• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.1
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• pp.54-58
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• 2017

The effect of low temperature ($250^{\circ}C$) heat treatment after electron irradiation (irradiation time = 30, 180, 300s) on the chemical bonding and electrical properties of ZnO thin films prepared using a sol-gel process were examined. XPS (X-ray photoelectron spectroscopy) analysis showed that the electron beam irradiation decreased the concentration of M-O bonding and increased the OH bonding. As a result of the electron beam irradiation, the carrier concentration of ZnO films increased. The on/off ratio was maintained at ${\sim}10^5$ and the $V_{TH}$ values shifted negatively from 11 to 1 V. As the irradiation time increased from 0 to 300s, the calculated S. S. (subthreshold swing) of ZnO TFTs increased from 1.03 to 3.69 V/decade. These values are superior when compared the sample heat-treated at $400^{\circ}C$ representing on/off ratio of ${\sim}10^2$ and S. S. value of 10.40 V/decade.

• Journal of Powder Materials
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• v.12 no.3
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• pp.192-200
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• 2005

Ultrafine copper powder was prepared from $CuO-H_2O$ slurry with hydrazine, a reductant, under $70^{\circ}C$. The influence of various reaction parameters such as temperature, reaction time, molar ratio of $N_2H_4$, PvP and NaOH to Cu in aqueous solution had been studied on the morphology and powder phase of Cu powders obtained. The production ratio of Cu from CuO was increased with the ratio of $N_2H_4/Cu$ and the temperature. When the ratio of $N_2H_4/Cu$ was higher than 2.5 and the temperature was higher than $60^{\circ}C$, CuO was completely reduced into Cu within 40 min. The crystalline size of Cu obtained became fine as the temperature increase, whereas the aggregation degree of particles was increased with the reaction time. The morphology of Cu powder depended on that of the precursor of CuO and processing conditions. The average particle size was about $0.5{\mu}m$.

• Health Policy and Management
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• v.32 no.4
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• pp.389-399
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• 2022

Background: This study aimed to analyze changes in medical utilization and cost before and after long-term care (LTC) implementation. Methods: We used the National Health Information Database from National Health Insurance Service. The participants were selected who had a new LTC grade (grade 1-5) for 2015. Medical utilization was analyzed before and after LTC implementation. Segmented regression analysis of interrupted time series was conducted to evaluate the overall effect of the LTC implementation on medical costs. Results: The total number of participants was 41,726. A major reason for hospitalization in grade 1 was cerebrovascular diseases, and dementia was the top priority in grade 5. The proportion of hospitalization in grade 1 increased sharply before LTC implementation and then decreased. In grade 5, it increased before LTC implementation, but there was no significant difference after LTC implementation. As for medical cost, in grades 1 to 4, the total cost increased sharply before the LTC implementation, but thereafter, changes in level and trend tended to decrease statistically, and for grade 5, immediately after LTC implementation, the level change was decreasing, but thereafter, the trend change was increasing. Conclusion: Long-term care grades showed different medical utilization and cost changes. Long-term care beneficiaries would improve their quality of life by adequately resolving their medical needs by their grades.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.6 no.3
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• pp.1-7
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• 2007

In this paper, we propose a new prioritized Optical Burst Switching (OBS) protocol based on a hop count, which can provide efficient utilization in optical networks. Under several legacy schemes, a switch drops the burst with the shortest time regardless of its traversed hop count. As a result, a dropped burst that have been traversed many hops might cause increased bandwidth waste compared to one that has traversed a few hops. To improve this problem, we propose the Just Enough Time (JET) with a hop counting scheme which can reduce the wasted bandwidth by prioritizing the burst traversed many hops over others. From the simulation result, it is preyed, we show that the proposed scheme has advantages against legacy schemes in terms of the burst blocking probability and the link utilization.

• Journal of Pharmaceutical Investigation
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• v.23 no.2
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• pp.97-102
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• 1993

Hospital pharmacy services are divided into dispensing affairs for inpatients and outpatients, pharmaceutical service, stock control, intravenous admixture service, drug information service, pharmacokinetic consultation service, education and research work, etc. But among those affairs, dispensing affair for outpatient is perceived as the most important work in Korea, because it is linked directly with hospital service for patients. Therefore, total computer system for dispensing area was adopted from opening point of hospital in 1989 in Asan Medical Center. Utilization of computer system for outpatient dispensing area is as follows; 1) Order communication system of prescription by Total Hospital Information System, 2) Automatic print-out system of direction for use by sticker connected with on-line net work, 3) Use of automatic tablet counting and packaging machines connected with on-line net work. Those computer system resulted in curtailment of pharmacy manpower and shortening of waiting-time for outpatient.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.12
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• pp.101-106
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• 2011

An utilization of electricity usage measured data by region and time through the consumer portal system for building and large consumer are suggested. Electricity usage data by region and time can't be measured by traditional approach. A measured data from smart meters which are installed various regions can be utilized to set up a management of electricity peak demand.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.117-135
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• 2016

Performance enhancement is one of the most important issues in high performance distributed computing systems. In such computing systems, online users submit their jobs anytime and anywhere to a set of dynamic resources. Jobs arrival and processes execution times are stochastic. The performance of a distributed computing system can be improved by using an effective load balancing strategy to redistribute the user tasks among computing resources for efficient utilization. This paper presents a multi-class load balancing strategy that balances different classes of user tasks on multiple heterogeneous computing nodes to minimize the per-class mean response time. For a wide range of system parameters, the performance of the proposed multi-class load balancing strategy is compared with that of the random distribution load balancing, and uniform distribution load balancing strategies using simulation. The results show that, the proposed strategy outperforms the other two studied strategies in terms of average task response time, and average computing nodes utilization.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.4
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• pp.195-200
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• 2009

In this paper, we propose a new priority Optical Burst Switching (OBS) protocol based on a hop count, which can provide an efficient utilization in optical wireless networks. Under several legacy schemes, a switch drops the burst with a shorter time among ones regardless of its traversed hop count. As a result, the dropped burst that have been traversed more hops might cause to waste bandwidth than the one traversed a few hops. Noting that this problem, we propose a Just Enough Time (JET) with a hop count scheme which can reduce the wasted bandwidth by prioritizing the burst traversed more hops over others. The simulation results shows that the proposed scheme has more advantages over the legacy schemes in terms of the burst blocking probability and the link utilization.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.299-311
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• 1990

A computer simulation model is proposed for selecting effective agrees paths and estimating the evacuation time in case of evacuating all the residents of a building to the safe area. The physical structure of a building is formulated into a network. The followings are considered in the model : the congestion effect to the velocity, the behavioral pattern of the evacuees, and the probabilistic nature of the evacuation process. Coded in SLAM II/PC, the simulation model can generate the output such as evacuation time(max, average), utilization of exits, utilization of passages, floor clearance times, and bottleneck information. The "rigorous" validation of the proposed model is not completed yet but remains to be a future research topic.rch topic.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.41-42
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• 2018

Various methods that crash the project completion time have been studied. Line-of-Balance (LOB) is well accepted as a useful method that enables steady resource utilization without frequent hire-and-fire of resources for a project having repetitive units. Existing studies involved in LOB-CPM focuses on thesis such as resource leveling and optimization in construction scheduling community. However, crashing methods are not arrived at a full maturity in LOB scheduling, because no one handles steady resource utilization while keeping activity-relationships. This paper proposes a method that crashes project completion time by hybridizing concurrent engineering and LOB scheduling without using additional resources.