sensor hot-wire probe show that there appears radially inward flow over the pressure side of the blade and the outward passage flow over the tip.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.3
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• pp.448-457
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• 2002

Heat treatment such as quenching of a high-temperature cylinder is being used on steel to produce high strength levels. Especially, the mist cooling with the high and uniform surface heat flux rate s expected to contribute for better products. The experimental mist cooling curve is produced for better understanding, and two distinct heat transfer regions are recognized from the cooling curve produced. It is shown that the liquid film evaporation dominated region follows the film boiling-dominated region as decreasing the temperature of test cylinder by mist flow. Based on the intuitive view from some previous investigations, a simplified model with some assumptions is introduced to explain the mist cooling curve, and it is shown that the estimation agrees well with our experimental data. In the meanwhile, it is known that the wetting temperature, at which surface heat flux rate is a maximum, increases with mass flow rate ratio of water to air ($\varkappa$ < 10). However, based on our experimental data, it is explained that there exists a critical mass flow rate ratio, at which the wetting temperature is maximum, in the range of 3 < $\varkappa$ < 130. Also, it is described that despite of the same value of $\varkappa$, the wetting temperature may increase with mist velocity.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.1
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• pp.50-57
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• 2001

The thermal performance of cooling towers is affected by the temperature of inlet water, wet bulb temperature of entering air and water-air flow rate. In this stud${\gamma}$, the effects of these variables are simulated using NTU-method and experimentally investigated for the counter-flow cooling towers. The simulation program to evaluate these variables which affect the performance of cooling tower was developed. The maximum errors between the results of simulations and experiments were 3.8% under the standard design conditions and 5.4% under the other conditions. The performance was increased up to 46~50% as the water loading was increased from 6.8$m^3/hr{\cdot}m^2$ to 159$m^3/hr{\cdot}m^2$. The range was reduced up to 56~42% when the wet bulb temperature of the entering air was increased from 22${\circ}C$ to 29${\circ}C$.