• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5A
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• pp.447-451
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• 2010

We propose an advanced BMPA (balanced multimedia packet allocation) scheme. The proposed scheme considers the optimal resource allocation problem in OFDMA system. When NRT (non-real time), RT (real time), multicast packets arrive at the same time in OFDMA system, the advanced BMPA chooses the best sub-carrier as a multicast channel for multicast packets, gives more weight to RT packets and multicast packets than NRT packets and allocates sub-carriers according to the total weight sum of packets in each user. With simulation results, this paper shows that the advanced BMPA scheme ensures QoS (long-term system throughput and multimedia packet delay) in heterogeneous traffic compared with multicast MU-WF (multi-user water-filling) and BMPA schemes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.6
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• pp.414-423
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• 2014

The number and size of resource constituting the web page has been increasing steadily, and this circumstance leads to rapidly falling quality of web service in mobile network that offer relatively higher delay. Moreover, Improving the quality of a web services protocol is difficult to provide network function because the current network architecture has closed structure. In this paper, we suggest schemes to enhance web performance in mobile network, which are Check Coded DOM scheme and Functional JavaScript Transmission scheme, and then try to seek idea which can be provided suggested schemes as a network function using NFV(Network Function Virtualization). For the performance evaluation and analysis about the suggested schemes, we perform network simulation using SMPL library. We confirm that suggested schemes offer better performance in term of page loading time, the number of message and the amount of traffic in the network than HTTP Protocol.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.5
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• pp.102-112
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• 2012

The vast stores of biomass available in the worldwide have the potential to displace significant amounts of fuels that are currently derived from petroleum sources. Fast pyrolysis of biomass is one of possible paths by which we can convert biomass to higher value products. The wood pyrolysis oil (WPO), also known as the bio crude oil (BCO), have been regarded as an alternative fuel for petroleum fuels to be used in diesel engine. However, the use of BCO in a diesel engine requires modifications due to low energy density, high water contents, low acidity, and high viscosity of the BCO. One of the easiest way to adopt BCO to diesel engine without modifications is emulsification of BCO with diesel and bio diesel. In this study, a diesel engine operated with diesel, bio diesel (BD), BCO/diesel, BCO/bio diesel emulsions was experimentally investigated. Performance and gaseous & particle emission characteristics of a diesel engine fuelled by BCO emulsions were examined. Results showed that stable engine operation was possible with emulsions and engine output power was comparable to diesel and bio diesel operation. However, in case of BCO/diesel emulsion operation, THC & CO emissions were increased due to the increased ignition delay and poor spray atomization and NOx & Soot were decreased due to the water and oxygen in the fuel. Long term validation of adopting BCO in diesel engine is still needed because the oil is acid, with consequent problems of corrosion and clogging especially in the injection system.

• Archives of Plastic Surgery
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• v.34 no.3
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• pp.336-341
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• 2007

Purpose: The most accepted method for the reanimation of a paralyzed face is the two-stage method that combines cross-face nerve grafting with free-muscle transfer. Although the results of reconstruction with this method are satisfactory, there is an excessive delay between the stages, which prolongs the period of rehabilitation. In order to overcome this drawback, a one- stage, neurovascular free-flap reconstruction method using free neurovascular muscle flaps is introduced. Methods: From 1994 to 2004, 35 patients with longstanding facial palsy were treated. Fifteen patients underwent the single-stage reconstruction with the latissimus dorsi muscle, and 20 patients underwent the two-stage reconstruction method with the gracilis muscle. We compared the long-term results of the two methods of reconstruction. The mean follow-up period was 28.7 months for one-stage reconstruction, and 35.2 months for the two-stage, respectively. Results: In the patient group of the single stage reconstruction, both mouth corner excursion and animation grade were markedly improved at the final postoperative visit. Moreover, the first muscle contraction occurred earlier in this group, than in the two-stage reconstruction group. However, four patients in the single stage group never achieved a first muscle contraction or mouth corner excursion. Conclusion: Facial palsy is a very challenging condition for cosmetic surgeons to deal with. Traditional methods for treatment of chronic facial palsy use a two-stage muscle flap which is time-consuming and burdensome to patients, many of whom are averse to waiting 8 to 12 months to complete the two stages. The one-stage reconstruction method described herein uses a latissimus dorsi free-flap and has demonstrated consistent positive outcomes in clinical assessments.

• Archives of Plastic Surgery
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• v.39 no.1
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• pp.42-45
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• 2012

Background : Conservative techniques designed to block or delay the aging process have been utilized in various ways for many years. However, their effects can be relatively minimal and short-term in most cases compared to surgery. The objective of this study was to evaluate the efficacy and safety of gold thread implantation for the treatment of periorbital wrinkles. Methods : A total of 78 consecutive patients who showed mild to severe periorbital wrinkles were deemed appropriate candidates, including 69 women and 9 men ranging from 31 to 59 years (mean, 47 years). Six gold threads about 4 cm in length were inserted subdermally in each patient at intervals of about 0.5 cm. Follow-up assessments were performed 1, 4, and 12 weeks after the procedure. The efficacy was rated by the physician using the Wrinkle Severity Rating Scale and patients who made global assessments of changes in periorbital wrinkles using the Visual Analog Scale. Adverse events were monitored throughout the course of the study. Results : The patients showed significant improvements after the procedure. There were minor complications such as foreign body sensation in the eye (2.63%) and eye pain (1.32%) that improved spontaneously without any specific treatments. Conclusions : Subdermal implantation of gold thread improves the appearance of periorbital wrinkles and does not appear to have serious side effects. Insertion of gold thread may be an effective and safe method for facial rejuvenation.

• Journal of KIISE:Information Networking
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• v.32 no.6
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• pp.676-686
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• 2005

The Internet users as well as network providers are eager to have different qualities of service among users beyond the best-effort. In this paper, we propose a scheduling algorithm that provides a differentiated service in the granularity of user sessions. The proposed algorithm is a Hierarchical Deficit Round-Robin (H-DRR) algorithm that is an extension of an existing DRR algorithm. A main advantage is that H-DRR provides service differentiation for throughput-intensive applications such as FTP as well as delay-sensitive applications such as telnet or VoIP without distinguishing the types of applications. The most importance in providing a service differentiation in term of network providers is to have controllability and predictability. We show that H-DRR is superior to DRR in terms of controllability and predictability through both mathematical analysis and simulation experiments. Nevertheless, H-DRR requires O(1) complexity for implementation.

• Journal of Information Management
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• v.18 no.4
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• pp.98-117
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• 1985

At the present time, the role and importance of information retrieval has greatly increased for two main reasons: the coverage of the searchable collections is now extensive and collection size may exceed several million documents; further more, the search results can now be obtained more or less instantaneously using online procedures and computer terminal devices that provide interaction and communication between system and users. The large collection size make it plausible to the users that relevant information will in fact be retrieved as a result of a search operation, and the probability of obtaining the search output without delay creates a substantial user demand for the retrieval services.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4A
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• pp.377-385
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• 2010

In this paper, we propose a SInk-initiated geographic Multicast (SIM) protocol to reduce frequent location updates from mobile sinks to a source and to achieve fast multicast tree construction and data delivery. The proposed protocol allows sinks to construct their own data delivery paths to a source node and a multicast tree to be atomically constructed by merging the paths. Then, the source forwards data to the destinations down the multicast tree. This paper also propose a round-based virtual infrastructure with a radial shape for increasing the merging probability of data delivery paths and reducing reconstruction ratio of the multicast tree due to mobility of sinks. Simulation results show that the proposed protocol is superior to previous SOurce-initiated geographic Multicast (SOM) protocols in term of average data delivery delay and average energy consumption.

• Korean Journal of Applied Biomechanics
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• v.17 no.1
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• pp.111-119
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• 2007

The purpose of this study was to investigate muscle activity and gait pattern in lower limb depending on the outsole of heel rockers. Fifteen healthy men volunteered for this experiment. Each subject performed totally three trails with two pairs of different heel rocker shoes and a pair of normal running shoes at speed of 1.33m/s for 1 minute during walking on a treadmill. Kinematic data gathered in 100Hz was recorded and analyzed by using the 3D motion capture system to measure the trunk tilt and joint angle of the right lower limb. And the lower extremity muscle activities were simultaneously recorded in 1000Hz and assessed by using EMG. The statistical analysis was the one-way ANOVA with the repeated measures to compare among the three kinds of shoes. The level of statistical significance for all tests was 0.05. Joint angle of lower limb was showed statistically significant different in MST(hip joint), LHS(ankle joint), and RTO(knee and ankle joint). Muscle activity of rectus femoris and biceps femoris was statistically increased in both heel rocker shoes during gait cycle on treadmill. The maximum peak time of tibialis anterior in the negative heel rocker showed the delay of approximately 23.8%time than normal shoes. Gait pattern variability of the negative heel rocker was increased in the first half of the stance phase and the variability of the positive heel rocker was increased in the terminal stance phase. In Conclusion, stability was decreased in between joints of lower limb on positive heel rocker than negative heel rocker. This study found that there were different joint angle, muscle activity, gait pattern and coordinate system of the lower limb in each kind of shoes. These unstability affected the lower extremity and the whole body. A further study has to be continued with study of rehabilitation and exercise for a long-term.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.61
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• pp.273-302
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• 2014

Project finance ("PF") is a method of raising long-term debt financing based on lending against the cash flow generated by the project alone. Project finance is a nonrecourse or limited recourse financing structure against the sponsors(or the investors). The debt terms in a project finance are not based on the creditor's credit support or on the value of the assets of the project. Lenders rely on the future cash flow to be generated by the project for debt repayment and interest, rather than the value of the project or the credit ratings of the sponsors. The non-recourse or limited recourse financing usually prompt potential project finance lenders to assess carefully all possible risks that might arise in a project to ensure that those risks are mitigated and controlled. In this respect, project finance is a opposite financing method of corporate finance. Project finance has rapidly grown over the last 20 years due to the worldwide process of privatization of public sector and development of natural resources. Global project finance volume reached the record USD 406.5 billion in 2011. In 2012, however, Global project finance volume dropped 6% to USD 382.3 billion. Infrastructure overtook Energy to lead all sectors with USD 113.6 billion. It is generally recognized that there are more and higher risks in project finance compared with corporate finance. Project finance is exposed to commercial risks as well as political risks. The main commercial risks are completion risks, environmental risks, operating risks, input supply risks, revenue risks, etc, and the main political risks are currency convertibility and transfer risks, expropriation risks, war and civil disturbance risks, risks of breach of government concession agreement, etc. Completion risks include permits risks, risks relating to the EPC Contractor, construction cost overrun, delay in completion, inadequate performance on completion, etc.