• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.79-81
• /
• 2004

본 논문에서는 전력시스템의 정적 안전도수준(Steady-state Security Level)을 평가할 수 있는 안전도 지수를 전력시스템의 영향을 반영하는 가중치를 고려하여 보다 개선된 안전도 지수를 제안한다. 먼저, N-1선로사고를 가정하여 각 선로가 계통에 미치는 영향과 각 선로의 사고로 인해 모선 전압의 변동량을 분석하여 각각 안전도 지수들의 가중치를 산정한다. 이때, 가중치의 표준화를 위해 분포도(Distribution Chart)를 활용한다. 가중치가 적용된 안전도 지수는 이를 고려하지 않은 안전도 지수보다 더욱 계통상황을 잘 반영할 것이며, 전력계통 운영 상태를 나타내는 중요한 지표로서 활용될 수 있을 것이다.

• International Journal of Knowledge Content Development & Technology
• /
• v.7 no.2
• /
• pp.5-20
• /
• 2017

The notion of object oriented analysis and design in software engineering has many rewards that aid the programmer to have an understanding of and improve the program efficaciously. Object oriented metrics helps rather a lot to a programmer or developer to comprehend and unravel the thing-oriented trouble readily and exactly. Object oriented metrics helps in examining the usefulness of object oriented applied sciences or in simple phrases Object-oriented metrics depict characteristics of object-oriented programming. The intention of this paper is to have an understanding of concerning the UML, Object oriented evaluation and design and the way it plays in UML.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.5
• /
• pp.133-144
• /
• 2003

Horizontal consolidation characteristics of Busan marine clay were investigated by computing coefficient of horizontal consolidation from Piezocone data and comparing their results with those of standard consolidation test. It is well known that current prediction models of $c_h$ for high plastic soils have large uncertainties, and show a great difference between the predicted and the measured values. However, the spherical models and expanding cavity theory of Torstensson(1977), and Burns & Mayne(1998) based on modified Cam-Clay model with critical limit state concepts have relative reliability in estimating $c_h$ and good applicability in highly plasticity soils. In this paper, a normalization technique was used to evaluate $c_h$ using the Burns and Mayne's method based on the dissipation test, and their normalized consolidation curves give 0.015 of time factor($T_{50}$) when 50% degree of consolidation is completed. Comparison study using Piezocone data obtained at other similar ground site shows 1.5 times less systematicality than that of standard consolidation test, which indicates considerable approximation with the measured values because standard consolidation test gives the difference of three to few times compared with the measured values. In addition, design chart for estimating $c_h$ based on the chart from Robertson et al.(1992) and using the other method of the direct prediction from the of dissipation test was newly proposed. It is judged that new proposed chart is very applicable to Korean marine soils, especially in very high plastic soils.

• Journal of the Society of Naval Architects of Korea
• /
• v.56 no.6
• /
• pp.480-487
• /
• 2019

Ship route planning is to find a route to minimize voyage time and/or fuel consumption in a given sea state. Unlike previous studies, this study proposes an optimization method for the route planning to avoid the grounding risk near the coast. The route waypoints were searched using A^* algorithm, and the route simplification was performed to remove redundant waypoints using Douglas-Peucker algorithm. The optimization was performed to minimize fuel consumption by setting the optimization design parameters to the engine rpm. The sea state factors such as wind, wave, and current are also considered for route planning. We propose the constraint to avoid ground risk by using under keel clearance obtained from electoronic navigational chart. The proposed method was applied to find the optimal route between Mokpo and Jeju. The result showed that the proposed method suggests the optimal route that minimizes fuel consumption.

• Journal of Oriental Neuropsychiatry
• /
• v.22 no.4
• /
• pp.87-100
• /
• 2011

Objectives : This study aims to evaluate the relationship between HRV indices and scores of emotional questionnaires and to find out the effective way to assess patients emotional and physical condition. Methods : We selected 144 patients who had both HRV data and BDI, STAI and STAXI scores on the chart among outpatients from July 2006 to December 2010. The relationship between the scores rated from the questionnaires and HRV indices are analyzed. And the HRV indices of patients included in the top 30 percent group and the bottom 30% group are compared. Results : 1. There were no significant correlations between HRV indices and scores of BDI, STAI and trait anger of STAXI. 2. SDNN and TP of HRV significantly decreased with higher state anger scores of STAXI. The top 30 percent group of state anger had lower SDNN, TP, LF, HF and HRV-index and higher pNN50 than the bottom 30 percent group. 3. RMSSD of HRV significantly decreased with higher anger-in scores of STAXI. The top 30 percent group of anger-in had lower RMSSD than the bottom 30 percent group. Conclusions : HRV can be used to evaluate emotional and physical changes related to state anger and inappropriate anger expression.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.7 no.2
• /
• pp.117-124
• /
• 2013

Objective : To investigate the actual driving state of the stroke patients who had assessed CPAD. Methods : We conducted a follow-up survey with 48 stroke patients who had assessed CPAD. First, we reviewed the medical chart and then carried out the telephone survey. Results : Of the 48 subjects, 12 were driving and 36 were not driving. Current drivers' CPAD score, it was 54.13, was higher than non-drivers' CPAD score(p<0.05). Those who passed the CPAD were driving more than who failed(OR=8.3, 95%CI=1.931-35.558). Conclusion : The pass group of CPAD have higher chance of driving than fail group and have lower chance of car accidence than fail group. Thus we can apply the CPAD for driving cognitive evaluation tests.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.3
• /
• pp.299-305
• /
• 2015

Global environmental concerns and the ever increasing need of energy, coupled with steady progress in renewable energy technologies, are opening up new opportunities for utilization of renewable energy resources. Distributed electricity generation is a suitable option for sustainable development thanks to the load management benefits and the opportunity to provide electricity to remote areas. Solar energy being easy to harness, non-polluting and never ending is one of the best renewable energy sources for electricity generation in present and future time. Due to the random and intermittent nature of solar source, PV plants require the adoption of an energy storage and management system to compensate fluctuations and to meet the energy demand during night hours. This paper presents an efficient, economic and technical model for the design of a MPPT based grid connected PV with battery storage and management system. This system satisfies the energy demand through the PV based battery energy storage system. The aim is to present PV-BES system design and management strategy to maximize the system performance and economic profitability. PV-BES (photovoltaic based battery energy storage) system is operated in different modes to verify the system feasibility. In case of excess energy (mode 1), Li-ion batteries are charged using CC-CV mechanism effectively controlled by fuzzy logic based PID control system whereas during the time of insufficient power from PV system (mode 2), batteries are used as backup to compensate the power shortage at load and likewise other modes for different scenarios. This operational mode change in PV-BES system is implemented by State flow chart technique based on SOC, DC bus voltages and solar Irradiance. Performance of the proposed PV-BES system is verified by some simulations study. Simulation results showed that proposed system can overcome the disturbance of external environmental changes, and controls the energy flow in efficient and economical way.

• Korean Journal of Head & Neck Oncology
• /
• v.33 no.2
• /
• pp.17-22
• /
• 2017

Background and Objectives: Voice change after thyroidectomy may develop without injury of recurrent laryngeal nerve. Psychogenic or emotional factors related to voice change after thyroidectomy has been rarely studied. In this study, we sought to analyze the impact of anxiety on early state of post-thyroidectomy voice change. Materials and Methods: We made a retrospective chart review of 36 patients who underwent thyroidectomy for papillary thyroid carcinoma and voice exam before surgery, 2 weeks after and 1 month after surgery. All patients included in the study answered a questionnaire for State-Trait Anxiety Inventory ; STAI-KYZ (form Korean YZ). Clinico-pathologic factors and parameters of voice analysis were reviewed to analyze correlation to the anxiety index. Results: No differences were identified between clinicopathologic factors and preoperative parameters of voice analysis between patients with higher and lower level of anxiety. Noise to harmonic ratio (NHR) was higher in those patients with higher level of anxiety, 2 weeks after surgery (p=0.043). However, none of the parameters showed any difference 1 month later. Conclusion: With limited number of patients and short period of follow up, significant impact of preoperative anxiety on postoperative voice change after thyroidectomy could not be identified in this preliminary study.

• Archives of Plastic Surgery
• /
• v.49 no.2
• /
• pp.184-194
• /
• 2022

The face and the external nose define an individual's physical appearance. Nasal deformities can cause facial disfigurement along with unwanted psychological repercussions. Nasal deformities range in severity, with the most severe cases being indications for a rhinectomy, due to the complexity of the nasal defect. According to published literature, there is no consensus among otolaryngologists and plastic surgeons on which technique or flap use is preferred in terms of complications, aesthetic outcome, or patient satisfaction. The goal of this study is to provide a comprehensive analysis of published studies on nasal reconstruction following rhinectomy. Using the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines for writing systematic reviews, a systematic review was conducted. Four databases were searched using a search strategy. These articles were then imported into the COVIDENCE software and went screening and thorough article review. After screening 2,237 articles, 23 studies were then extracted for data collection analysis. We collected data from 12 case series, 4 case studies, 1 prospective case series, and 4 retrospective chart review studies. The most commonly reported flaps were forehead flaps, superior extended nasal myocutaneous island, forearm free flaps, anterolateral thigh (ALT) free flap, medial femoral condyle free flap (n = 8), and zygomaticus implants (n = 6), and retained nasal prosthesis. Although not specifically indicated by a certain number, the most common indication for the rhinectomy was malignancy, followed by traumas, postsurgical complications, radionecrosis, and congenital nasal malformations.

• Journal of Oriental Neuropsychiatry
• /
• v.34 no.3
• /
• pp.151-161
• /
• 2023

Objectives: To examine effect of Korean medical treatment on patients with insomnia and correlations among changes in psychological scales before and after treatment. Methods: Medical records of 38 patients diagnosed with insomnia based on DSM-V who received Korean medical treatment (herbal-medication, acupuncture, Korean psychotherapy) for at least 8 weeks were retrospectively reviewed. Psychological scales including Insomnia Severity Scale (ISI), Beck Depression Inventory-II (BDI-II), State-Trait Anxiety Inventory (STAI), Beck Anxiety Inventory (BAI), and State-Trait Anger Expression Inventory (STAXI) were measured every four weeks and analyzed. Results: After eight weeks of treatment, ISI, BDI-II, BAI, STAI-X-1/2, and STAXI-S/T showed statistically significant decreases. Psychological scale pairs that showed a statistically significant correlation were ISI and BDI-IIㆍSTAI-X-1ㆍSTAI-X-2ㆍTA, BDI-II and BAIㆍSTAI-X-1ㆍSTAI-X-2ㆍAX-I, BAI and STAI-X-1ㆍSTAI-X-2ㆍSAㆍTA, STAI-X-1 and STAI-X-2, SA and TA, and TA and AX-I. In women, the improvement of AX-C was high. The improvement in AX-I score was significant when the disease duration was more than one year. A lower pretreatment BAI value predicted a greater decrease in ISI score after treatment. Conclusions: Korean medical treatment including herbal medicine, acupuncture, and Korean psychotherapy was effective in improving insomnia symptoms and accompanying symptoms such as depression, anxiety, and anger. In the future, more in-depth follow-up research is needed on the mechanisms by which various psychological problems (depression, anxiety, anger, etc) cause and worsen insomnia and the psychological symptoms secondary to insomnia.