• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.3
• /
• pp.533-540
• /
• 2021

To evaluate the performance of a system, one-dimensional 3-neighborhood cellular automata(CA) based pseudo-random generators are widely used in many fields. Although two-dimensional CA and one-dimensional 5-neighborhood CA have been applied for more effective key sequence generation, designing symmetric one-dimensional 5-neighborhood CA corresponding to a given primitive polynomial is a very challenging problem. To solve this problem, studies on one-dimensional 5-neighborhood CA synthesis, such as synthesis method using recurrence relation of characteristic polynomials and synthesis method using Krylov matrix, were conducted. However, there was still a problem with solving nonlinear equations. To solve this problem, a symmetric one-dimensional 5-neighborhood CA synthesis method using a transition matrix of 90/150 CA and a block matrix has recently been proposed. In this paper, we detail the theoretical process of the proposed algorithm and use it to obtain symmetric one-dimensional 5-neighborhood CA corresponding to high-order primitive polynomials.

• Journal of Information Technology Services
• /
• v.20 no.6
• /
• pp.17-43
• /
• 2021

Currently, various discussions are underway to establish a more advanced management system for public rental housing. Also, it calls for improvement methods for problems arising in management of the current rental housing system. In this regard, this study aims to evaluate determinants that affect user acceptance intention of blockchain technology to implement a new system that complements drawbacks of the current public rental housing system. The study uses the Unified Theory of Acceptance and Use of Technology (UTAUT) as a theoretical model; the study model utilizes three UTAUT variables -performance expectancy, social influence, and Facilitating conditions-, applies security, availability, and reliability that are perceived from blockchain technology as external parameters to facilitate understanding of user acceptance intention of blockchain technology, and evaluates whether innovativeness can regulate the influence of performance expectancy, social influence, and Facilitating conditions on user acceptance intention of blockchain technology. Based on the significant survey result where 274 IT technicians participated, the study applies structural equation modeling to explore structure of user acceptance intention in the blockchain-based management system for public rental housing. As a result, security-reliability and availability are found to factors as determinants for user acceptance intention, affecting implementation of the public rental housing management system, while innovativeness shows no significant statistical results related to regulation effect. This study has implications in that it understands characteristics of blockchain and empirically analyzes the relationship between the characteristics and acceptance intention to enable blockchain's contribution to activate the public rental housing management system in the future.

• Journal of English Language & Literature
• /
• v.56 no.5
• /
• pp.773-796
• /
• 2010

This essay examines, first, the possibility and limitation of Asian America as a category of identity and its political and cultural implications through various theoretical perspectives. Here, by closely reading David Mura's poem "The Colors of Desire," I will argue that "Asian America" as a category of identity is now on the verge of falling apart and its politics of identity is no longer an effective way of fighting back against racism in the US. It is because Asian America is indeed what might be called a historical block, a product of ad-hoc coalition between different ethnic groups historically situated and constructed. In this sense, it is a kind of phantasmal object that is marked by practical absence. This fabricatedness inherent in Asian America as an identity category signifies that it has no essence that is meant to define the group in a transcendental way. The internal totality and coherence of that identity can thus be achieved only by suppressing differences between various ethnic groups and positing a single 'authentic' Asian American identity and culture. More dangerously, according to Viet Nguyen, such idealization of a single subject position can reinforces ideological rigidity that might threaten the ability of Asian America to represent itself in a unified fashion. Then, he predicts, Asian America will lose its cohesive force and fall apart. Eventually, every group within Asian America will be ethnicized. The only way of escaping from this bleak situation, as Vincent Cheng argues, is to foregroud the fabricatedness and ad-hocness of Asian America and to perform "inauthenticity," because Asian America is nothing but a functional category that is marked by absence of essence or authenticity. If Asian Americans admit that they have no essence and that they are essentially inauthentic, the practice of performing inauthenticity can become what we might call an alternative Asian American culture and identity.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.22 no.2
• /
• pp.35-48
• /
• 1985

The present work develops a method of evaluating thrust deduction and wake for different loads of the propeller using the concerted application of the theoretical tools and experimental techniques. It also shows the applicability of the new method to the design of optimum hull form. Firstly, the problem of hull-propeller interaction was analyzed in terms of inviscid as well as viscous components of the thrust deduction and wake. The wavemaking resistance of a hull and propeller were mathematically represented by sources on the hull surface and sink on the propeller plane, respectively. The strength of sink was determined by utilizing the radial distributions of propeller load and nominal wake. The resistance increment due to a propeller and the axial perturbation flow induced by the hull in the propeller plane were calculated. Especially, the inviscid component of the thrust deduction was calculated by subtraction the wavemaking resistance of a bare hull, the wavemaking resistance of a free-running propeller and the augmentation of propeller resistance due to hull action from the wavemaking resistance of the hull with a propeller. The viscous components of the thrust deduction and wake were estimated as functions of propeller load which were established by the propeller load varying test after deduction the calculated inviscid components. Secondly, an analysis method of powering performance was developed based on the potential theory and the propeller load varying test. The hybrid method estimates the thrust deduction, wake and propeller open-water efficiency for different propeller load. This method can be utilized in the analysis of powering performance for the propeller load variation such as the added resistance due to hull surface roughness, the added resistance due to wind, etc. Finally, the hybrid method was applied to the optimum design of hull form. A series of afterbody shapes was obtained by systematically varying the waterplane and section shapes of a parent afterbody without changing the principal dimensions, block coefficient and prismatic coefficient. From the comparison of the predicted results such as wavemaking resistance, thrust deduction, wake and delivered power, an optimum hull form was obtained. The delivered power of the optimized hull form was reduced by 5.7% which was confirmed by model tests. Also the predicted delivered power by the hybrid method shows fairly good agreement with the test result. It is therefore considered that the new analysis method of powering performance can be utilized as a practical tool for the design of optimum hull form as for the analysis of powering performance for the propeller load variation in the preliminary design stage.

• Journal of the Korean association of regional geographers
• /
• v.13 no.3
• /
• pp.301-320
• /
• 2007

In Korean academic societies, old maps has not yet been properly investigated in terms of their genealogy, classification, detailed place names, historical backgrounds and the other aspects. With publication of the bibliographies and papers on old maps reserved in museum and library, the scope of research enlarged gradually its scope from 1970s. In 1980s, with the development of theoretical geography, scientific analysis were applied to investigate the projection method of Daedongyeo-jido. The 1990s proved a prominent decade for researches. The photo-copies of old maps enabled researchers to investigate the in-depth comparative study. The more important thing is that old maps became to be powerful instrument in the research of historical geography, such as territorial disputes and marine name(東海). And county old maps compiled by region became to be regional-cultural contents of local areas. Important issues in old map research in Korean academic societies are about Cheonha-do which is unique old world map in Korea, grid-system projection in old county maps and the genealogy of Daedongyeo-jido(manuscript and block print edition). This study shows that bibliography of all old maps preserved in each library and museum should be standardized. This could enable the exchange of information of old maps between institutes. The more important thing is that conciliation of human, social and natural sciences should be applied in the research of old maps.

• Journal of Biosystems Engineering
• /
• v.26 no.5
• /
• pp.461-468
• /
• 2001

Impact between fruits and other materials is a major cause of product damage in harvesting and handling systems. The oriental pears are more susceptible to bruising than other fruits such as European pears and apples, and are required more careful handling. The interest in the handling of the pears for the processing systems has raised the question of the allowable drop height to which pears can be dropped without causing objectionable damage. Drop tests on pears were conducted using an impact device developed by authors to estimate the allowable drop height without bruising. The impact device was constructed to hold in a selected orientation and to release a fruit by vacuum for dropping on to a force transducer. The drop height was adjustable for zero to 60 cm to achieve the desired distance between the bottom of the fruits and the top of the impact force transducer. The transducer was secured to 150 kg$\sub$f/ concrete block. The transducer signal was sampled every 0.17 ms with a strain gage measurement board in the micro computer where it was digitaly stored for later analysis. The selected sample fruit was Niitaka cultivar of pears which is one of the most promising fruit for export in Korea. The pears were harvested during the 1998 harvest season from an orchard in Daejeon. The sample fruit was selected from two groups which were stored for 3 months and 5 months respectively by the method of current commercial practice. The pears were allowed to stabilize at environmental condition(18$^{\circ}C$, 65% rh) of the experimental room. One hundred fifty six pears were tested from the heights of 5, 7.5. 10 and 12.5 cm while measurement were made of impact peak force, contact time, time to peak force, dwell time, pear diameter and mass. The bioyield strength and modulus of elasticity were measured using UTM immediately after each drop test. The allowable drop height was estimated on the base of bioyield strength of the pears in two ways. One was assumed the peak force during impact test increasing linearly with time, and the other was based on the actual drop test results. The computer program was developed for measuring the impact characteristics of the pears and analyzing the data obtained in the study. The peak force increased while contact times decreased with increasing drop height and contact times of the sample from the hard tissue group. The allowable drop height increased with increasing bioyield strength and contact times, and also varied with Poisson\`s ratio, mass and equilibrium radius of the pears. The allowable drop height calculated by a theoretical method was in the range from 1 to 4 cm, meanwhile, the estimated drop height considering the result of the impact test was in the range from 1 to 6 cm. Since the physical properties of fruits affected significantly the allowable drop height, the physical properties of the fruits should be considered when estimating the allowable drop height.

• Korean Journal of Optics and Photonics
• /
• v.9 no.2
• /
• pp.111-116
• /
• 1998

Thirteen InGaAs/InGaAsP separate-confinement heterostructure multiple quantum well lasers were designed such that the strain in the active layer from 0.9% compressive strain to 1.4% tensile, and their threshold current density was caluculated to see the effects of strain on the threshold current density. The well width was adjusted such that the bandgap of the quantum well is 1.55 ${\mu}{\textrm}{m}$, For the calculation of the band structure and transition matrix element needed for the gain calculation, a block diagonalized 8$\times$8 second-order $\to{k}.\to{p}$ Hamiltonian was used to incorporate the conduction band nonparabolicity and the valence band mixing. The threshold current density shows discontinuity at 0.4% tensile strain where the first heavy-hole subband and the first light-hole subband cross and at 0.5% tensile strain where the second conduction subband begins to exist. The threshold current density at room temperature has a maximum around these 0.4-0.5% tensile strains, and as strain varies in either direction it decreases first and then increases a little after a local minimum. This calculated trend is consistent with the other reported experimental results. We discussed the results of this calculation in comparison with other theoretical or experimental papers on the effect of strain.

• The Journal of the Korea Contents Association
• /
• v.21 no.3
• /
• pp.103-113
• /
• 2021

Rather than a directing method of existing animations, VR animation needs a different method of direction. Existing animations were displayed on a screen in movie theaters. But using an existing direction method for the 360° perspective in a VR animation makes it difficult for the user's gaze to move in a way the directors have intended. I analyzed 3 VR animations with a theoretical background of Rudolf Arnheim's visual perception theory and Bruce Block's visual factors that bring high attention. In the process of perception of space, focus on the gaze, movement of the gaze, the 'movement' factor was used most often to attract the gaze. An interactive VR animation attracts user's gaze by allowing users to participate in important points of the story. With an analysis of the animation, it proposed a gaze attraction through the movement of the character with an interaction directing method for reducing motion sickness. Also, it proposed intuitively attracting gaze movement by using GUI and attracting user's participation by using an interactive event with an interaction directing method of storytelling comprehension. With two types of directing proposal, we expect it to be utilized as a basic research method for attracting users to be immersed in storytelling while reducing cyber motion sickness, which is a problem in VR animation.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.6
• /
• pp.179-191
• /
• 2021

Social anxiety continues due to the emergence and spread of covid-19 infections. In this situation, false information related to the covid-19 infection is distributed through SNS in the form of fake news, which is a stumbling block to overcoming the national crisis. This study tried to present a theoretical basis for the establishment of policies for the regulation and eradication of fake news circulated through SNS by examining the effect of social anxiety on the fake news acceptance attitude by focusing on the use degree of SNS. For this study, a survey of 380 university students in the Seoul metropolitan area was conducted, and 336 data collected among them were analyzed as SPSS 25.0 and AMOS 23.0. According to the analysis results, social anxiety has a positive effect on the fake news acceptance attitude and the use degree of SNS, also the use degree of SNS has a positive effect on the fake news acceptance attitude. In addition, social anxiety has been confirmed to have a positive effect on fake news acceptance attitude through the use degree of SNS. These results empirically confirm the relationship between social anxiety, fake news acceptance attitude, and the use degree of SNS.

• Communications of Mathematical Education
• /
• v.37 no.3
• /
• pp.517-544
• /
• 2023

This study presents the process and outcomes of developing mathematical-informatics linkage·convergence class materials, based on previous research findings that indicate a lack of such materials in high schools despite the increasing need for development of interdisciplinary linkage·convergence class materials In particular, this research provides insights into the discussions of six teachers who participated in the same professional learning community program, aiming to create materials that are suitable for linkage·convergence class materials and highly practical for classroom implementation. Following the material development process, a theme-based design model was applied to create the materials. In alignment with prior research and consensus among teacher learning community members, mathematics and informatics teachers developed instructional materials that can be utilized together during a 100-minute block lesson. The developed materials utilize societal issue contexts to establish links between the two subjects, enabling students to engage in problem-solving through mathematical modeling and coding. To increase the validity and practicality of the developed resources during their field application, CVR verification was conducted involving field teachers. Incorporating the results of the CVR verification, the finalized instructional materials were presented in the form of a teaching guide. Furthermore, we aimed to provide insights into the trial-and-error experiences and deliberations of the developers throughout the material development process, with the intention of offering valuable information that can serve as a foundation for conducting related research by field researchers. These research findings hold value as empirical evidence that can explore the applicability of teaching material development models in fields. The accumulation of such materials is expected to facilitate a cyclical relationship between theoretical teaching models and practical classroom applications.