• Journal of Communications and Networks
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• v.13 no.5
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• pp.511-517
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• 2011

The capacity of wireless ad-hoc networks is analyzed for all kinds of information dissemination based on single and multiple packet reception schemes under the physical model. To represent the general information dissemination scheme, we use (n, m, k)-cast model [1] where n, m, and k (k ${\leq}$ m) are the number of nodes, destinations and closest destinations that actually receive packets from the source in each (n, m, k)-cast group, respectively. We first consider point-to-point communication, which implies single packet reception between transmitter-receiver pairs and compute the (n, m, k)-cast communications. Next, the achievable throughput capacity is computed when receiver nodes are endowed with multipacket reception (MPR) capability. We adopt maximum likelihood decoding (MLD) and successive interference cancellation as optimal and suboptimal decoding schemes for MPR. We also demonstrate that physical and protocol models for MPR render the same capacity when we utilize MLD for decoding.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.1
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• pp.11-23
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• 2018

This paper investigated relationship among internal as well as external motive to receive the ISO 13485 certification, countermeasure to the certification examination, active reception/execution level of the certification, and operational as well as financial performance of the medical device related enterprises in South Korea which received and are maintaining the ISO 13485 certification. SEM (structural equation model) and related analyses using AMOS 21.0 and SPSS 21.0 have been applied to verify the hypotheses of the research. Result of the research showed that internal as well as external motive for certification positively(+) affects active reception/execution level of the certification as well as countermeasure to the certification examination. The reception/execution level of the certification also positively(+) affects on the operational as well as financial performance of the certified enterprises. However, countermeasure to the certification examination was found out to negatively(-) affects the active reception/execution level of the certification and we can interpret that relatively more countermeasure to the certification examination burdens the employees of the enterprise, causing them to be less active on the reception/execution level of the certification. This research found that an enterprise's operational/financial performance improves when an enterprise introduces the ISO 13485 certification standard spontaneously on the purpose of improving its system and the certification system is applied to the enterprise actively, not passively. This research emphasizes the need to recognize the difference of the level of active reception implication among members of an enterprise according to the motive of introduction of the certification system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.9
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• pp.811-820
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• 2012

GNSS signal is vulnerable to jamming signal because of well-known signal structure and weak signal power. For these reasons, the need for analysis of jamming effects and anti-jamming techniques of is increasing. In this paper, a GNSS signal generator is designed which includes a radio wave propagation model for six kind of tactical environments and a body masking model for the reception environment of a vehicle. The radio wave propagation model for downtown, rural, forest, coastline, waste land and snow or ice area is designed using two-ray model. The body masking model is designed the effect which the antenna is affected by the reception environment of a vehicle and radiation pattern from a user configuration. The performance of generated signals from the GNSS signal generator considering reception environment of a vehicle is evaluated by a commercial GPS L1 receiver(NordNav) in normal and jamming environment. Also, the generated GNSS signal is compared to a commercial GPS L1 H/W based RF signal generator(STR4500). The results show that the designed GNSS signal generator in a normal environment compared to the same navigation performance. In jamming environment, it is shown that the body masking effect and GNSS signal acquisition and tracking loss in compliance with the jamming signal are precisely working in the reception environment of a vehicle.

• Journal of Ship and Ocean Technology
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• v.8 no.3
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• pp.18-25
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• 2004

Sound reception system is required to detect the sound and the quadrantal direction of the other ship's horn sound, to overcome the effects of enclosed wall for navigation space, functioning as a sound barrier. However, the realized systems can only provide quadrantal information of the other ship. This paper presents a new arrangement of microphones, having geometrically symmetric deployment with the same distances between sensors and the same angles between adjacent sensors with respect to the geometrical center. The sound pressures received at microphones are transformed into the related envelope signals by applying Hilbert transform. The time delays between microphones are estimated by the correlation functions between the derived envelope signals. This envelope base processing mitigates the noises related to the reflection by ship and sea surface. Then, the directional information is easily defined by using the estimated time delays. The suggested method is verified by the generated signals using boundary element method for a small ship model with sea surface wave. The estimated direction is quite similar to the true one and therefore the proposed approach can be used as an efficient sound reception system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.475-484
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• 2020

This monograph was probed effectively by using practical methods in a subjectivity study that was accessible in depth, departing from bygone behavior of functional quantity analysis of awareness and the opinions of young people about the general (public) model of TV advertising. The perception patterns resolved in this study sorted out four types in a Q-methodology. The result is divided as follows: 1 [(N=7): Advertising Consensus Type], 2 [(N=7): Advertising Negative Type], 3 [(N=5): Advertising Purchasing Reduction Type], and 4 [(N=1): Advertising Persuasion Orientation Type]. As such, we found very different types all over. Finally, this study reviews subjective acceptance as to the type of model reception with regard to general TV advertising, offering a developmental suggestion on the issue, and an agenda about it.

• Journal of The Korean Association For Science Education
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• v.33 no.2
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• pp.522-537
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• 2013

This study analyzed the relationship among the construct level of analogical reasoning, prediction and uncertainty, and the construction of an explanatory model that were produced during small group discussions for scientific problem solving. This study was participated in by 8 students of K University divided into 2 teams conducting scientific problem solving. The participants took part in discussions in groups after achieving scientific problem solving individually. Through individual interviews afterwards, changes in their thinking through discussion activities were looked into. The results are as follows: The analogy at the Entities/Attributes level was used to make people clearly understand the characteristics of certain objects or entities in the discussions. The analogy at the Configuration/Motion level that was produced during the discussions ensured other participants to predict the results of problem solving. The analogy at the Mechanism/Causation level changed the structure of problem situations either to help other participants to reconstruct the explanatory model or to come up with a new situation that was never been through before to justify the created mechanism and through this, the case of creating Thought Experiments during the discussions were observed. if looking into the changes of analogies, each individual's analogic paradigm during the discussions were shown as production paradigm, reception-production paradigm, production-reception paradigm, and reception paradigm. The construction and reconstruction of the explanatory model were shown in analogic production paradigm, and in the reception paradigm of an analogy, participants changed their predictions or their certainty.

• Korean journal of food and cookery science
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• v.21 no.6 s.90
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• pp.867-876
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• 2005

The purposes of this study were, 1) to investigate the causal relationship between customer's life-style and motivation of eating-out, and 2) to research the causal nexus between motivation of eating-out and satisfaction of attributes to choose the restaurant. Reliability analysis, factor analysis, and Structure Equation Model(SEM) were adapted by Windows SPSS 10.0 and Amos 4.0. Life-style was divided into 7 factors and eating-out motivation into 5. Life-style influenced significantly each motivation of eating-out. It had positive influence on 'Reception and congratulation', 'Change of dietary life', 'Economic saving', "'Preference motivation', and 'Advertisement and companion's need', but negative influence on 'Reception and congratulation', 'Change of dietary life', and 'Preference motivation'. Customer's motivation of eating-out also influenced significantly the attributes. Factorl 'Reception and congratulation' had positive influence on all attributes except for 'Transportation convenience and distance to the shop'. Factor 2 'Change of dietary life' had negative influence on 'Food's taste, quantity, price', 'Sanitation and cleanness', and 'Staff's service quality' Factor 3 "Economic saving' had positive influence on 'Food's taste, quantity, price' and 'Transportation convenience and distance to the shop'. factors 'Advertisement and companion's need' had positive influence on 'Atmosphere of restaurant' and negative influence on 'Food's taste, quantity, price'.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.99-106
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• 2017

With the advent of virtual money such as bit coins, interest in the block chain is increasing. Block Chain is a technology that supports Distributed Ledger and is a versatile technology applicable to various fields. Currently, the block chain is conducting research for various applications such as virtual money, trade finance, marketplace, power market, image contents service, and IoT. The technologies that make up the block chain are smart contract, digital signature/hash function and consensus algorithm. And these technologies operate on P2P networks. In this paper, we have studied e-mail system based on the ethereum which is one of the block chain based technologies. Most legacy mail systems use SMTP and the POP3/IMAP protocol to send and receive e-mail, and e-mail use S/MIME to protect the e-mail. However, S/MIME is vulnerable to DDoS attacks because it is configured centrally. And it also does not provide non-repudiation of mail reception. To overcome these weaknesses, we proposed an e-mail system model based on ethereum. The proposed model is able to cope with DDoS attack and forgery prevention by using block chain based technology, and reliable recording and management among block chain participants are provided, so that it is possible to provide a non-repudiation function of e-mail transmission and reception.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1854-1868
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• 2018

A wireless body-sensor network (WBSN) refers to a network-configured environment in which sensors are placed on both the inside and outside of the human body. The sensors are much smaller and the energy is more constrained when compared to traditional wireless sensor network (WSN) environments. The critical nature of the energy-constraint issue in WBSN environments has led to numerous studies on the reduction of energy consumption of WBSN sensors. The transmission-power-control (TPC) technique adjusts the transmission-power level (TPL) of sensors in the WBSN and reduces the energy consumption that occurs during communications. To elaborate, when transmission sensors and reception sensors are placed in various parts of the human body, the transmission sensors regularly send sensor data to the reception sensors. As the reception sensors receive data from the transmission sensors, real-time measurements of the received signal-strength indication (RSSI), which is the value that indicates the channel status, are taken to determine the TPL that suits the current-channel status. This TPL information is then sent back to the transmission sensors. The transmission sensors adjust their current TPL based on the TPL that they receive from the reception sensors. The initial TPC algorithm made linear or binary adjustments using only the information of the current-channel status. However, because various data in the WBSN environment can be utilized to create a more efficient TPC algorithm, many different types of TPC algorithms that combine human movements or fuse TPC with other algorithms have emerged. This paper defines and discusses the design and development process of an efficient TPC algorithm for WBSNs. We will describe the WBSN characteristics, model, and closed-loop mechanism, followed by an examination of recent TPC studies.

• Korean Educational Research Journal
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• v.38 no.2
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• pp.81-108
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• 2017

The purpose of this study is to develop a standardized learning model for a free-learning semester, and to provide a practical framework of its curriculum. This paper is a state-funded study to design an instructional model for the free-learning semester. Instructional models that have been implemented in the practical school were constructed through collecting opinions from school teachers. The instructional model for a free-learning semester in this current study is a modification of the existing learning model into the Learning (Meaningful reception learning)-Practice-Production stage. These are designed to reflect the UNESCO proposals that emphasize knowledge, skills, and character, respectively. It is not easy to construct the instructional model for the free-learning semester activities. A three-step strategy that encompasses the UNESCO proposals will be a useful framework for teachers to systematically design and implement free-learning semester teaching.