• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.377-380
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• 2008

Ground state structures and ring flipping transition states of eight- and seven-membered silicon containing heterocyclic compounds such as dithienodisilacyclooctatriene and oxadithienodisilacycloheptadiene derivatives, respectively have theoretically been investigated. Although the bithienylene moiety of the derivatives does not change the ground state structures, they significantly increase the ring flipping barrier by 13-17 kcal/mol in the case of the eight-membered rings (2, 3, and 4) in comparison with that of silicon containing heterocyclic compound 6, chosen as a model. The same moiety increases the flipping barrier of seven-membered ring (5) is only slightly (3.3 kcal/mol) in comparison with that of model compound 7. Hence, it has been concluded that not only the existing ring strain of eight-membered ring but also the bithienylene moiety collectively increases the ring flipping barrier so as to prevent such conformational changes explaining anomalous NMR behaviour of dithienodisilacyclooctatriene derivatives (2-4). In contrast, the effect of substituents R1 and R2 at the olefinic carbons of the eight-membered ring on the flipping barrier turned out to be mild.

• 전자공학회논문지 IE
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• v.43 no.4
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• pp.115-121
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• 2006

In this paper, we proposed about data error check and correction on channel transmission in the communication system. LDPC codes are used for minimizing channel errors by modeling AWGN Channel as a VDSL system. Because LDPC Codes use low density parity bit, mathematical complexity is low and relating processing time becomes shorten. Also the performance of LDPC code is better than that of turbo code in long code word on iterative decoding algorithm. This algorithm is better than conventional algorithms to correct errors, the proposed algorithm assigns weights for errors concerning parity bits. The proposed weighted Bit-flipping algorithm is better than the conventional Bit-flipping algorithm and we are recognized improve gain rate of 1 dB.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.4
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• pp.1296-1309
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• 2023

In this paper, based on the soft cancellation (SCAN) bit-flipping (SCAN-BF) algorithm, a generalized SCAN bit-flipping (GSCAN-BF-Ω) decoding algorithm is carried out, where Ω represents the number of bits flipped or corrected at the same time. GSCAN-BF-Ω algorithm corrects the prior information of the code bits and flips the prior information of the unreliable information bits simultaneously to improve the block error rate (BLER) performance. Then, a joint threshold scheme for the GSCAN-BF-2 decoding algorithm is proposed to reduce the average decoding complexity by considering both the bit channel quality and the reliability of the coded bits. Simulation results show that the GSCAN-BF-Ω decoding algorithm reduces the average decoding latency while getting performance gains compared to the common multiple SCAN bit-flipping decoding algorithm. And the GSCAN-BF-2 decoding algorithm with the joint threshold reduces the average decoding latency further by approximately 50% with only a slight performance loss compared to the GSCAN-BF-2 decoding algorithm.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.237-246
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• 2021

This paper explores the relationship between price mechanism and flipping activity of initial public offerings (IPOs) in Pakistan's emerging economy. This study uses a cross-sectional data set of 95 firms listed on Pakistan Stock Exchange from 2000 to 2019. This study employs the ordinary least square and quantile regression techniques to capture the relationship between price mechanism and flipping activity. The results show that book-built IPOs flip substantially less than fixed-price IPOs. This is consistent with the signaling theory assertion that roadshows are arranged by underwriters to capture investors' demand and set the offer prices of IPOs. If investors learn the fair values of quality IPOs, then the offer prices will be close to the intrinsic values, thus reducing flipping. The findings also provide conclusive evidence for understanding the usefulness of and the more relevant information regarding the pricing mechanism. In particular, it provides a better understanding of how companies actually use the pricing mechanism information in the flipping of IPO shares. The results of this study are also valuable to underwriters, and regulators, for instance, provides underwriters with the discretion to allocate the IPO shares and the SECP, in revising regulation on the disclosure of IPO pricing methods.

• The Journal of Korea Robotics Society
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• v.14 no.2
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• pp.81-86
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• 2019

Robots are used in various industrial sites, but traditional methods of operating a robot are limited at some kind of tasks. In order for a robot to accomplish a task, it is needed to find and solve accurate formula between a robot and environment and that is complicated work. Accordingly, reinforcement learning of robots is actively studied to overcome this difficulties. This study describes the process and results of learning and solving which applied reinforcement learning. The mission that the robot is going to learn is bottle flipping. Bottle flipping is an activity that involves throwing a plastic bottle in an attempt to land it upright on its bottom. Complexity of movement of liquid in the bottle when it thrown in the air, makes this task difficult to solve in traditional ways. Reinforcement learning process makes it easier. After 3-DOF robotic arm being instructed how to throwing the bottle, the robot find the better motion that make successful with the task. Two reward functions are designed and compared the result of learning. Finite difference method is used to obtain policy gradient. This paper focuses on the process of designing an efficient reward function to improve bottle flipping motion.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.4
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• pp.35-53
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• 2016

Many publishers tried flipping, or extensively changed their journals flipped. They considered that converting an established journal into OA journal is more attractive than launching an entirely new OA journal. After conducting a careful literature review, this study provided the background and current situations on flipping. There are flipped OA journals alive published by commercial publisher, society, university, and institute in the field of science and medicine. This study found the increased number of published articles after flipping, with 69% of 97 flipped OA journals in 2015 having impact factors. Also 92% of the journals experienced rising in ranking of impart factor, or achieved it for the first time. It was suggested that the roles of academic society, funding agencies, and universities when it comes to active flipping.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5C
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• pp.498-504
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• 2009

A high-performance low-complexity decoding algorithm for LDPC codes is proposed in this paper, which has the advantages of both bit-flipping (BF) algorithm and sum-product algorithm (SPA). The proposed soft bit-flipping algorithm requires only simple comparison and addition operations for computing the messages between bit and check nodes, and the amount of those operations is also small. By increasing the utilization ratio of the computed messages and by adopting nonuniform quantization, the signal-to-noise ratio (SNR) gap to the SPA is reduced to 0.4dB at the frame error rate of 10-4 with only 5-bit assignment for quantization. LDPC codes with high column or row weights, which are not suitable for the SPA decoding due to the complexity, can be practically implemented without much worsening the error performance.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.535-537
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• 2005

디지털 신호 및 전송부호의 오류검출에는 예전부터 패리티 체크가 사용되어 왔다. 그러나 패리티 체크 기법은 구현 및 알고리즘이 단순, 간결한 우수성이 있지만 특정 데이터 비트의 경우 오류 검출이 불가능하다는 문제점을 가지고 있다. 이후 패리티 체크 기법은 해밍 코드 및 채널 오류 정정을 위한 LDPC 코드와 같은 다양한 오류검출 및 정정 알고리즘에 적용되어 발전되어 왔으며, 그 중 LDPC 코드의 bit-flipping 알고리즘에서는 패리티 기법을 반복적으로 적용하는 방식을 택하고 있다. 본 논문에서는 이러한 채널 오류 정정을 위한 LDPC의 bit-flipping 알고리즘을 이차원 코드에 적용하고, 이 때 bit-flipping 알고리즘이 가지고 있는 문제점을 보완할 수 있는 개선된 LDPC 코드를 제안한다.

• ETRI Journal
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• v.36 no.1
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• pp.171-174
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• 2014

In weighted bit-flipping-based algorithms for low-density parity-check (LDPC) codes, due to the existence of overconfident incorrectly received bits, the metric values of the corresponding bits will always be wrong in the decoding process. Since these bits cannot be flipped, decoding failure results. To solve this problem, an improved parallel weighted bit flipping algorithm is proposed. Specifically, a reliability-saturation strategy is adopted to increase the flipping probability of the overconfident incorrectly received bits. Simulation results show that the error floor of LDPC codes is greatly lowered.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.456-459
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• 2006

Effects of pork thickness (5 and 7 mm), heating temperature (190 and $220^{\circ}C$) and time (40-180 sec), and flipping interval (10 and 30 sec) during cooking against survival levels of general bacteria and pathogenic microorganisms in pork were investigated. Under same heating temperature and time, 10 sec interval of flipping was more effective in sterilizing bacteria than 30 sec interval. Bacteria was not detected in 5-mm thick pork cooked for 80 sec at $190^{\circ}C$ with 10 sec flipping interval, and 120 sec heating at $190^{\circ}C$ and 30 sec flipping interval. Bacteria were not detected in most 7-mm thick pork cooked for 100 sec at $190^{\circ}C$ with 10 sec flipping interval, and 180 sec heating at $190^{\circ}C$ and 30 sec interval. Bacteria were not detected in most 5- and 7-mm thick pork cooked for 80 sec at $220^{\circ}C$ with 10 sec flipping interval, and 120 sec heating with 30 sec interval.