• IE interfaces
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• v.25 no.2
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• pp.196-203
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• 2012

In the postal delivery service, both the standardization of business process and the workload measurement is very important part of saving the cost and improving the efficiency. However, these are not easy to apply to real situation because of the labor-intensive and diversification of delivery environment. In this study, we develop the methodology for the standardization of business process and workload measurement model of the postal delivery service. Firstly, we introduce the work factor analysis on the postal delivery process. Then, we propose the methodology workload measurement model based on diversification of delivery environment.

• International Journal of Computer Science & Network Security
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• v.21 no.12spc
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• pp.443-450
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• 2021

The study is devoted to the formation of a economic principles cargo delivery management in global supply chains. Mathematical model of delivering special categories of goods by road is a key element of these principles. The article analyzes the existing studies on solving the problem of cargo delivery in various aspects. It was noted that the greatest attention is paid to legal regulation, last mile delivery, optimization of routes and delivery schemes, information support, technological innovations, cluster routing, etc. In the developed mathematical model a minimum of total costs of forming loading units and freight shipments was defined as the criterion of optimality of organizing delivery by motor transport. The authors propose the creation of logistics clusters allowing the integration of urban transport flows and global supply chains.

• Journal of Pharmaceutical Investigation
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• v.40 no.spc
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• pp.45-61
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• 2010

Polymeric based nanomedicines have been developed for diagnosing, treating, and preventing diseases in human body. The nanosized drug delivery systems having various structures such as micelles, nanogels, drug-conjugates, and polyplex were investigated for a great goal in pharmaceutics: increasing therapeutic efficacy for diseases and decreasing drug toxicity for normal tissues. The functional polymers used for constituting these drug delivery systems should have several favorable properties such as stimuli-responsibility and biodegrdability for controlled drug release, and solublization capacity for programmed drug encapsulation. This review discusses recent developments and trends of functional polymers (e.g., pH-sensitive polymers, biodegradable polymers, and cationic polymers) used for nanosized drug carriers.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.107-107
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• 2013

Many nanomaterials are being harnessed as critical components in various systems for biomedical applications including diagnosis, imaging, and drug delivery. Those systems necessitate biocompatibility and low toxcity within effective dose range while achieving enough efficacy. Even though many nanomaterials enjoy successful demonstrations in bioapplications, lack of biocompatibility and high cytotoxicity often become hurdles for practical bioapplications. On the other hand, it is important to achieve enough efficiency based on chemically well-defined systems with efforts to understand mechanism at molecular level. Here, we developvarious biocompatible nanomaterials based on simple procedure using dextran as both reducing agent and surface coating. Dextran is one of the popular biocompatible polymers that have been used for drug delivery and biosensors. Dextran coated nanomaterials showed excellent colloidal stability, flexible surface chemistry for conjugation of bioactive molecules and low cytotoxicity with successful demonstrations in various bioapplications.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.1-7
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• 2015

This research is to develop a possible process to apply k-means clustering to an efficient vehicle routing process under time varying vehicle moving speeds. Time varying vehicle moving speeds are easy to find in metropolitan area. There is a big difference between the moving time requirements of two specific delivery points. Less delivery times are necessary if a delivery vehicle moves after or before rush hours. Various vehicle moving speeds make the efficient vehicle route search process extremely difficult to find even for near optimum routes due to the changes of required time between delivery points. Delivery area division is designed to simplify this complicated VRPs due to time various vehicle speeds. Certain divided area can be grouped into few adjacent divisions to assume that no vehicle speed change in each division. The vehicle speeds moving between two delivery points within this adjacent division can be assumed to be same. This indicates that it is possible to search optimum routes based upon the distance between two points as regular traveling salesman problems. This makes the complicated search process simple to attack since few local optimum routes can be found and then connects them to make a complete route. A possible method to divide area using k-means clustering is suggested and detailed examples are given with explanations in this paper. It is clear that the results obtained using the suggested process are more reasonable than other methods. The suggested area division process can be used to generate better area division promising improved vehicle route generations.

• Journal of Communications and Networks
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• v.18 no.3
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• pp.375-386
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• 2016

Most existing studies on broadcast services in orthogonal frequency division multiplexing (OFDM) systems have focused on how to allocate the transmission power to the subcarriers. However, because a broadcasting system must guarantee quality of service to all users, the performance of the broadcast service dominantly depends on the channel state of the user who has the lowest received signal-to-noise ratio among users. To reduce the effect of the worst user on the system performance, we propose a joint delivery scheme of unicast and broadcast transmissions in OFDM systems with broadcast and unicast best-effort users. In the proposed joint delivery scheme, the BS delivers the broadcast information using both the broadcast and unicast subcarriers at the same time in order to improve the performance of the broadcast service. The object of the proposed scheme is to minimize the outage probability of the broadcast service while maximizing the sum-rate of best-effort users. For the proposed joint delivery scheme, we develop an adaptive power and subcarrier allocation algorithm under the constraint of total transmission power. This paper shows that the optimal power allocation over each subcarrier in the proposed scheme has a multi-level water filling form. Because the power allocation and the subcarrier assignment problems should be jointly solved, we develop an iterative algorithm to find the optimal solution. Numerical results show that the proposed joint delivery scheme with adaptive power and subcarrier allocation outperforms the conventional scheme in terms of the outage probability of the broadcast service and the sum-rate of best-effort users.

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.256-262
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• 2012

Hyaluronic acid(HA) hydrogels were synthesized by immersing HA microbeads in phosphate buffered saline solutions having different pH levels to assess the effect of pH on the swelling ratio of HA hydrogels for smart drug delivery systems. No beads were formed when the HA solution(below pH 9) was crosslinked with divinyl sulfone(DVS) because DVS is a basic solution. The variation regarding the size of the microbead was not significant, suggesting that the bead size is not a function of pH(10 ~ 14). However, the pore size of the microbeads decreased with increasing pH from 10 to 14, leading to the surface smoothness and dense network as a result of higher crosslinking. The swelling ratio of hydrogels increased when the pH rose from 2(acidic) to 6(neutral). Afterwards, it decreased with further increasing pH(basic). The lower swelling ratio may be due to the lack of ionization of the carboxyl groups. On the other hand, a higher swelling ratio is likely due to the increased electrostatic repulsions between negatively charged carboxyl groups on different chains. Experimental results suggested that pH-responsive HA hydrogels can be applicable to the controlled drug delivery systems.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.581-585
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• 2009

Diabetes is caused by the lack of insulin secretion or the reduction in its sensitivity. The recent treatments for diabetes do not fulfill the requirements for the maintaining of normal blood glucose level. The most frequently used treatment for type I diabetes is an insulin injection. However, the insulin injection often involves the life-threatening risk and the low compliance of patients. Accordingly, extensive studies have been done to overcome the shortcomings of the injection. A representative approach is to employ self-regulated insulin delivery systems. This report includes the principles of glucose-responsive release in the self-regulated insulin delivery systems.

• The KIPS Transactions:PartA
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• v.12A no.2 s.92
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• pp.137-144
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• 2005

Many reliable group communication algorithms were presented to satisfy predetermined message ordering properties in small or medium-scale distributed systems. However, the previous algorithms with their strong reliability properties may be unappropriate for large-scale systems. To address this issue, some epidemic-style group communication algorithms were proposed for considerably improving scalability while guaranteeing the reasonably weaker reliability property than the existing ones. The algorithms are all designed for ensuring the atomic order message delivery property. But, some distributed applications such as multimedia systems and collaborative work, may require only the weaker message ordering property, i.e., causal order delivery. This paper proposes an efficient epidemic-style group communication algorithm ensuring causal order delivery to provide the indigenous scalability of the epidemic-style approach.

• Information Systems Review
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• v.24 no.4
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• pp.1-22
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• 2022

The transition to a non-face-to-face consumer society has rapidly occurred since Covid-19. The need for a subdivided urban logistics policy centered on courier delivery, a life-friendly last-mile logistics service, has been raised. This study proposes a SNS-based method that can analyze the demand relationship by region and product, respectively. We extend the market basket network (MBN) and co-purchased product network (CPN), find product category patterns, and confirm regional differences by using delivery order data. Our results imply that SNA analysis can be effectively applied to inventory distribution or product (SKU) selection strategies in urban logistics.