• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.4
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• pp.826-839
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• 2014

Fire is a continuous threat to FPSO topside modules as large amounts of oil and gas are passing through the modules. As a conventional measure to mitigate structural failure under fire, passive fire protection (PFP) coatings are widely used on main structural members. However, an excessive use of PFP coatings can cause considerable cost for material purchase, installation, inspection and maintenance. Long installation time can be a risk since the work should be done nearly at the last fabrication stage. Thus, the minimal use of PFP can be beneficial to the reduction of construction cost and the avoidance of schedule delay. This paper presents a few case studies on how different applications of PFP have influence on collapse time of a FPSO module structure. A series of heat analysis and thermal elasto-plastic FE analysis are performed for different PFP coatings and the resultant collapse time and the amount of PFP coatings are compared with each other.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.3
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• pp.325-334
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• 2009

Generally, functional design of FPSO has been done by the engineering firm designated by ship owner. Main equipment such as topside facility is imported from abroad. But sometimes, OFE (Owner Furnished Equipment) does not satisfy the PND (Product Need Date) of each production stage because the delivery date of OFE is not scheduled to satisfy the PND. And sometimes many loose items and equipment are complex from engineering which does not consider pre-outfitting. Main objective of this study is process improvements by maximizing pre-outfitting rate in the stage of equipping STP (Submerged Turret Production), one of main equipment on FPSO. In this study, we analyzed the factors which obstructed pre-equipping STP using the past records of FPSO projects.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.3-9
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• 2015

We investigate rate scheduling and power allocation problem for a delay constrained CDMA systems. Specifically, we determine an energy efficient scheduling policy, while each user maintains the short term (n time slots) average throughput. We consider a multirate CDMA system where multirate is achieved by multiple codes. Each code can be interpreted as a virtual user. The aim is to schedule the virtual users into each time slot, such that the sum of transmit energy in n time slots is minimized. We then show that the total energy minimization problem can be solved by a shortest path algorithm. We compare the performance of the optimum scheduling with that of TDMA-type scheduling.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.384-392
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• 2015

This paper presents an economic assessment of large-scale Li-ion battery energy storage systems applied to Korean power system. There are many applications of the battery energy storage systems (BESSs) and they can provide various benefits to power systems. We consider BESSs to the energy time-shift application to Korean power system and evaluate the benefits from the application of BESS in the social perspective. The mixed integer programming (MIP) algorithm is used to resolve the optimal operation schedule of the BESS. The social benefits can include the savings of the fuel cost from generating units, deferral effects of the generation capacity, delay of transmission and distribution infra construction, and incremental CO2 emission cost impacts, etc. The economic evaluation of the BESS is separately applied into Korean power systems of the Main-land and Jeju island to reflect the differences of the load and generation patterns.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.6
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• pp.844-852
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• 2017

Since guided weapon is high-cost and one-shot device which is non-reusable, it requires a lot of resources to prove required accuracy as a part of reliability demonstration. Once a test for proving accuracy rate of guided missile fails, it causes an additional cost and delay of schedule. This study introduces an equation for proper sample size and plan for guided-missile accuracy rate test in order to minimize the risk of test failure. Proper sample size for the test is derived by considering the reliability growth. Furthermore, each task for accuracy rate test is defined according to the development step. Therefore, this study can contribute to reduce sample size for accuracy rate test in order to meet the reliability requirement and assure transparency in the test process.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.216-217
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• 2015

Duty-cycling could efficiently prolong the life time of Wireless Sensor Networks (WSNs) by let nodes be in dormant state most of the time, and only wake up (for sending or receiving) for a very short period. Flooding is one critical operation of WSNs. Many studies have been studied to improve the delay and/or energy efficiency of flooding. In this paper, we propose a novel time slot design, and the switching decision that reduce energy consumption for the schedule-based flooding tree. Each node, if failed to receive from its parent, will look for other candidate, among its siblings to overhear the flooding packet. By accurately collect information from other siblings, each node can make the best as possible switching decision; therefore the energy efficiency of the network is improved.

• Journal of mucopolysaccharidosis and rare diseases
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• v.4 no.2
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• pp.42-44
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• 2018

Prader-Willi syndrome (PWS) is a multisystemic complex disorder characterized by hyperphagia and impaired satiety which lead to severe and early obesity. In infancy, hypotonia and poor suck are main problems, and a child goes through Failure-to-thrive. During childhood, clinical manifestations change to food seeking as well as excessive weight gain, short stature, developmental delay, cognitive disability and behavioral problems. Also, growth hormone insufficiency is frequent. Most patients receive the recombinant growth hormone (rGH) therapy that provides improvement in growth, body composition, and physical attributes. The clinical care guideline for rGH therapy in PWS had been noticed in 2013. The rGH therapy helps in body fat, lean body mass, height SDS and head circumference. Also, the rGH therapy helps motor function, psychomotor development and cognition and behavioral issues.In Samsung medical center, there are clinical care guidelines for rGH therapy in PWS and an useful application for the patients. 'Living with PWS', the name of an moblie application for PWS patients, was introduced in the lecture. The application revised to version 2. It was made more convenient to users than in version 1. It helps caregivers to schedule the rGH therapy and to monitor height and weight.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.2
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• pp.9-17
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• 2019

In order to deal with high uncertainty and variability in emergency medical centers, many researchers have developed various models for their operational planning and scheduling. However, most of the models just provide static plans without any risk measures as their results, and thus the users often lose the opportunity to analyze how much risk the patients have, whether the plan is still implementable or how the plan should be changed when an unexpected event happens. In this study, we construct a simulation model combined with a risk-based planning and scheduling module designed by Simio LLC. In addition to static schedules, it provides possibility of treatment delay for each patient as a risk measure, and updates the schedule to avoid the risk when it is needed. By using the simulation model, the users can experiment various scenarios in operations quickly, and also can make a decision not based on their past experience or intuition but based on scientific estimation of risks even in urgent situations. An example of such an operational decision making process is demonstrated for a real mid-size emergency medical center located in Seoul, Republic of Korea. The model is designed for temporal short-term planning especially, but it can be expanded for long-term planning also with some appropriate adjustments.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.5
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• pp.314-321
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• 2021

In the existing whole ship analysis, topside was modeled as mass element. However recently, the topside is modeled as beam element due to the owner's requirement to improve the maturity of the whole ship FE model. To follow the owner'srequirement, detailed information for topside drawing and modeling, which may delay analysis schedule, is needed. However, it is hard to respond effectively to this matter due to the lack of study on the topside from the hull perspective. Therefore in this study, the effect of the topside on the hull is investigated when the topside is modeled as a mass element or beam element respectively. In addition, the interface modeling method is analyzed to verify modeling method used in the existing whole ship analysis. The results indicate that the interface and topside modeling method used in existing whole ship analysis are appropriate. This conclusion will be the technical basis for responding to owner's requirement about the topside modeling method.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.327-333
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• 2022

Wireless Sensor Networks (WSNs) plays an important role in our everyday life. WSN is distributed in all the places. Nowadays WSN devices are developing our world as smart and easy to access and user-friendly. The sensor is connected to all the resources based on the uses of devices and the environment [1]. In WSN, Quality of Service is based on time synchronization and scheduling. Scheduling is important in WSN. The schedule is based on time synchronization. Min-Max data size scheduling is used in this proposed work. It is used to reduce the Delay & Energy. In this proposed work, Two-hop neighboring node is used to reduce energy consumption. Data Scheduling is used to identify the shortest path and transmit the data based on weightage. The data size is identified by three size of measurement Min, Max and Medium. The data transmission is based on time, energy, delivery, etc., the data are sent through the first level shortest path, then the data size medium, the second level shortest path is used to send the data, then the data size is small, it should be sent through the third level shortest path.