• International Journal of Aeronautical and Space Sciences
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• 제8권2호
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• pp.28-36
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• 2007

A multi-objective design exploration for a three-element airfoil consisted of a slat, a main wing, and a flap was carried out. The lift curve improvement is important to design high-lift system, thus design has to be performed with considered multi-angle. The objective functions considered here are to maximize the lift coefficient at landing and near stall conditions simultaneously. Kriging surrogate model which was constructed based on several sample designs is introduced. The solution space was explored based on the maximization of Expected Improvement (EI) value corresponding to objective functions on the Krigingmodels. The improvement of the model and the exploration of the optimum can be advanced at the same time by maximizing EI value. In this study, a total of 90 sample points are evaluated using the Reynolds averaged Navier-Stokes simulation(RANS) for the construction of the Kriging model. In order to obtain the information of the design space, two data mining techniques are applied to design result. One is functional Analysis of Variance(ANOVA) which can show quantitative information and the other is Self-Organizing Map(SOM) which can show qualitative information.

• Journal of Chest Surgery
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• 제27권7호
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• pp.587-597
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• 1994

To study the recovery pattern of pulmonary function after decortication, the author performed serial pulmonary function tests using spirometry before and at lst., 3rd., 4th. week, lst., 3rd., 6th. month and 1st. year in 36 patients who underwent decortication from January 1989 to September 1991 at the Department of Thoracic and Cardiovascular Surgery, Pusan National University Hospital, Pusan, Korea. Patients were divided into 3 groups by the degree of compression of lung parenchyme. Group I was classified below 20%, Group II between 21 to 40%, Group III above 41%. Their serial changes of pulmonary function test were compared. The obtained results were as follows; 1. Maximal voluntary ventilation was recovered in 1st post perative week and even greater improvement was noted in group III in which ratio to 44 % of the preoperative value. 2. Vital capacity reached nearly to preoperative values in 3rd postoperative week and had increased much further to 26 % above the preoperative figure in group II. 3. Forced expiratory volume in 1 second returned rather slowly in 3rd-4th postoperative week and the mean VC was improved more higher in group II than the other groups following decorti cation. 4. There was an greatest improvement over all tests[MW, VC, FEV1] in 2nd decade which ratios to preoperative value were 34, 25 and 22 % respectively.

• 한국지반공학회논문집
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• 제16권2호
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• pp.115-123
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• 2000

Piezocone Penetration Test has been performed in the soft ground over the site preparation area at Inchon International Airport(IIA). With the pore pressure dissipation test results, the changes in the permeability and the coefficient of consolidation in clayey soil were checked and the differences of the undrained shear stength verified the soft ground improvement effect from vane test and piezocone test both before and after the improvement. From the results, thin sand seam was found and this caused a big difference in the coefficient of permeability and consolidation. The coefficient of consolidation was high in the upper marine deposit and relatively low in lower marine deposit. It was found that the reduction of void ratio by preloading resulted in the reduction of coefficient of consolidation after the ground improvement. In addition, there were some variations of undrained shear strength when the number of 15 or 18 was used as the coefficient of piezocone(Nkt). However, when the average value of undrained shear strength calculated using Nkt=10 was applied, the result indicated the similar average value with the result of vane test and the increasing rate of strength( Δsu/Δ$\sigma$≒0.38) also showed the similar distribution.

• 한국자동차공학회논문집
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• 제23권2호
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• pp.230-238
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• 2015

The main purpose of this paper is to suggest opportunities for reducing $CO_2$ emission in energy conversion of a vehicle, focused on auxiliary energy improvement in the automotive field. As part of worldwide efforts to curb global warming and to protect the domestic industry as trade barriers, many countries have set goals to regulate greenhouse gas emissions. As an example, new $CO_2$ emission regulation in EU was expected to go into effect strictly in 2020. Therefore, global car-makers need to establish strategic responsiveness of the regulations. This paper shows $CO_2$ economic value by using the correct interpretation of the relevant laws and regulations. The $CO_2$ value analyzed using quantitative figures leads to the possibility of auxiliary(accessories, HVAC, electric apparatus etc.) technology for improving fuel economy. As a result, this study generalizes the meaning of electric power saving for each driving mode by auxiliary energy improvement.

• 대한안전경영과학회지
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• 제21권1호
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• pp.9-16
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• 2019

Logistics companies are worrying about securing of differential competitiveness so as to be competitive companies in keen logistics market. The ground is how users are satisfied by sell-established service system to respond not only economic feasibility of logistics costs but also diversity and advancement of logistics needs. The competitiveness of logistics companies is also caused by customer satisfaction of service and only companies finding and satisfying customer needs continuously may be more competitive. For the competitiveness, it's the most important to analyze demands of current and potential customers and their pursuing value properly. Therefore, this researcher grasped PSL for online logistics service users with 5-point Likert-scale and quality-level decision method that consider the weighted value based on Kano model, measured customer's potential Demand for service through PCDI, and suggested methodology for deciding the priority of the improvement with loss function of Taguchi.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3359-3366
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• 2023

In this study, a spiking cortical model (SCM) based n-g discrimination method is proposed. The SCM-based algorithm is compared with three other methods, namely: (i) the pulse-coupled neural network (PCNN), (ii) the charge comparison, and (iii) the zero-crossing. The objective evaluation criteria used for the comparison are the FoM-value and the time consumption of discrimination. Experimental results demonstrated that our proposed method outperforms the other methods significantly with the highest FoM-value. Specifically, the proposed method exhibits a 34.81% improvement compared with the PCNN, a 50.29% improvement compared with the charge comparison, and a 110.02% improvement compared with the zero-crossing. Additionally, the proposed method features the second-fastest discrimination time, where it is 75.67% faster than the PCNN, 70.65% faster than the charge comparison and 38.4% slower than the zero-crossing. Our study also discusses the role and change pattern of each parameter of the SCM to guide the selection process. It concludes that the SCM's outstanding ability to recognize the dynamic information in the pulse signal, improved accuracy when compared to the PCNN, and better computational complexity enables the SCM to exhibit excellent n-γ discrimination performance while consuming less time.

• 한국지반환경공학회 논문집
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• 제11권10호
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• pp.5-13
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• 2010

저유동성 몰탈주입은 구조물기초의 보강이나 연약지반 개량 등에 폭넓게 쓰이고 있으며, 작업 공간이 협소한 경우도 주변여건에 크게 구속받지 않고 시공할 수 있는 등 매우 유리한 특징을 가지고 있다. 그러나 현재 저유동성 몰탈주입공법의 설계단계에서 적용할 수 있는 개량효과 및 영향 반경에 대한 예측방법과 이에 대한 검증이 이루어지지 않아 지반보강공법으로써의 다양한 적용을 위하여 이에 대한 정립이 필요하다. 본 연구에서는 매립토층에서 저유동성 몰탈주입 후 현장시험을 실시하여 주입에 의한 지반개량효과를 확인하고, 이를 기존의 제안된 개량효과에 대한 이론식으로 계산된 값과 비교함으로써 이론식의 적용성을 평가하고자 하였다. 연구결과, 저유동성 몰탈주입에 의해 개량효과가 매우 우수함을 확인할 수 있었으며, 이를 기존의 이론식과 비교한 결과 서로 유사한 결과를 나타내어 연구대상 현장과 유사한 느슨한 사질토의 경우 기존의 이론식은 적용성이 양호한 것으로 판단된다.

• 전기전자학회논문지
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• 제13권2호
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• pp.248-252
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• 2009

In this paper, analysis of a noise factor and an effective power strategy for the OLED dc-dc converter are described. One of the main reasons that one may not design the OLED power for dc-dc converter is that OLED's panel noise is composed of FFN(Frame Frequency Noise) and LFN(Line Frequency Noise). Into the bargain, FFN is caused by both the dc-dc (circuit) and driving circuit. It is hard to get rid of FFN, baeause FFN has very little results value for our ears. LFN is adjusted by analog compensation value. Actually, that is more important problem than FFN. It is known that voltage divider for OLED's mode variation is not good for compact power design. In the end, a circuit design for understanding OLED's noise and a novel muti-channel dc-dc converter were presented.

• 벤처창업연구
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• 제7권1호
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• pp.177-187
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• 2012

설계VE를 수행함에 있어서 아이디어 발상 단계의 한계사항을 지적하고, TRIZ와 적절한 연계를 통하여 보다 효과적인 방안을 모색하고자 한다. 창의적이고 체계적인 접근과 효율적인 아이디어 발상을 통하여, 보다 최적에 가까운 대안을 도출할 수 있는 설계VE/TRIZ 의 추진절차와 단계별 업무내용을 제시하였다.

• 품질경영학회지
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• 제37권3호
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• pp.123-139
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• 2009

This study examines the relative efficiency of 34 local public medical centers in Korea. In order to concretely grasp the causes of inefficiency and suggest improvement solutions, the desirable set point was established based on the actual value which needs to be improved. As a result of analysis, we determined that output must be increased while input is held constant in order to improve effectiveness through the actual value and set point. Efficiency cannot be achieved if input is augmented solely to increase output. Also, to increase output, the medical centers need to improve their quality without increasing any input for customer visits and hospitalizations. Further, in order to strategically promote effectiveness and efficiency of local public medical centers, these medical centers must focus on input resource and patient interchange through the mutual cooperation with local private hospitals and university medical centers.