• Journal of the Korean Dietetic Association
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• v.25 no.1
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• pp.44-58
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• 2019

Predicting the number of meals in a foodservice organization is an important decision-making process that is essential for successful food production, such as reducing the amount of residue, preventing menu quality deterioration, and preventing rising costs. Compared to other demand forecasts, the menu of dietary personnel includes diverse menus, and various dietary supplements include a range of side dishes. In addition to the menus, diverse subjects for prediction are very difficult problems. Therefore, the purpose of this study was to establish a method for predicting the number of meals including predictive modeling and considering various factors in addition to menus which are actually used in the field. For this purpose, 63 variables in eight categories such as the daily available number of people for the meals, the number of people in the time series, daily menu details, weekdays or seasons, days before or after holidays, weather and temperature, holidays or year-end, and events were identified as decision variables. An ensemble model using six prediction models was then constructed to predict the number of meals. As a result, the prediction error rate was reduced from 10%~11% to approximately 6~7%, which was expected to reduce the residual amount by approximately 40%.

• Transactions of Materials Processing
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• v.28 no.2
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• pp.63-70
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• 2019

This study investigates the effects of multi-axial diagonal forging (MADF) processing number on the microstructures of AA1100 fabricated using MADF processes. The cast AA1100 was annealed at $400^{\circ}C$ for 3hrs in $N_2$ atmosphere and cut into $25mm^3$ cubes for the MADF processes. The MADF process consist of plane forging with a thickness reduction of 30% and a diagonal forging with a diagonal forging angle of 135 degrees. In order to analyze the microstructural variations based on the number of repetitions, 1, 2, 3 and 4 cycles of the MADF process were performed. AA1100 specimens were successfully deformed without cracking of the surface for up to 4 cycles of MADF. The grain size, average misorientation and average grain orientation spread (GOS) of MADF processed materials were analyzed using EBSD technique. The results showed that MADF process effectively refined the microstructure of AA1100 with an initial average grain size of $337.4{\mu}m$. The average grain sizes of specimens which were MADF processed for 2, 3, 4 cycles were refined to be $1.9{\mu}m$, $1.6{\mu}m$, $1.4{\mu}m$, respectively. The grain refinement appeared saturated when AA1100 got MADF processed over 2 cycles. When the specimen was subjected to two or more cycles of MADF, the degree of decrease in the average grain size drastically decreased with an increase in the number of cycle due to the softening phenomena such as dynamic recovery or dynamic recrystallization during processing.

• Proceedings of the Korean Society of Computational and Applied Mathematics Conference
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• 2003.09a
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• pp.16.1-16
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• 2003

A subset S of vertices of a graph G is independent if no two vertices of S are adjacent by an edge in G. Also we say that S is maximal independent if it is contained In no larger independent set in G. A planted plane tree is a tree that is embedded in the plane and rooted at an end-vertex. A (k＋1) -valent tree is a planted plane tree in which each vertex has degree one or (k＋1). We classify maximal independent sets of (k＋1) -valent trees into two groups, namely, type A and type B maximal independent sets and consider specific independent sets of these trees. We study relations among these three types of independent sets. Using the relations, we count the number of all maximal independent sets of (k＋1) -valent trees with n vertices of degree (k＋1).

• Journal of Integrative Natural Science
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• v.13 no.1
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• pp.19-26
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• 2020

In this paper, we study on the reinterpretation of Burnside's theorem that is a tool to compute the number of equivalence classes of a group action on a set, and by applying it, we find out the numbers of different patterns in coloring problems of various types of figures with symmetry and use them for computing the numbers of different kinds of chemical compounds.

• Bulletin of the Korean Mathematical Society
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• v.56 no.4
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• pp.815-827
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• 2019

It is well known that the denominator of the Dedekind sum s(c, d) divides 2 gcd(d, 3)d and that no smaller denominator independent of c can be expected. In contrast, here we prove that we usually get a smaller denominator in S(H, d), the sum of the s(c, d)'s over all the c's in a subgroup H of order n > 1 in the multiplicative group $(\mathbb{Z}/d\mathbb{Z})^*$. First, we prove that for p > 3 a prime, the sum 2S(H, p) is a rational integer of the same parity as (p-1)/2. We give an application of this result to upper bounds on relative class numbers of imaginary abelian number fields of prime conductor. Finally, we give a general result on the denominator of S(H, d) for non necessarily prime d's. We show that its denominator is a divisor of some explicit divisor of 2d gcd(d, 3).

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.311-324
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• 1992

The purpose of this study is to take precautions against smoking behavior and delinquent by investigating the relation between smoking behavior and delinquent, analysing variables influence smoking behavior and delinquent. For the data set 1522 boys' high school students living in Pusan were chosen. The data were analyzed with the SPSS PC+ statistical package using Pearson's correlation and multiple regression. The main results are as follows: First, the rate of smoking is 39.4% among 1522 boys' high school students. First grade is 22.0%. Second grade is 44.5%. Third grade is 53.4%. Second, Delinquent experiences are in the order of going to game room(92.7%), drinking(89.4%), going to the prohibited movies(74.2%), thief(39.8%), going to discotheque(32.8%), kiss(29.8%). Third, smoking behavior and delinquent have positive correlationship. Forth, among the independent variables, grade, scholastic attainments, pocket-money, relegion, intimate friend's smoking, number of smoking friend, number of smoking family, family's thought on smoking have influence on smoking behavior. Fifth, among the sociopopulational variables, pocket money, scholastic attainments, club have influence on delinquent experience. Among enviornmental variables, intimate friend's smoking, number of smoking friend, girl friend, girl friend's smoking have influence on delinquent experience. Number of smoking family, parents' smoking, sibling's smoking, family's thought on smoking have partially influence on delinquent experience.

• Journal of Pharmacopuncture
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• v.24 no.3
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• pp.122-137
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• 2021

Objectives: In South Korea, traffic accident victims can be treated under automobile insurance coverage. Korean medicine (KM) clinics have reported the largest number of automobile insurance fee claims among medical institutions. This study investigated the status of the KM automobile insurance system in a single KM clinic. Methods: We retrospectively surveyed the medical charts of 342 traffic accident patients treated at the Jisung KM clinic between January 2009 and June 2017. Results: Most of the patients were men and in their 30s. The most common method of locating the clinic was an internet search. The most common traffic accident type was collision between vehicles (83.63%), with 70.76% of patients visiting during the most acute phase. The major disease codes included S434, M4836, F072, S0600, and S3350. The most frequent treatment period was within 1 month of the accident, and most patients received 10 or fewer treatments. The mean treatment duration and number of treatments were 37.68 ± 45.11 days and 11.68 ± 10.63 treatments, respectively. The initial pain numerical rating scale (NRS), 7.32 ± 0.96, decreased to 3.57 ± 1.40 at the end of treatment, with a symptom improvement score of 1.87 ± 0.60. Regarding sex, age, disease duration, location at the time of the accident, presence of additional and psychological symptoms, and chuna, there were statistically significant differences in treatment duration and number of treatments. A higher number of treatments and the longer treatment duration was associated with a higher initial NRS, lower post-treatment NRS, and better improvement score. Since the introduction of traffic accident (TA) pharmacopuncture, the rate of use of a single type of pharmacopuncture increased; however, no significant differences in treatment duration and number, NRS before and after treatment, and improvement score were observed between treatment groups before and after TA pharmacopuncture. No adverse reactions were observed for any treatment. Conclusion: This study confirmed the previous findings of a high treatment effect of KM under automobile insurance. We also observed significant correlations based on a detailed medical status, which may explain the increasing use of KM in the automobile insurance system. Additional multi-center studies in different regions are needed.

• International Journal of High-Rise Buildings
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• v.10 no.1
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• pp.73-83
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• 2021

The door open time, resulting from occupants evacuating from apartments, is an important parameter when assessing the performance of smoke ventilation systems in high-rise apartment buildings. However, the values recommended in UK design guidance appear to have limited substantiation. Monte Carlo simulations have been carried out considering variabilities in door swing time, flow rate and number of occupants. It has been found that the door open time can be represented by a lognormal distribution with a mean of 6.6, 8.7 and 11.1 s and a standard deviation of 1.7, 3.2 and 4.7 s for one, two and three-bedroom apartments, respectively. For deterministic analyses, it is proposed that the 95th percentile values may be adopted in line with recommended practice for other fire safety design parameters such as fuel load density and soot yield, giving door open times of 10 s to 19 s, depending on the number of bedrooms.

• Communications for Statistical Applications and Methods
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• v.31 no.1
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• pp.1-35
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• 2024

The assumption of homoscedasticity is one of the most crucial assumptions for many parametric tests used in the biological sciences. The aim of this paper is to compare the empirical probability of type I error and the power of ten parametric and two non-parametric tests for homoscedasticity with simulations under different types of distributions, number of groups, number of samples per group, variance ratio and significance levels, as well as through empirical data from an agricultural experiment. According to the findings of the simulation study, when there is no violation of the assumption of normality and the groups have equal variances and equal number of samples, the Bhandary-Dai, Cochran's C, Hartley's Fmax, Levene (trimmed mean) and Bartlett tests are considered robust. The Levene (absolute and square deviations) tests show a high probability of type I error in a small number of samples, which increases as the number of groups rises. When data groups display a nonnormal distribution, researchers should utilize the Levene (trimmed mean), O'Brien and Brown-Forsythe tests. On the other hand, if the assumption of normality is not violated but diagnostic plots indicate unequal variances between groups, researchers are advised to use the Bartlett, Z-variance, Bhandary-Dai and Levene (trimmed mean) tests. Assessing the tests being considered, the test that stands out as the most well-rounded choice is the Levene's test (trimmed mean), which provides satisfactory type I error control and relatively high power. According to the findings of the study and for the scenarios considered, the two non-parametric tests are not recommended. In conclusion, it is suggested to initially check for normality and consider the number of samples per group before choosing the most appropriate test for homoscedasticity.

• Journal of applied mathematics & informatics
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• v.41 no.6
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• pp.1193-1207
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• 2023

In this paper, we introduce an iP₂ extension of a star graph S_n for n ≥ 2 and 1 ≤ i ≤ n - 1. Certain general properties satisfied by order, size, domination (or Roman) numbers γ (or γ_R) of an iP₂ extended star graph are studied. Finally, we study how the parameters such as chromatic number and harmonious chromatic number are affected when an iP₂ extension process acts on the star graphs.