• Title/Summary/Keyword: 순열

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Differential Spatial Modulation with Gray Coded Antenna (그레이 코드화된 안테나 순서의 차등 공간 변조)

  • Kim, Jeong-Su;Lee, Moon Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.5
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    • pp.51-59
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    • 2017
  • In this paper, we propose a gray code order of antenna index permutations for differential spatial modulation (DSM). To facilitate the implementation, the well-known Trotter-Johnson ranking and unranking algorithms are adopted, which result in similar computational complexity to the existing DSM that uses the lexicographic order. The signal-to-noise ratio gain achieved by the proposed gray code order over the lexicographic order is also analyzed and verified via simulations. Based on the gray coding framework, we further propose a diversity-enhancing scheme named intersected gray (I-gray) code order, where the permutations of active antenna indices are selected directly from the odd (or even) positions of the full permutations in the gray code order. From analysis and simulations, it is shown that the I-gray code order can harvest an additional transmit diversity order with respect to the gray code order.

The Study of Factors of Anxiety of Permutation and Combination in High School (고등학교 순열과 조합 단원의 불안요인 연구)

  • Kim, Mi-Jeong;Kim, Yong-Gu;Jung, In-Chul
    • Journal of the Korean School Mathematics Society
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    • v.12 no.2
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    • pp.261-279
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    • 2009
  • Permutation and combination are the subjects that most teachers feel difficult to teach in Mathematics. This paper investigated evaluation items and factors of anxiety of students for permutation and combination, and further examined the way to lessen the factors of anxiety. Two high school students participated for over a year from December 2007 to February 2008. Also, two teachers joined for the analysis of evaluation items. We found that the ill-structured problems and word problems are the main factors to bring about the anxiety, whereas cooperative learning with high intelligent peers, practice to read word problems and write the process of problems solving are helpful in lessening the mathematical anxieties. Further we propose that the study of appropriate teaching and learning method for permutation and combination should be performed in the future.

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Non-parametric approach for the grouped dissimilarities using the multidimensional scaling and analysis of distance (다차원척도법과 거리분석을 활용한 그룹화된 비유사성에 대한 비모수적 접근법)

  • Nam, Seungchan;Choi, Yong-Seok
    • The Korean Journal of Applied Statistics
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    • v.30 no.4
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    • pp.567-578
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    • 2017
  • Grouped multivariate data can be tested for differences between two or more groups using multivariate analysis of variance (MANOVA). However, this method cannot be used if several assumptions of MANOVA are violated. In this case, multidimensional scaling (MDS) and analysis of distance (AOD) can be applied to grouped dissimilarities based on the various distances. A permutation test is a non-parametric method that can also be used to test differences between groups. MDS is used to calculate the coordinates of observations from dissimilarities and AOD is useful for finding group structure using the coordinates. In particular, AOD is mathematically associated with MANOVA if using the Euclidean distance when computing dissimilarities. In this paper, we study the between and within group structure by applying MDS and AOD to the grouped dissimilarities. In addition, we propose a new test statistic using the group structure for the permutation test. Finally, we investigate the relationship between AOD and MANOVA from dissimilarities based on the Euclidean distance.

A High Speed Optimized Implementation of Lightweight Cryptography TinyJAMBU on Internet of Things Processor 8-Bit AVR (사물 인터넷 프로세서 8-bit AVR 상에서의 경량암호 TinyJAMBU 고속 최적 구현)

  • Hyeok-Dong Kwon;Si-Woo Eum;Min-Joo Sim;Yu-Jin Yang;Hwa-Jeong Seo
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.2
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    • pp.183-191
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    • 2023
  • Cryptographic algorithms require extensive computational resources and rely on complex mathematical principles for security. However, IoT devices have limited resources, leading to insufficient computing power. As a result, lightweight cryptography has emerged, which uses fewer computational resources. NIST organized a competition to standardize lightweight cryptography and TinyJAMBU, one of the algorithms in the competition, is a permutation-based algorithm that repeats many permutation operations. In this paper, we implement TinyJAMBU on an 8-bit AVR processor with a proposedtechnique that includes a reverse shift method and precomputing some operations in a fixed key and nonce environment. Our techniques showed a maximum performance improvement of 7.03 times in permutation operations and 5.87 times in the TinyJAMBU algorithm, improving up to 9.19 times in a fixed key and nonce environment.

Effect of Young Barley Leaf on Lipid Contents and Hepatic Lipid-Regulating Enzyme Activities in Mice Fed High-Fat Diet (보리순이 고지방을 급여한 마우스의 지질 함량과 간조직의 지질대사 관련 효소활성에 미치는 영향)

  • Yang, Eun-Ju;Cho, Young-Sook;Choi, Myung-Sook;Woo, Myoung-Nam;Kim, Myung-Joo;Shon, Mi-Yae;Lee, Mi-Kyung
    • Journal of Nutrition and Health
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    • v.42 no.1
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    • pp.14-22
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    • 2009
  • This study was conducted to investigate the effects of powdered young barley leaf and its water extract on body weight and lipid metabolism in high-fat fed mice. Male mice were divided into normal group, high-fat (HF) group, high-fat group supplemented with powdered young barley leaf (HF-YBL) and high-fat group supplemented with water extract of the powdered young barley leaf (HF-WYBL). The powdered young barley leaf or its water extract was added to a standard diet based on 1% dried young barley leaf (1 g YBL/100 diet and 0.28 g WYBL/100 g diet) for 8 weeks. Supplementation of YBL and WYBL significantly reduced body weight and epididymal adipose tissue weight in high-fat fed mice. Food intake and daily energy intake were significantly lower in the YBL group than in the HF group. After 8 weeks, plasma triglyceride and cholesterol concentrations were significantly higher in the HF group than in the Normal group; however, both YBL and WYBL significantly lowered those of the high-fat fed mice. The ratio of HDL-cholesterol/total cholesterol of the YBL and WYBL groups were significantly elevated compared to that of HF group. Both YBL and WYBL significantly increased fecal excretion of triglyceride in high-fat fed mice, whereas they did not affect fecal cholesterol concentration. The triglyceride levels of liver, adipose tissue and heart were significantly lower in the YBL and WYBL groups than in the HF group. Supplementation of WYBL also lowered the kidney triglyceride and heart cholesterol concentrations compared to those of HF group. Hepatic lipid regulating enzyme activities, fatty acid synthase, HMG-CoA reductase and acyl-coenzyme A: cholesterol acyltransferase, were significantly lower in the YBL and WYBL groups than in the HF group. Accordingly, these results suggest that YBL and WYBL improve plasma and organ lipid levels partly by increasing fecal lipid excretion and inhibiting fatty acid and cholesterol biosynthesis in the liver.

A COMPARATIVE STUDY ON CRONIN TRIANGULAR FLAP AND ROTATION-ADVANCEMENT REPAIR IN UNILATERAL COMPLETE CLEFT LIP (편측성 완전구순열에서 Cronin 삼각피판법과 회전신전법에 의한 수복의 비교)

  • Ryu, Sun-Youl;Yun, Cheon-Ju
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.23 no.5
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    • pp.415-421
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    • 2001
  • The present study was carried out to compare the postoperative results of Cronin triangular flap and Millard rotation-advancement repair techniques in repairing the unilateral complete cleft lip. Thirteen patients with unilateral complete cleft lip underwent 6 Cronin triangular flap and 7 Millard rotation-advancement repairs at the Department of Oral and Maxillofacial Surgery of Chonnam University Hospital over a period of 6 years (January 1994 to December 1999). The surgical results following the operation were assessed on the basis of scoring, vertical lip length and scar hypertrophy. The mean score was better in Cronin triangular flap group($74.77{\pm}0.86$) than in Millard rotation-advancement group($66.50{\pm}1.14$) for both lip and nose segments. Scar hypertrophy developed in the Millard rotation-advancement repair group with 28.6% incidence but not in the Cronin triangular flap group. No significant difference was found in the ratio of lip length between Millard rotation-advancement repair and Cronin triangular flap groups($0.73{\pm}0.10$ and $0.80{\pm}0.96$). These results suggest that Cronin triangular flap shows better results than Millard rotation-advancement repair in repairing the unilateral complete cleft lip.

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Eye Movements in Understanding Combinatorial Problems (순열 조합 이해 과제에서의 안구 운동 추적 연구)

  • Choi, In Yong;Cho, Han Hyuk
    • Journal of Educational Research in Mathematics
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    • v.26 no.4
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    • pp.635-662
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    • 2016
  • Combinatorics, the basis of probabilistic thinking, is an important area of mathematics and closely linked with other subjects such as informatics and STEAM areas. But combinatorics is one of the most difficult units in school mathematics for leaning and teaching. This study, using the designed combinatorial models and executable expression, aims to analyzes the eye movement of graduate students when they translate the written combinatorial problems to the corresponding executable expression, and examines not only the understanding process of the written combinatorial sentences but also the degree of difficulties depending on the combinatorial semantic structures. The result of the study shows that there are two types of solving process the participants take when they solve the problems : one is to choose the right executable expression by comparing the sentence and the executable expression frequently. The other approach is to find the corresponding executable expression after they derive the suitable mental model by translating the combinatorial sentence. We found the cognitive processing patterns of the participants how they pay attention to words and numbers related to the essential informations hidden in the sentence. Also we found that the student's eyes rest upon the essential combinatorial sentences and executable expressions longer and they perform the complicated cognitive handling process such as comparing the written sentence with executable expressions when they try the problems whose meaning structure is rarely used in the school mathematics. The data of eye movement provide meaningful information for analyzing the cognitive process related to the solving process of the participants.