• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.1
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• pp.1-9
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• 2022

The PoN (Proof of Nonce) distributed consensus algorithm basically uses a non-competitive consensus method that can guarantee an equal opportunity for all nodes to participate in the block generation process, and this method was expected to resolve the first trilemma of the blockchain, called the decentralization problem. However, the decentralization performance of the PoN distributed consensus algorithm can be greatly affected by the network transaction transmission delay characteristics of the nodes composing the block chain system. In particular, in the consensus process, differences in network node performance may significantly affect the composition of the congress and committee on a first-come, first-served basis. Therefore, in this paper, we presented a problem by analyzing the decentralization performance of the PoN distributed consensus algorithm, and suggested a fairness control algorithm using a learning-based probabilistic acceptance rule to improve it. In addition, we verified the superiority of the proposed algorithm by conducting a numerical experiment, while considering the block chain systems composed of various heterogeneous characteristic systems with different network transmission delay.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.5
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• pp.19-32
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• 2018

This study focuses on an M/M/1 queue with an attached continuous-type inventory. The customers arrive into the system according to the Poisson process, and are served in their arrival order; i.e., first-come-first-served. The service times are assumed to be independent and identically distributed exponential random variable. At a service completion epoch, the customer consumes a random amount of inventory. The inventory is controlled by the traditional (s, S)-inventory policy with a generally distributed lead time. A customer that arrives during a stock-out period assumed to be lost. For the number of customers and the inventory size, we derive a product-form stationary joint probability distribution and provide some numerical examples. Besides, an operational strategy for the inventory that minimizes the long-term cost will also be discussed.

• Fashion & Textile Research Journal
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• v.14 no.2
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• pp.211-221
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• 2012

The word 'chintz' is thought to be a corruption of spotted cloth. Printing remained a relatively primitive method of decorating textiles in Europe until the second half of the 17th century. The formation of the English East India Company sparked the influx into the West of painted and printed Indian cotton textiles. A William Sherwin took out the first English patent in 1676. The earlist European designs were florals in the Indian manner. Patterns of European flowers returned to England as birds, flowers, trees, vines and stained glass for Victorian chintz. In France, the original and most successsful manufacturer of the distinctive printed fabrics from Jouy was Christophe Philippe Oberkampf. Copperplate printing was introduced to Jouy in 1770, probably reaching the pinnacle of achievement in the craft after 1783 when Jean-Baptiste Huet became chief designer. Huet's style was widely imitated in France and abroad, and the term 'toile de Jouy' has come to be universally applied to monochrome figurative designs wherever and by whomsoever they were produced. Oberkampf served his apprenticeship as an engraver with some leading manufacturers, including a period in Mulhouse. In Alsace, which was not part of France until 1798, the first factory had opened in 1746 in Mulhouse, and the area soon had the largest number of print-works in France.

• Journal of English Language & Literature
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• v.64 no.4
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• pp.617-628
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• 2018

The aim of this essay is to discuss the relationship between Korean literature and Korean intellectual scenes. Since its first introduction to the local context, literature as a genre has served as a field in which colonial and post-colonial intellectuals have attempted to win the accreditation of Western enlightenment. Literature has been regarded as a crucial instrument of liberal arts and education in Korea. Literature has functioned as a social movement in Korea since its inception. During the colonial period, radical intellectuals and literary writers published essays and articles in literary journals. This status as a social movement is still a distinctive characteristic of Korean literature. From the outset, Korean literature has functioned as an enlightenment project for cultural development. As such, Korean literature retains a political meaning of "literariness," which reshuffles the hierarchy of the sensible and creates novelty against given aesthetic regimes. As a result, in the process these regimes are thereby de-purified of their status as purely aesthetic movements; their perspectives thereby come into contact with other discourses and practices outside the art world. This essay argues that as a genre, Korean literature always functions as "world literature" in Korean intellectual scenes.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.2
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• pp.176-189
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• 2024

Vertical takeoff and landing (VTOL) is a core feature of unmanned aerial vehicles (UAVs), which are commonly referred to as drones. In emerging smart logistics, drones are expected to play an increasingly important role as mobile platforms. Therefore, research on last-mile delivery using drones is on the rise. There is a growing trend toward providing drone delivery services, particularly among retailers that handle small and lightweight items. However, there is still a lack of research on a structural definition of the VTOL drone flight model for multi-point delivery service. This paper describes a VTOL drone flight route structure for a multi-drone delivery service using rotary-wing type VTOL drones. First, we briefly explore the factors to be considered when providing drone delivery services. Second, a VTOL drone flight route model is introduced using the idea of the nested graph. Based on the proposed model, we describe various time-related attributes for delivery services using drones and present corresponding calculation methods. Additionally, as an application of the drone route model and the time attributes, we comprehensively describe a simple example of the multi-drone delivery for first-come-first-served (FCFS) services.

• Journal of KIISE:Information Networking
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• v.30 no.2
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• pp.244-251
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• 2003

As the Internet and wireless mobile communication is being widespread, the WAP (Wireless Application Protocol) that merges these two technologies has emerged. Also, the research of the WAP gateway that enables efficient processing of multiple user demands concurrently and prompt response to requests from various wireless devices has been performed in many working groups. The WAP stack is the most fundamental technology among these researches. In this paper, we implement the WAP container utilizing the JAVA's multithreading and applying to the connection pooling technique to manage the available resource in the container efficiently. Also, we design and implement the WTP(Wireless Transaction Protocol) layer and the UDP(User Datagram Protocol) layer based on the priority Policy. Our design and implementation showed the shorter waiting time than that of the existing FCFS(First-Come, First-Served) system in the transaction layer and its efficiency was proved through simulation.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.1
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• pp.89-99
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• 2020

In this paper, we consider a dyadic server control policy that combines workload control and single vacation. Customer arrives at the system with Bernoulli process, waits until his or her turn, and then receives service on FCFS(First come first served) discipline. If there is no customer to serve in the system, the idle single server spends a vacation of discrete random variable V. If the total service times of the waiting customers at the end of vacation exceeds predetermined workload threshold D, the server starts service immediately, and if the total workload of the system at the end of the vacation is less than or equal to D, the server stands by until the workload exceeds threshold and becomes busy. For the discrete-time Geo/G/1 queueing system operated under this dyadic server control policy, an idle period is analyzed and the steady-state queue length distribution is derived in a form of generating function.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.2
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• pp.63-81
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• 2008

WiMAX has been introduced as a competitive alternative for metropolitan broadband wireless access technologies. It is connection oriented and it can provide very high data rates, large service coverage, and flexible quality of services (QoS). Due to the large number of connections and flexible QoS supported by WiMAX, the uplink access in WiMAX networks is very challenging since the medium access control (MAC) protocol must efficiently manage the bandwidth and related channel allocations. In this paper, we propose and investigate a cost-effective WiMAX bandwidth management scheme, named the WiMAX partial sharing scheme (WPSS), in order to provide good QoS while achieving better bandwidth utilization and network throughput. The proposed bandwidth management scheme is compared with a simple but inefficient scheme, named the WiMAX complete sharing scheme (WCPS). A maximum entropy (ME) based analytical model (MEAM) is proposed for the performance evaluation of the two bandwidth management schemes. The reason for using MEAM for the performance evaluation is that MEAM can efficiently model a large-scale system in which the number of stations or connections is generally very high, while the traditional simulation and analytical (e.g., Markov models) approaches cannot perform well due to the high computation complexity. We model the bandwidth management scheme as a queuing network model (QNM) that consists of interacting multiclass queues for different service classes. Closed form expressions for the state and blocking probability distributions are derived for those schemes. Simulation results verify the MEAM numerical results and show that WPSS can significantly improve the network’s performance compared to WCPS.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.9-16
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• 2003

In this paper, we propose a method for supporting VCR operations in a patching based multicast VOD system. Random access, pause and resume operations are supported in our system, and the channel and session scheduling algorithms for the VCR operations are proposed. When it is necessary to join a sharable multicast channel in the admission control for the VCR operations, the patching technique, which shares an on-going regular channel and allocates a new patching channel for the missing data, is used. Therefore, unlike the previous approach that allocates an excessive number of I-channels, service latency is minimized and channel usage is optimized in our system. Moreover buffered data. which is saved in disk during patching, is reused to prevent unnecessary patching channel allocation. For this. the patching management information is extended and a buffed data management scheme is proposed. In our system, the First-Come-First-Served scheduling is used to inform clients the service latency for the VCR operations immediately.

• Journal of the Korea Society of Computer and Information
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• v.18 no.11
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• pp.221-227
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• 2013

Cybersquatting is a type of conflicts between a trademark and a domain, and refers to "behaviors of registering, retaining, transferring, and using the identical or similar domain name in bad faith for the profit from the mark such as trademark". That is, it is preoccupying behavior to abuse the fact that the domain name in the Internet can be freely registered on a first come, first served basis and can't duplicate. Though this should be prohibited, given the reality that most of our daily lives are based in the Internet, this is creating many problems in IT environment beyond social structure in rule of law. Therefore, this study has the purpose that it provides cybersquatting-related information and suggests legislative implications hereafter through the analysis of cybersquatting-related precedent from the Supreme Court.