• Fire Science and Engineering
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• v.31 no.1
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• pp.36-41
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• 2017

In this study, the experimental measurements from a one-way moving experiment showed that the average movement speed was 0.55 m/s with an average crowd density of $2.36P/m^2$ in a corridor. The cCalculation result of the correlations between the crowd density and movement speed from the SFPE Handbook showed an average of 0.53 m/s. The difference between the calculation and experiment was 0.02 m/s. A comparison of each data set showed that the maximum difference was 0.38 m/s. Some experimental results showed that the crowd density increased with increasing movement speed and the average data from the entire experiment time was used for the analysis. When the short time interval for frame by frame analysis for video files was conducted, the experimental data was expected to be more reliable.

• Journal of radiological science and technology
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• v.24 no.1
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• pp.5-9
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• 2001

Over-density of pancreatic duct tail part on the endoscopic retrograde pancreatogram results from patient's position and inserted air during the study. The aim of this paper is to decide the filter angle to obtain an uniform density. Endoscopic retrograde pancreatography was performed to 234 patients, and angled wedge filter was used differently. They are $10^{\circ}$ (47), $20^{\circ}$ (45), $30^{\circ}$ (50), and $40^{\circ}$ (50). We also did not use wedge filter to 42 patients. We decided reliance degree in 95%. The statistical difference was p<0.05. The patients' sex rate was 1.8 : 1 between 18 and 87 years old(average age 58 years). Their body girth was 18.71 cm on the average. Of total 234 patients, difference of right and left average density was 0.01 by $30^{\circ}$ wedge filter, -0.08 $40^{\circ}$ wedge filter and 0.27 non-wedge filter. These average values of difference density were very significant statistically, and standard deviation also was close to regular distribution. In conclusion, there is a usefulness of angled wedge filter for increasing diagnostic value of pancreatic duct tall part on the endoscopic retrograde pancreatogram.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.3
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• pp.231-241
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• 2023

This study was investigated in order to find composition and density of fisheries resource using bottom trawl in April, July, August, and November 2022 in the East China Sea. The average density of fisheries resource was estimated using the swept area method. As a result, 35 species were collected from the East China Sea. These included 21 fishes, six crustaceans, six cephalopods and two echinoderms. Seasonally, the average density of crustacean individuals per unit area were highest in November (692.1 inds./km²), while cephalopod individuals per unit area were highest in August (39.4 inds./km²). The average density of fish individuals per unit area were highest in August at 355.0 (inds./km²).

• Journal of The Association for Neo Medicine
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• v.1 no.1
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• pp.103-113
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• 1996

It is thought that the quantity and quality of the heat stimulation and the mechanism of heating process are important to understand the moxa-combustion. In order to get the basic data on the effective moxa-combustion method, combustion temperature changes (average temperature, peak temperature, average gradient temperature and maximum gradient temperature) of the heating period were measured respectively by the density of moxa material. For the experiment, samples of $300mg/0.26cm^3$ , $400mg/0.26cm^3$ and $500mg/0.26cm^3$ of moxa material were molded in a conical mold with each 10mm in diameter and height. 1. The average temperature and peak temperature of heating period on the moxa-combustion showed higher in the $400mg/0.26cm^3$ and $300mg/0.26cm^3$ than in the $500mg/0.26cm^3$ sample respectively. 2. The average gradient temperature of heating period on the moxa-combustion rose quickly in the $300mg/0.26cm^3$, $400mg/0.26cm^3$ and $500mg/0.26cm^3$ in that order and the maximum gradient temperature rose more quickly in the $300mg/0.26cm^3$ and $400mg/0.26cm^3$ than in the $500mg/0.26cm^3$ sample respectively. According to the above results, it is concluded that the density of moxa material is (the) more important (factor) than the weight or volume of moxa material on the combustion temperature changes of the heating period for the evaluation of the quality and quantity of moxa-combustion.

• Biomedical Science Letters
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• v.7 no.1
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• pp.31-37
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• 2001

The present study was performed to investigate the infection status of heterophyid fluke metacercariae in mullets and gobies collected from some coastal areas of cholla-do. The collected fishes were transferred to the laboratory, artificially digested with pepsin-HCI solution and examined under a stereomicroscope. In 70 mullets examined, the metacercariae of Heterophyes nocens (in 28.6% of fish), Heterophyopsis continua (in 2.9%), Pygidiopsis summa (in 32.9%) and Stictodora spp. (in 14.3%) were detected. The metacercariae of H nocens were detected in mullets from Shinan-gun (in 60.0% of fish), Muan-gun (in 54.4%), Hampyong-gun (in 25.0%) and Yonggwang-gun (in 16.7%). The average metacercarial density per infected fish were 7.6,34, 10 and 5 in each areas. A total of 7 metacercariae of H. continua was detected in only 2 mullets from Hampyong-gun. The metacercariae of p. summa were detected in mullets from Haenam-gun (in 80.0% offish), Muan-gun (in 27.3%), Hampyong-gun (in 16.7%) and Puan-gun (in 100%). The average metacercarial density per infected fish were 350, 14, 5 and 97 in each areas. The metacercariae of Stictodora spp. were detected in mullets from Shinan-gun (in 26.7% offish), Hampyong-gun (in 33.3%) and Puan-gun (in 20.0%). The average metacercarial density per infected fish were 2.8, 18.8 and 2.5 in each areas. In 70 gobies examined, the Metacercariae of H nocens (in 15.7% of fish), H continua (in 47.1%) and Stictodora spp. (in 48.6%) were detected. The metacercariae of H. nocens were detected in gobies from Shinan-gun (in 50.0% of fish) and Yonggwang-gun (in 10.0%). The average metacercarial density per infected fish were 71 and 2 in each areas. The metacercariae of H. continua were detected in gobies from Shinan-gun (in 65.0% of fish), Hampyong-gun (in 70.0%) and Yonggwang-gun (in 60.0%). The average metacercarial density per infected fish were 5.7,6.6 and 3.2 in each areas. The metacercariae of Stictodora spp. were detected in gobies from Shinan-gun (in 80.0% offish), Hampyong-gun (in 70.0%) and Puan-gun (in 40.0%). The average metacercarial density per infected fish were 149,203 and 5.5 in each areas. From the above results, it was confirmed that the mullet and goby from some coastal areas of cholla-do are infected with numerous metacercariae of heterophyid trematodes.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.9
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• pp.1646-1650
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• 2011

SAIDI(System Average Interruption Duration Index) is the index that signifies the power quality of customers. SAIDI is also used to know how well utilities operate their systems. The annual interruption time in the areas that consists of widely distributed customers, is generally longer than that in the areas that consists of heavily concentrated customers. The Reliability index of huge system is not necessarily better or worse than that of small system, because SAIDI is irrelevant to the total amount of power sold or the total number of customers. This paper proposes a customer density very relevant to SAIDI. The proposed customer density is used to modify the existing SAIDI to more clearly express the service level of power supply. A modified WSAIDI(weighted SAIDI) can be a useful indicator helping utilities improve the reliability of their systems and customers evaluate the service level of receiving power.

• 한국전산유체공학회:학술대회논문집
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• 2003.08a
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• pp.219-224
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• 2003

An analysis procedure for the MCFC channel flow has been developed to predict the fuel cell performance. As for the electrochemical reaction, among several chemical reaction models, one that fits the data best is adopted after a comprehensive comparative study. The Wavier-Stokes, energy, and species equations are solved to obtain the velocity, temperature and concentration fields for a specified average current density. The procedure is iterative as the local current density, or the reaction rate, is allowed to vary with the gas composition. A series of calculations are then carried out to examine the effects of gas flow rate, gas composition, gas usage rate, inlet gas temperature, and average current density on the fuel cell performance. The fuel cell characteristics, such as the temperature, current density distributions, and the concentration fields, for various operating conditions are presented and discussed.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.2
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• pp.113-122
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• 2004

This study was conducted to examine the correlation among growth development, bone mineral density, and nutrient intakes in preschool children. A total of 62 preschool children measured the anthropometric characteristics and the bone mineral density of carpus using DEXA. The questionnaires categorized to determine health status, life style, dietary behaviors, and dietary intakes were filled out by children's mothers. The average ages of the study subjects were 62.4 months in boys and 62.1 months in girls. The birth height and weight of the subjects were 50.9 cm and 3.4 kg in boys and 50.3 cm and 3.3 kg in girls, respectively. The average height, weight, % body fat, and obesity index were 111.7 cm, 19.6 kg, 15.0%, -2.1% in boys and 109.4 cm, 18.7 kg, 17.5%, 0.2% in girls, respectively. The bone mineral density in carpus was 0.25 g/cm$^2$ in boys and 0.24 g/cm$^2$. In girls. Proportions of children having regular meals were 69.0%, 94.7%, and 69.0% for breakfast, lunch, and dinner, respectively. The major reasons for irregular meal were poor appetite and lack of time for breakfast and snacks for dinner. Most of the children(52.6%) had breakfast with the whole family together, and all the children had lunch and dinner with a part of the family. Most of the children answered they had snack more than once a day, and 64.3% had an unbalanced diet. The intakes of energy, calcium, iron, zinc, vitamin A, vitamin B$_1$, niacin, and vitamin C did not meet the Korean RDAs. Average bone mineral density in carpus was positively correlated to the body weight, the total body water, the lean body mass, and the obesity index, respectively(p＜0.01, p＜0.01, p＜0.01 and p＜0.01). The body weight, the total body water, and the lean body mass showed the significant negative correlations with the animal iron intake(p＜0.05, p＜0.01 and p＜0.01). The bone mineral density in the distal carpus was negatively correlated to the animal protein intake and the animal iron intake(p＜0.05 and p＜0.05). And the bone mineral density in the ultradis carpus and the average bone mineral density in the carpus were positively correlated to the plant calcium intake(p＜0.05 and p＜0.05). Therefore, more systematic studies to investigate the roles of protein, iron, and calcium in growth development of preschool children were required.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.6
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• pp.457-463
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• 2007

Various correlations of saturated vapor density in a truncated power series form are tested and compared in this study. Saturated vapor density correlation can be expressed relating logarithmic reduced density to the reduced temperature. Five types of correlation has been investigated using saturated vapor density data for 22 pure substance refrigerants from ASHRAE (American Society of Heating, Reftigerating and Air-Conditioning Engineers, Inc.) property tables and NIST (National Institute of Standards and Technology) Chemistry Webbook. Correlations are fitted to the data points by least squares method. Data points are equally weighted. The best type of correlation among the five types is suggested. The results obtained indicate that the best correlations with 3, 4, and 5 terms yield average AAD's (Average Absolute Deviation) of 0.27%, 0.04%, and 0.02%, respectively, while widely used conventional correlations with 3, 4, and 5 terms yield those of 1.19%, 0.61%, and 0.17%. The suggested type of correlation could reduce the number of terms while improving performance.

• International Journal of Highway Engineering
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• v.14 no.6
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• pp.183-190
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• 2012

PURPOSES : The fundamental diagram provides basic information necessary in the analysis of traffic flow and highway operation. When traffic flow is congested, the density-flow points in the fundamental diagram are widely scattered and move in a stochastic manner. This paper investigates the pattern of density-flow point transitions and identifies car-following behaviors underlying the density-flow transitions. METHODS : From a microscopic analysis of 722 fundamental diagrams of NGSIM data, a total of 20 transition patterns of fundamental diagrams are identified. Prominent features of the transition patterns are explained by the behavior of the leader and follower. RESULTS : It is found out that the average speed and the speed difference between the leader and the follower critically determine the density-flow transition pattern. The density-flow path is very sensitive to the values of vehicle speed and spacing especially at low speed and high density such that most fluctuations in the fundamental diagram in the congested regime is due to the noise of speed and spacing variations. CONCLUSIONS : The result of this study suggests that the average speed, the speed difference between the leader and the follower, and the random variations of speed and spacing are dominant factors that explain the transition patterns of a fundamental diagram.