• Journal of Industrial Convergence
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• v.22 no.4
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• pp.1-9
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• 2024

Smart factories represent production facilities where cutting-edge information and communication technologies are fused with manufacturing processes, reflecting rapid advancements and changes in the global manufacturing sector. They capitalize on the integration of robotics and automation, the Internet of Things (IoT), and the convergence of artificial intelligence technologies to maximize production efficiency in various manufacturing environments. However, the smart factory environment is prone to security threats and vulnerabilities due to various attack techniques. When security threats occur in smart factories, they can lead to financial losses, damage to corporate reputation, and even human casualties, necessitating an appropriate security response. Therefore, this paper proposes a security authentication mechanism for safe communication in the smart factory environment. The components of the proposed authentication mechanism include smart devices, an internal operation management system, an authentication system, and a cloud storage server. The smart device registration process, authentication procedure, and the detailed design of anomaly detection and update procedures were meticulously developed. And the safety of the proposed authentication mechanism was analyzed, and through performance analysis with existing authentication mechanisms, we confirmed an efficiency improvement of approximately 8%. Additionally, this paper presents directions for future research on lightweight protocols and security strategies for the application of the proposed technology, aiming to enhance security.

• Geomechanics and Engineering
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• v.37 no.6
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• pp.599-614
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• 2024

To evaluate the safety status of deteriorated segments in a submarine shield tunnel during its service life, a seepage model was established based on a cross-sea shield tunnel project. This model was used to study the migration patterns of erosive ions within the shield segments. Based on these laws, the degree of deterioration of the segments was determined. Using the derived analytical solution, the internal forces within the segments were calculated. Lastly, by applying the formula for calculating safety factors, the variation trends in the safety factors of segments with different degrees of deterioration were obtained. The findings demonstrate that corrosive seawater presents the evolution characteristics of continuous seepage from the outside to the inside of the tunnel. The nearby seepage field shows locally concentrated characteristics when there is leakage at the joint, which causes the seepage field's depth and scope to significantly increase. The chlorine ion content decreases gradually with the increase of the distance from the outer surface of the tunnel. The penetration of erosion ions in the segment is facilitated by the presence of water pressure. The ion content of the entire ring segment lining structure is related in the following order: vault < haunch < springing. The difference in the segment's rate of increase in chlorine ion content decreases as service time increases. Based on the analytical solution calculation, the segment's safety factor drops more when the joint leaks than when its intact, and the change rate between the two states exhibits a general downward trend. The safety factor shows a similar change rule at different water depths and continuously decreases at the same segment position as the water depth increases. The three phases of "sudden drop-rise-stability" are represented by a "spoon-shaped" change rule on the safety factor's change curve. The issue of the poor applicability of indicators in earlier studies is resolved by the analytical solution, which only requires determining the loss degree of the segment lining's effective bearing thickness to calculate the safety factor of any cross-section of the shield tunnel. The analytical solution's computation results, however, have some safety margins and are cautious. The process of establishing the evaluation model indicates that the secondary lining made of molded concrete can also have its safety status assessed using the analytical solution. It is very important for the safe operation of the tunnel and the safety of people's property and has a wide range of applications.

• The Journal of Fisheries Business Administration
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• v.17 no.2
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• pp.65-106
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• 1986

1, The Purpose of Study This is a study on the Evaluation of the operating of Fisheries Extension Services of Korea, for performing the activities such as guiding fisheries technique as well as offering industrial information to the fishermen in fishing village. By doing so, the Fisheries Extension Sevices(FES) can materialize the continued growth of fisheries, the social and economic development of fishing village, and the increase in income by enhancing the knowledge level of Fishermen, etc. In performing fisheries policy, this activity plays a great role on the research and development activity, and it has become practical since 1976 in Korea. In order to meet immediately with the problem of fisheries technical innovation and rapid environmental changes surrounding the fisheries, the fishermen should not only enhance their scientific and comprehensive capacity in fisheries technique but abtain various effective information. Generally, as most of all the fishemen are poor in the managerial structure and scattered in fishing villages, they have little opportunity in the contact of information. As a result, it is nessessary for the FES to perform the fishing business by the extension service officials who has received special training and acquired fisheries know-how in these fields. And yet, FES is under the unfullfilled circumstance in such factors as manpower, technical know-how, equipment, and the service system etc., which is required in promoting the social, economic development of fishing village and in resolving the high technique demand of fisherman. This study on the fisheries extension services have been studied from those backgrounds. 2. Research Method The data of collecting methods which were necessary in carrying out this study was adopted by the questionaire research on the present extension service activity, through the subject of the extension services (driving agency of the work and the officials), the object(fishemen) and the 3rd observers to the extension services (the authorities concerned). The research sample was taken by the sampling extraction of total 1, 774 men from the above 3 groups. And the research was carried out from August, 1986 to October, 1986, supported from the Fisheries Extension Office (FEO) located in field during the research process. In this study, the levels of the extension operating were determined and estimated in accordance with the extension service method, morale of extension service officials and the extension service system, etc. through the collected data of the research questionaire paper. And based on this result, the essential conditions of the extension services were grasped, and also we tried to present the various activity plan necessary to promote the operating of the extension services. The questionaire research data was calculated by the computer center of National Fisheries University of Pusan, and the total result was again tried on the one demension analysis along with two dimension analysis to search out the relativity between the questionaire, and the statistical test was done $\chi$$^2$test in significance level of l~5%. 3. Contents of Study This study consists of 7 chapters and the contents are as follows : Chapter I : The object and method of the study Chapter II : The assessment and analysis of the extension services Chapter III : The contents and method of the extension services Chapter IV : Analysis of the essential conditions for the extension services Chapter V : The evaluation of activities of extension services Chapter Ⅵ : Conclusion.4. Results and RecommendationTherefore, the results of this study estimated by logical process and analysis are as follows : 1) Most of Korean fishing villages and coastal fishermen have shown much concerns about fisheries technique and social changes, thus many of them were confronted with new problems on how to adapt and to meet changes. 2) Majority of fishermen estimated FEO as an organization of specific technologies with all the thing concerning the fisheries technique in general. Therefore the fishermen wanted to utilize the FEO as an adaptable method for the modern fisheries techniques as well as the environmental changes. 3) In contrast with the fast changes of the fisheries technique, the complexity and variety of technical system and the broadness of fishing village and fishermen, it was revealed that the necessary factors such as the facilities, manpower, budget, and the level of applying techniques of the FEO located in field were highly insufficient. Accordingly, the guiding efficiency was low and the extension services did not provide full solution to the various request from fishermen. 4) It is possible to classify the activation factor for the extension service into two large dimension ; personal dimension relevant to guidance officials and work dimension relevant to the organization. And it was found that the activation level of the work dimension was far lower than the personal dimension between them. So, the activation should be done first in the dimesion to promote the activation of the extension services. 5) The extension services officials are now demoralized in general, thus it is necessary to take reality into consideration : the expense of activity, the adequate endowment of activity scope and the reasonable operation of the position class, etc to enhance its morale. However, in order to do the FES activation, first of all, the systems should be established which is lain unsettled stage until now. And there must be change in the understanding of government i.e. the fisheries extension services are the essential policy subject to build up the base of fisheries growth and modernize the fisheries management. And it should be driven positively with the recognition of the "lasting project".g project".uot;.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.2 no.1
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• pp.178-210
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• 1974

It needs to put into practice the systems analysis in the analysis of some operations and status of library for the purpose of systematizing the work of reforming in the new easier form to process, to storage, to retrieve and to make use of the increasing informations and data of library. In this study, some of systems which are generally using in every library was caught in the case study of K university library. Having analyzed them with the two methods of the flowcharting and mathematical analysis, we found the obstructive factors in operation. As the result of this research, it was gained the new system as the alternative one. A. Alternative System B. Advantages of alternative systems 1. In the reference room When it converts the present system into the new system, it can profit 6.771 won/user (13.815won-7.044won=6.771 won). Therefore, a half the average required cost of the present system can be saved. If this saving would be alloted for the cost 33,000won required to make the cataloging cards, it would be taken for 94 days (33,000 won ${\div}$ 6,771 won/user=4,874users. 4,874users ${\div}$ 52users/day=94days) to get it. The saving cost/year by the new system will be 95,417 won, and in the first year the initial cost (33,000won) reduces the saving cost to 62,417won. 2. In the periodical room The average required time for using the materials of the present system is 17 minutes/user and the average required cost/user is 23.775won, while the average required time of the new system is 4 minutes and the average required cost/user is 5.33won. Therefore, the new system has profit 4 times of the present system. Accordingly, it occurs when the dispersed periodical materials get together. 3. In the classification and cataloging When one processes - the oriental books - by the Linear Programming Technique, the maximum of the process can be increased from 11.6 volumes per librarian of the present system to 12 volumes per librarian of the new system increased 0.4 volume in a day, and cataloging by the manual printer can be shorten from 3 minutes per card of the present system to 1.5 minutes per card of the new system. Consequently, we can complete the other operations (books equipment, updating of cataloging cards, etc.) with 141 minutes which are saved in the course of the afore-mentioned works. 4. In the status of collections The average growth rate of 4 years from 1968 to 1971 is 9.825 %, and that of the purchased materials is 6.2% similar to the advanced nations, but it has the different position from 215,000 volumes by the Standard Degree for Establishment of College and University, and the difference between the total collections 151,671 volumes and Dunns' growth model ($N_t=N_oe^{-at}$) claimed by Leimkuhler 155,297 volumes in 1971 is 3,626 volumes, and for the purpose of compensation the difference, we found the fact that it needs to have the increased budget of 24~30% per year, Thus, if the budget of 24~30 % per year. Thus, if the budget would be increased per year as the rate of the afore-mentioned figure, it would be reached at the Standard Degree for Establishment of College and University in 1975, and thereafter, it can be decreased to the lebel which is able to maintain the growth rate of 5~6% per year.

• Economic and Environmental Geology
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• v.34 no.3
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• pp.271-281
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• 2001

The characteristics of the heavy metal contamination in the soils affected by the tailings of the Palbong mine have been studied. The soils in the studied area consist mostly of loam by the particle size analysis, but a little of it, located near the stream, consist of loamy sand to sandy loam, finally to loam downward. The organic contents of soils are significantly low aoom 2 percent and the pH is in acidic ranging 6.0 $\pm$ 0.1. The samples of the parent rocks, the normal soils, the tailings and the channel deposits from the studied area were chemically analysed. From the result, the heavy metal concenlration of the soils is a little Jow compared with that of the parent rocks, shows the hydrologic process of the surface and the groundwater. The contamination of the tailings from the ore mining are high in lead, copper and arsenic. In the channel deposits the concenlrations of lead and copper are abnormally high but that of arsenic is uniquely low. And most of heavy metal contamination are decreased with the distance from the mine. It is caused by the properties of the surface and the ground water during the process of the heavy metal migration. The correlation-coefficient between sand and silt contents and the concentrations of Cd, Cu and Pb are significant but the amounts of As and Hg are increased with the clay contents. The dispersion of the heavy metals with the distance shows that the concentrations of them in the soils sampled at distance of 100 m to 200 m along the stream started near the Palbong mine are extremely high compared with those from other distances. These discrepancies are significant in Cd, Cu, Pb and Hg, but low in As. All the samples contain below detection limit of Cr+6 In the present stream water the concentrations of the heavy metals are not detected. So, it is interpreted that the concentrations in the soils are caused by the activities of the mining during the operation and have been continued by the dispersion from the tailings since after the closure of the mining, especially by the surface and ground water. The concentrations are diminished with the distance from the mining site, but in the interval of 800-2000 m increases abruptly. In the soil samples counted on the dispersion direction by wind, the lowering of the concentration is relatively uniform with the distance from the mining site. So, the rapid increase of the heavy metal concentrations is presumed to have been caused by the ground-water movement. In the migration of the heavy metals, the groundwater conditions, such as pH, Eh, the contents of colloidal particles, and Mn and Fe oxides are closely involveo. Integrating with these factors, it is interpreted that the groundwater conditions which have caused the heavy metal contamination of the studied area are those that the pH is about 3 in oxidized conditions, the contents of the colloidal particles are low, and Mn and Fe oxides are not involved in the migration of the heavy metals. Meanwhile, the vegetables growing on the soils in the studied area are not affected by the contamination of the heavy metals.

• Archives of design research
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• v.18 no.2 s.60
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• pp.155-164
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• 2005

Home-service robots need to have sufficient spatial information about the surroundings for interacting with human intelligently and performing services efficiently. It is very important to investigate the efficient interaction style that supports map building task through human-robot collaboration. We first analyzed map building task with a cleaning robot and drew 4 design factors and tentative solutions, including map building procedure (task-preferred procedure/space- preferred procedure), LCD display installation (robot/robot+remote control), navigation method (push type/pull type), feedback modality(GUI/GUI+TTS). The design factors and tentative solutions were defined as independent variables and levels. This research investigated how those variables affect to the human task performance and behavior in map building tast. 8 kinds of experiment prototypes were built and usability test among 16 house wives was conducted for acquiring empirical data. As the experiment result, in terms of map building procedure, space-preferred procedure indicated better task performance than task-proffered procedure as we expected. For the LCD display installation factor, remote control with LCD display indicated higher task performance and subjective satisfaction. In robot navigation method, it was very difficult to find a significant difference between push type and pull type which contrary to our expectation. In fact, push type indicated higher subjective satisfaction. Also in feedback modality, we have acquired negative feedback an additional TTS operation guidance. It seems that robot's autonomy before achieving spatial information is rudiment condition which means users are just interacting with a mobile appliance. Thus they prefer remote-control-based interaction style in robot map building process as they used in traditional appliance control.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.7
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• pp.721-728
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• 2008

DBPs(Disinfection By-Products) are most formed through the reactions between chlorine and NOM(Natural Organic Matter) in water treatment. In this study, occurrence of DBPs including THMs(Trihalomethanes) is evaluated. Also, influencing factors by the seasons and raw water quality were investigated for correlation among them and the characteristics of THMs formation by prechlorination process. This study investigated the operation condition for THMs removal depending on raw water quality. Water treatment plant from intake station to gauging well flows for about 10 hours in Y Water Supply Office. It is limited to control of THMs formation because of excessive reaction time between chlorine and THMs precursors in the intake station. Therefore, as multi-points prechlorination from intake station to gauging well, THMs formation was decreased in the water treatment, and it was willing to prevent overdosage of chlorine. The concentration of THMs was 0.021 mg/L in the summer, 0.015 mg/L in the winter, respectively. Also, THMs formation showed that 0.013 mg/L in the water of gauging well after prechlorination, 0.014 mg/L in the flocculation/sedimentation/filtration, 0.016 mg/L in the water after postchlorination, respectively. THMFP(Trihalomethane Formation Potential) removed 42.7% and 50% through the flocculation/sedimentation and filtration, respectively, and it is similar TOC removal efficiency. In this study, multi-points prechlorination from intake station to gauging well decreases in contact time and concencrations of NOM and chlorine. Also, it decreases in THMs and amount of chlorine uesd. In the result of multi-points prechlorination in the summer, the concentration of THMs was 0.013mg/L in the treated water. In view of these facts, THMs formation can be decreased approximately 50%.

• Journal of the Korean Geographical Society
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• v.48 no.1
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• pp.87-111
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• 2013

Regional disparities between eastern and western regions is the most of serious problem for balanced regional development in Turkey. The Southeastern Anatolia Project (GAP) is being implemented to eliminate these regional development disparities. The work that was initially planned as predominantly for hydraulic energy production to utilize water resources of the Tigris and Euphrates rivers more effectively was later transformed into an integrated multi-sector regional development project. This study noted that this region had very limited cash crop production because of the constraints of semi-arid climate of the southeastern region, however, later, it has changed Turkey's major cotton producing region since Southeastern Anatolia Project carried out. Therefore, this study investigated background, process, and content of the Southeastern Anatolia Project with respect to high cotton productivity in this region and examined the dynamic changes of cotton productivity in this region. In addition, Sanliurfa prefecture is one of the main development axes of the Southeastern Anatolia Project, because government investments are concentrated on this prefecture. Therefore, this study examined the background and process of cotton farming growth in this prefecture. In 2011, Sanliurfa prefecture produced 37.6% of Turkey's total cotton production. This is mainly due to agricultural infrastructure expansion such as land consolidation, irrigation, roads and farm roads. Also, it is one of the main factor that subsidies paid to farmers for cotton cultivation. The introduction of irrigation has dramatically changed the direction of seasonal migration of this area. Prior to irrigation, this area had a serious social issue about out-migration for seasonal labor to other areas. However, the introduction of irrigation made this area that changed to in-migration and intramigration for cotton cultivation. Irrigation water is supplied to farmers through the WUAs (Water User Associations) that handed over irrigation water management, operation from DSI (General Directorate of State of Hydraulic Works). However, the WUAs are under the influence of Ashiret, a traditional feudal social structure. Because of this reason, it does not have an efficient management for farmers. Also, it is one of the reasons that this area does not have autonomous farmer organization.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.451-464
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• 2008

Three-phase inverse fluidized bed has been widely adopted with its increasing demand in the fields of bioreactor, fermentation process, wastewater treatment process, absorption and adsorption processes, where the fluidized or suspended particles are small or lower density comparing with that of continuous liquid phase, since the particles are frequently substrate, contacting medium or catalyst carrier. However, there has been little attention on the three-phase inverse fluidized beds even on the hydrodynamics. Needless to say, the information on the hydrodynamics and transport phenomena such as heat and mass transfer in the inverse fluidized beds has been essential for the operation, design and scale-up of various reactors and processes which are employing the three-phase inverse beds. In the present article, thus, the information on the three-phase inverse fluidized beds has been summarized and reorganized to suggest a pre-requisite knowledge for the field work in a sense of engineering point of view. The article is composed of three parts; hydrodynamics, heat and mass transfer characteristics of three-phase inverse fluidized beds. Effects of operating variables on the phase holdup, bubble properties and particle fluctuating frequency and dispersion were discussed in the section of hydrodynamics; effects of operating variables on the heat transfer coefficient and on the heat transfer model were discussed in the section of heat transfer characteristics ; and in the section of mass transfer characteristics, effects of operating variables on the liquid axial dispersion and volumetric liquid phase mass transfer coefficient were examined. In each section, correlations to predict the hydrodynamic characteristics such as minimum fluidization velocity, phase holdup, bubble properties and particle fluctuating frequency and dispersion and heat and mass transfer coefficients were suggested. And finally suggestions have been made for the future study for the application of three-phase inverse fluidized bed in several available fields to meet the increasing demands of this system.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.168-174
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• 2011

Various La-based perovskite catalysts were prepared by a Pechini method, and they were applied to the low-temperature oxidation of odor compounds exhausted from waste food treatment process for effective deodorization. Quantitative and qualitative analyses of exhausted gas were conducted to measure the amount of major odor compounds with respect to operation time. A standard odor sample composed of major odor compounds was then prepared for use as a feed for oxidation reaction system. Various transition metal(M)-substituted La-based perovskite catalysts ($LaMO_{3}$: M=Cr, Mn, Fe, Co, and Ni) were prepared and applied to the oxidation of odor compounds in order to investigate the $LaNiO_3$ catalyst showed the best catalytic performance. Pt-substituted perovskite catalysts ($LaNi_{1-x}Pt_{x}O_{3}$: x=0, 0.03, 0.1, and 0.3) were then prepared for enhancing the catalytic performance. It was found that $LaNi_{0.9}Pt_{0.1}O_{3}$ catalyst served as the most efficient catalyst. Supported perovskite catalysts ($XLaNi_{0.9}Pt_{0.1}O_{3}/Al_{2}O_{3}$: X=perovskite content(wt%), 0, 10, 20, 30, 40, 50, and 100) were finally applied for the purpose of maximizing the catalytic performance of perovskite catalyst in the low-temperature oxidation reaction. Catalytic performance of $XLaNi_{0.9}Pt_{0.1}O_{3}/Al_{2}O_{3}$ catalysts showed a volcano-shaped curve with respect to perovskite content. Among the catalysts tested, $20LaNi_{0.9}Pt_{0.1}O_{3}$/$Al_{2}O_{3}$ catalyst exhibited the highest conversion of odor compounds of 88.7% at $180^{\circ}C$.