• Journal of the Korean Magnetics Society
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• v.10 no.5
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• pp.232-236
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• 2000

CoSm thin films with a Cr underlayer have received continuous attention as a potential material for a high density longitudinal magnetic recording media. In this study the Ax gas sputtering pressure effects on the magnetic properties of CoSm thin films, which were fabricated by using a dc magnetron sputtering machine, were investigated. The magnetic switching volume is especially important parameter to understand the thermal stability of the written information, magnetization reversal process and media noise. Therefore, in this paper the effects of sputtering pressure on the magnetic switching volume of CoSm thin films grown on Cr underlayer with the same sputtering conditions was studied. As the Ar sputtering pressure during sputtering of the CoSm magnetic layer increases from 5 to 30 mTorr, the measured switching volumes decreased from 9.0 to 5.2$\times$10$^{-18}$ cm$^3$. The calculated diameter of switching unit from V＊ was less than 22 nm, which satisfies the Sharrock's requirement on the thermal stability of the high density longitudinal magnetic recording media.

• Polymer(Korea)
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• v.27 no.1
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• pp.61-68
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• 2003

In this study, we have investigated the preparation of mixed bead and fiber type hybrid ion-exchanger for recovering nickel ion from plating rinse water. There was little dependence of adsorption capacity for nickel ion on the mixing ratio of resin type and fiber type of ion exchangers. However, it increased with increasing the resin content in the mixed bed. It was shown that the data Langmuir and Freundlich's adsorption isotherm model were well fitted to the linear. Affinity between the functional groups in the ion exchanger and nickel ion in the process was confirmed. The pressure drop decreased with increasing the number of stage in the multistage bed, but it increased with increasing the resin content in the mixing bed. The initial breakthrough time in the multistage bed was short due to the increase of number of stage in the continuous process. It was found that the final breakthrough time of the multistage bed was little changed. The breakthrough time decreased with increasing the amount of fibrous ion exchanger in the mixed bed. The maximum adsorption capacities of the mixed and multistage beds were 2.51 meq/g and 2.69 meq/g, respectively. The desorption time for the nickel ion with $1N H_2SO_4$ solution was lower than 10 minutes and the yield of desorption was greater than 98 percent.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.805-808
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• 2010

In this paper, CdS thin films, which were widey used window layer of the CdS/CdTe and the CdS/$CuInSe_2$ heterojunction solar cell, were grown by chemical bath deposition, and effects of temperature of reaction solution on the structural properties were investigated. Cadmium acetate and thiourea were used as cadmium and sulfur source, respectively. And ammonium acetate was used as the buffer solution. The reaction velocity was increased with increasing temerature of reaction solution. For temperature <= $85^{\circ}C$, as increasing temperature of solution, deposition rate of CdS films was increased by ion-by-ion reaction in the substrate surface, and the crystallinity of the films was improved. However, for temperature <= $55^{\circ}C$, deposition rate was decreased resulting from smaller Cd2+ ion, and the grain size was decreased.

• Journal of Korea Port Economic Association
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• v.23 no.2
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• pp.41-61
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• 2007

After the joining in the WTO of China, the container throughputs have begun to increase notably and Continuous developments of China ports are influencing operation and policy of Korea ports. At this point Pyeongtaek Dangjin port which has potency as China trading port confronts with turning point of port development as new port. To this, correct need grasping of North China shippers is important strategic element of PyeongTaek Dangjin Port activation. In this study, there is purpose to present Pyeongtaek Port's activation strategy by grasping customer needs executing questionnaire to China local company about Pyeongtaek Dangjin Port. As a research result, Pyeongtaek Dangjin Port possesses high geographical strength but has problems like development delay, tribe of various route, absence of marketing strategy. To solve this problem, this paper proposes expansion of port and logistics physical distribution equipment, improvement of services, foundation of joint logistics center, establishment of marketing organization etc. Namely, it may overcome only new port's limitation though develop to port of cargo creation style that is not simple cargo dependence style port.

• Journal of the Korea Society of Computer and Information
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• v.11 no.3
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• pp.67-72
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• 2006

Because computer system is complex gradually from fast growth of the Internet and sudden increase of Internet user and scale is growing, and dependence for computer system is rising gradually, data damage by mistake or disaster is big enough to can not imagine. Usually is continuous if wish to inform through internet and must update data stably, we should manage so that precious data is not erased from sudden problem through periodic backup. Plan to protect data safely for this should be readied. This paper proposes system that can make effective backup environment because consider environment and achievement method in these data management side. That is, implements system that achieve data backup and restore selectively in internet. Backup and restore about data had stored through browser even if disconnect directly to server because it is possible connect in internet by advantage of proposing system are available. Also, This system can manage data stored to server more efficiently by using selectively both backup and restore two methods.

• Atmosphere
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• v.31 no.2
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• pp.185-198
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• 2021

In this study, we examined a spatial downscaling method based on Gradient and Inverse Distance Squared (GIDS) weighting to produce high-resolution grid data from a numerical weather prediction model over Korean Peninsula with complex terrain. The GIDS is a simple and effective geostatistical downscaling method using horizontal distance gradients and an elevation. The predicted meteorological variables (e.g., temperature and 3-hr accumulated rainfall amount) from the Limited-area ENsemble prediction System (LENS; horizontal grid spacing of 3 km) are used for the GIDS to produce a higher horizontal resolution (1.5 km) data set. The obtained results were compared to those from the bilinear interpolation. The GIDS effectively produced high-resolution gridded data for temperature with the continuous spatial distribution and high dependence on topography. The results showed a better agreement with the observation by increasing a searching radius from 10 to 30 km. However, the GIDS showed relatively lower performance for the precipitation variable. Although the GIDS has a significant efficiency in producing a higher resolution gridded temperature data, it requires further study to be applied for rainfall events.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.6
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• pp.841-848
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• 2021

The purpose of this study was to explore what factors influenced users using smartphones in their decision making. In this study, intimacy/personal connectivity, use/dependence, familiarity/professionalism, efficacy/effectiveness, self-identity, control, etc. were set as independent variables and decision-making as dependent variables. In this study, 200 smartphone users were collected and analyzed through a questionnaire, and a nonlinear analysis method using WarpPLS software was utilized to identify the effects between variables. As a result, this study confirmed that factors in smart phone ownership (SPO) could affect individual decision-making and identify that users' psychological factors in the use of smart devices would be directly related to the outcome of decision-making. Through this, it is possible to understand the development of future industries and the acceptability of users using smart devices. and will be meaningful research in tourism, new product development, or continuous brand development.

• Journal of Photoscience
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• v.9 no.2
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• pp.154-157
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• 2002

Direct, continuous, and accurate measurements of solar ultraviolet irradiance (290-400 nm: UVR) have been carried out since 1990, by using both band-spectral ultraviolet-B (290-320 nm: UV-B) and ultraviolet-A (320-400 nm: UV-A) radiometers at Tokai University in Hiratsuka, Japan (35$^{\circ}$N, 139$^{\circ}$E). From our observations, the following findings are provided: 1) an increasing trend in solar UV -B from Oct. 1990 to Sept. 2000; 2) a regional comparison of solar UVR in Japan; 3) the distinct characteristics of UV-B and UV-A irradiance, such as diffuse property, daily and seasonal variation; and 4) human body protection against solar UVR. An increasing 10-year trend in global solar UV - B in Hiratsuka corresponded to a decrease in the total ozone amount measured at Tsukuba (36$^{\circ}$N, 140$^{\circ}$E), giving supportive evidence for a direct link between these two parameters. Furthermore, a strong correlation was found between solar UV-B and total ozone amount from results of UVR measurements at four Tokai University monitoring stations dispersed throughout Japan. Additional results revealed different diffuse properties in global solar UV and in global solar total (300-3000 nm: Total) irradiances. For example, in the global UVR, the diffuse component was dominant: about 80 % independent of weather, with more than 60 % of global UV-B, and more than 50% of global UV-A with even a cloudless clear sky. On the other hand, the portion of the diffuse in the global total irradiance was very low, less than 10 % on a cloudless clear day. Daily and seasonal variations of UV -B and UV -A irradiances were found to be quite different, because of the marked dependence of UV -B irradiance on the atmospheric ozone amount. Moreover, UV -B irradiance showed large daily and seasonal variations: the ratio between maximum and minimum irradiances was more than 5. In contrast, the variation in UV-A was small: the ratio between maximum and minimum was less than 2. Three important facts are proposed concerning solar UVR protection of the human body: 1) the personal minimal erythema dose (MED); 2) gender based difference in MED values; and 3) proper colors for UVR protective clothing.

• Communications of Mathematical Education
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• v.30 no.3
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• pp.375-392
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• 2016

The purpose of this study is to provide a philosophical reflection on mathematical process consistently emphasized in our curriculum and to stress the importance of sharing creativity and its applicability to the mathematical process with the value of sharing and participation. For this purpose, we describe five stages of changing process in a peer mentoring teaching method conducted by a teacher who taught this method for 17 years with the goal of sharing creativity and examine components of mathematical process and their impact on it in each stage based on learning environment, learning process, and assessment. Results suggest that six principles should be underlined and considered for students to be actively involved in mathematical process. After analyzing changes in the five stages of the peer mentoring teaching method, the five principles scrutinized in mathematical process are the principles of continuous interactivity, contextual dependence, bidirectional development, teacher capability, and student participation. On the basis of these five principles, the principle of cooperative creativity is extracted from effective changes of mathematical process as a guiding force.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.820-829
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• 2020

This study was conducted to investigate the anti-oxydant and anti-winkle efficacy as cosmetics ingredient of Lysimachia christinae Hance. Recently, the study of wrinkle improvement of natural products has received continuous interest. so we looked at relationship between reactive oxygen species (ROS) generation and pro-collagen synthesis and matrix metalloproteinases (MMPs) through this study. L. christinae Hance were extracted with 70% ethanol (LcHE) and distilled water (LcHW), respectively, and the experiment was conducted. LcHE had better ROS inhibition effect than LcHW and showed no toxicity up to 250 ㎍/mL concentration as a result of MTT assay in HaCaT cells, so we selected LcHE and conducted the wrinkle improvement material study. We confirmed that the synthesis of type-1 pro-collagen reduced by UVB is activated through pro-collagen synthesis assay. we confirmed that LcHE inhibited the increase in MMP-1 -3 -9 of MMPs induced by UVB in skin cells through western blot and we also performed real-time PCR to confirm the effect of the extract with dependence of concentration at mRNA levels. Therefore, it is expected that Lysimachia christinae Hance is used as a natural material for cosmetics that can effectively prevent wrinkles and skin aging by UVB.