• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.798-803
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• 2009

In this study, dimensionless correlations of frost properties (i.e. the thickness and surface temperature of frost) on heat exchanger fin with nonuniform temperature distribution are proposed from frosting experiments. We analyzed the local fin temperature distribution, frost thickness and frost surface temperature on a 2D fin; in the airflow direction and the direction perpendicular to airflow. As a result, the frost growth on the fin had a close relation with fin heat conduction. The dimensionless correlations for the average frost properties were expressed as a function of dimensionless temperature, humidity ratio, Reynolds number, and Fourier number. These correlations agreed well with experimental data with the error less than 14%.

• The Journal of Society for e-Business Studies
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• v.18 no.2
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• pp.241-255
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• 2013

In this study, the relationship between movie ticket reservation rates and Internet buzz share is analyzed. The correlations between movie ticket reservation rates and Internet buzz share in blogs, Internet cafes, news site, and Internet video in NAVER which is a representative Internet portal in Korea are analyzed empirically. The results show that there are positive correlations between buzz shares and movie ticket reservation rates. In particular, before movies at the box office, the correlations with Internet video is relatively higher than those of other channels, and after movies at the box office, the correlations with blogs and Internet cafe are relatively higher. Also, we can find that the correlations between Internet buzz shares on movies and movie ticket reservation rates are different depending on time lags and Internet channels.

• The Journal of Korean Physical Therapy
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• v.20 no.1
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• pp.33-40
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• 2008

Purpose: This study was designed to investigate the correlations between muscle strength of the ankle and balance, walking in the elderly. Methods: Thirty-nine subjects were selected from a population of female volunteers. Measurement of balance ability included evaluation of timed "up and go", functional reach, and a one leg standing test. Measurement of walking analysis included evaluation of cadence, stride length, step length, and walking speed. Maximal voluntary isometric contraction (MVIC) of the ankle muscle strength was measured by use of a dynamometer. Results: For balance, there were significant negative correlations between timed "up and go" and the MVIC of the ankle dorsiflexor. There were significant positive correlations between one leg standing with the eyes closed and the MVIC of the ankle dorsiflexor. For walking, there were significant positive correlations between cadence, walking speed and the MVIC of the ankle dorsiflexor. Conclusion: This study showed that there were close relationships between muscle strength of the ankle dorsiflexor and walking and balance in the elderly.

• Journal of the Korean Society of School Health
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• v.22 no.2
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• pp.125-135
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• 2009

Purpose: This study is to identify the relations between alexithymia, emotional clarification, emotional expressiveness and somatic symptoms, and their effect on the elementary school students. Methods: This study targets 567 elementary school students and they are composed of 288 boy students and 279 girl students in 5th and 6th grade, and 283 in the 5th grade and 284 in the 6th grade. Results: In somatic symptoms, alexithymia, emotional clarification, and emotional expressivness, a significant difference is found. For the somatic symptoms and alexithymia, the subject in grade 5 show higher score than those in grade 6. For the emotional clarification, and emotional expressivness, the subjects in grade 5 show higher scores than those of grade 6. According to sex, only in emotional clarification, a significant difference is found between boys and girls and the girls show higher score that the boys. In looking at the correlations between alexithymia, emotional clarification and somatic symptoms, the somatic symptoms has positive correlations with alexithymia while it has negative correlations with emotional expressiveness. The alexithymia has negative correlations with emotional clarification and emotional expressiveness. It is found that the emotional clarification has positive correlations with emotional expressiveness. Conclusion: In respect to the effect of alexithymia, emotional clarification and emotional expressiveness on somatic symptoms, emotional alexithymia and emotional clarification have effect on somatic symptoms and emotional expressiveness has no effect on somatic symptoms.

• Nuclear Engineering and Technology
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• v.46 no.2
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• pp.195-206
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• 2014

Heat transfer characteristics in a narrow rectangular channel are experimentally investigated for upward and downward flows. The experimental data obtained are compared with existing data and predictions by many correlations. Based on the observations, there are differences from others: (1) there are no different heat transfer characteristics between upward and downward flows, (2) most of the existing correlations under-estimate heat transfer characteristics, and (3) existing correlations do not predict the high heat transfer in the entrance region for a wide range of Re. In addition, there are a few heat transfer correlations applicable to narrow rectangular channels. Therefore, a new set of correlations is proposed with and without consideration of the entrance region. Without consideration of the entrance region, heat transfer characteristics are expressed as a function of Re and Pr for turbulent flows, and as a function of Gz for laminar flows. The correlation proposed for turbulent and laminar flows has errors of ${\pm}18.25$ and ${\pm}13.62%$, respectively. With consideration of the entrance region, the heat transfer characteristics are expressed as a function of Re, Pr, and $z^*$ for both laminar and turbulent flows. The correlation for turbulent and laminar flows has errors of ${\pm}19.5$ and ${\pm}22.0%$, respectively.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.1
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• pp.17-22
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• 2021

PURPOSE: This study examined the correlations between gait, static balance, and pelvic inclination in patients with chronic stroke. METHODS: Twenty-two chronic stroke patients were included in this study. The subjects participated in gait, static balance, and pelvic inclination tests. In the gait measurement, the cadence and gait velocity were measured, and the average of three trials was calculated and recorded. The static balance was measured using a force platform. The data was captured for ten seconds, and five successful trials were recorded. Pelvic inclination in the sagittal plane was measured using a palpation meter. For data processing, a KolmogorovSmirnov test was used to determine the type of distribution for all variables. Pearson's correlation coefficient was used for correlation analysis. The correlations among the gait, static balance, and pelvic inclination was calculated. The level of significance was .05. RESULTS: Significant negative correlations were observed between the gait variables (cadence, velocity) and static balance variables (COP path length, COP average velocity, and 95% confidence ellipse area) (p < .05). On the other hand, there was no significant correlation between pelvic inclination and gait or between the pelvic inclination and static balance variables. CONCLUSION: Significant correlations were observed between the gait function and static balance. On the other hand, there were no significant correlations between the pelvic inclination and gait and static balance. These results suggest that the pelvic inclination is not an important consideration for increasing the gait function and static balance.

• Nuclear Engineering and Technology
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• v.56 no.10
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• pp.4397-4403
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• 2024

The multi-dimensional thermal-hydraulic phenomena in the downcomer of advanced pressurized water reactor with direct vessel injection system are the key points for the safety analysis during a loss of coolant accident. In order to improve the accuracy of LOCUST code for the predictions of thermal-hydraulic phenomena in downcomer region, some newly correlations have been implemented into LOCUST code. The wall friction model of LOCUST code was modified based on the correlations which developed by Yang. The interfacial friction models in LOCUST code have been modified as Hibiki-Ishii correlations. In addition, in order to simulate the upward flow of recirculation flow in downcomer region, the Kinoshita-Hibiki correlations have been also implemented into LOCUST code for better simulating the recirculation flow in downcomer region. The modified code was validated with experimental data of DOBO facility. Five tests of DOBO facility have been calculated by LOCUST, and the calculated axial void fraction distributions have been compared with the measurements. The results show that the modified LOCUST with new correlations of distribution parameter and drift velocity shows better accuracy than the original code. The deviations of the modified LOCUST code are less than the original code and are almost within ±20 %.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06c
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• pp.223-228
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• 1994

We propose a novel method to incorporate temporal correlations into a speech recognition system based on the conventional hidden Markov model. With the proposed method using the extended logarithmic pool, we approximate a joint conditional PD by separate conditional PD's associated with respective components of conditions. We provide a constrained optimization algorithm with which we can find the optimal value for the pooling weights. The results in the experiments of speaker-independent continuous speech recognition with frame correlations show error reduction by 13.7% with the proposed methods as compared to that without frame correlations.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1995.06a
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• pp.87-90
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• 1995

In this paper, we propose a new deinterlacing algorithm based on weighted wide vector correlations. This algorithm is developed mainly for the format conversion problem encountered in current HDTV system, but not limited to. By having wide vector correlations, visually annoying artifacts caused by interlacing, such as a serrate line, line crawling, a line flicker, and a large area flicker, can be remarkably reduced, since the use of wide vector correlation increases the detectability of edges in various orientations.

• Journal of the Chungcheong Mathematical Society
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• v.17 no.1
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• pp.47-56
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• 2004

The nonlinearity of a Boolean function f on $GF(2)^n$ is the minimum hamming distance between f and all affine functions on $GF(2)^n$ and it measures the ability of a cryptographic system using the functions to resist against being expressed as a set of linear equations. Finding out the exact value of the nonlinearity of given Boolean functions is not an easy problem therefore one wants to estimate the nonlinearity using extra information on given functions, or wants to find a lower bound or an upper bound on the nonlinearity. In this paper we extend the notion of auto-correlations of Boolean functions to vector Boolean functions and obtain upper bounds and a lower bound on the nonlinearity of vector Boolean functions in the context of their auto-correlations. Also we can describe avalanche characteristics of vector Boolean functions by examining the extended notion of auto-correlations.