• 전자공학회논문지CI
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• 제44권2호
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• pp.11-18
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• 2007

신경회로망의 학습에 널리 사용되고 있는 오차역전파 알고리즘은 최급하강법을 기초로 하고 있기 때문에 초기값에 따라서는 극소값에 떨어지거나, 신경회로망을 학습시킬 때 중간층 유닛수를 얼마로 설정하는 등의 문제점이 있다. 따라서 이러한 문제점을 해결하기 위하여, 본 논문에서는 3비트 패리티 판별을 위하여 신경회로망의 학습에 교차법, 돌연변이법에 새로운 기법을 도입한 개량형 유전적 알고리즘을 제안한다. 본 논문에서는 세대차이, 중간층 유닛수의 차이, 집단의 개체수의 차이에 대하여 실험을 실시하여, 본 방식이 학습 속도의 면에서 유효하다는 것을 나타낸다.

• Geomechanics and Engineering
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• 제30권4호
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• pp.363-372
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• 2022

One of the most frequent issues in tunnel excavation is the collapse of rock blocks and the dropping of rock fragments from the tunnel face. The tunnel face can be reinforced using a number of techniques. One of the most popular and affordable solutions is the use of face longitudinal dowels, which has benefits including high strength, flexibility, and ease of cutting. In order to examine the reinforced face, this work shows the longitudinal deformation profile and ground response curve for a tunnel face. This approach is based on assumptions made during the analysis phase of problem solving. By knowing the tunnel face response and dowel behavior, the interaction of two elements can be solved. The rock element equation derived from the rock bolt method is combined with the dowel differential equation to solve the reinforced ground response curve (GRC). With a straightforward and accurate analytical equation, the new differential equation produces the reinforced displacement of the tunnel face at each stage of excavation. With simple equations and a less involved computational process, this approach offers quick and accurate solutions. The FLAC3D simulation has been compared with the suggested analytical approach. A logical error is apparent from the discrepancies between the two solutions. Each component of the equation's effect has also been described.

• 한국표면공학회지
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• 제50권5호
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• pp.411-420
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• 2017

In this paper, two methods of making the Pd-added $SnO_2$ ($Pd-SnO_2$) powder with pure tetragonal phase by the hydrazine method were suggested and compared in terms of crystal structure, surface morphology, and alcohol gas response. One of the addition methods is to use $PdCl_2$ as a Pd source, the other is to use Pd-based organic with oleylamine (OAM). When Pd concentration was increased from 0 to 5 wt%, the average grain size of $Pd-SnO_2$ made with Pd-OAM were decreased from 32 to 12 nm. In the case of using with $PdCl_2$, grain size of the $PdCl_2$ fell to less than 10 nm. However, agglomerated and extruded surface morphology was observed for the films with Pd addition over 4 wt%. The crack-free $Pd-SnO_2$ thick films were able to successfully fill the $30{\mu}m$ gap of patterned Pt electrodes by optimized ink dropping method. Also, the 2 wt% $Pd-SnO_2$ thick film made with PdCl2 showed gas responses ($R_{air}/R_{gas}$) of 3.7, 5.7 and 9.0 at alcohol concentrations of 10, 50 and 100 ppm, respectively. On the other hand, the prepared 3 wt% $Pd-SnO_2$ thick film with Pd-OAM exhibited very excellent responses of 3.4, 6.8 and 12.2 at the equivalent measurement conditions, respectively. The 3 wt% $Pd-SnO_2$ thick film with Pd-OAM has a specific surface area of $31.39m^2/g$.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권3호
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• pp.838-856
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• 2014

Enhanced network speed and the appearance of various applications have recently resulted in the rapid increase of Internet users and the explosive growth of network traffic. Under this circumstance, Internet users are eager to receive reliable and Quality of Service (QoS)-guaranteed services. To provide reliable network services, network managers need to perform control measures involving dropping or blocking each traffic type. To manage a traffic type, it is necessary to rapidly measure and correctly analyze Internet traffic as well as classify network traffic according to applications. Such traffic classification result provides basic information for ensuring service-specific QoS. Several traffic classification methodologies have been introduced; however, there has been no favorable method in achieving optimal performance in terms of accuracy, completeness, and applicability in a real network environment. In this paper, we propose a method to classify Internet traffic as the first step to provide stable network services. We integrate the existing methodologies to compensate their weaknesses and to improve the overall accuracy and completeness of the classification. We prioritize the existing methodologies, which complement each other, in our integrated classification system.

• Archives of Plastic Surgery
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• 제43권1호
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• pp.46-52
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• 2016

Background The loss of nasal tip support is caused by many factors and eventually results in the collapse and eventual dropping of the nasal tip. This reduces the nasolabial (NL) angle and negatively affects respiratory functions and one's appearance. Methods The aim of this retrospective study, which was conducted on 52 patients, was to present and popularize a simple and effective method for the reconstruction of a weakened columella by inserting an autologous ear cartilage graft using a sublabial approach. Results Of all the patients, three patients experienced transplant rejection. The period of follow-up observation was one to five years (mean, 27 months). The results were objectively evaluated by measuring the NL angle in standardized photos before and after the procedure at different time intervals over the follow-up period. We observed a significant increase of the NL angle (mean, $20^{\circ}$), and found these results to be durable over the long term. Of the 52 patients included in this study observed patients, three were dissatisfied (due to immediate infection and shifting of the strut), 28 were satisfied, and 21 were very satisfied. Conclusions The surgical method described here is simple and can be learned quickly. It has very good results with few complications, and is our method of choice for complex and serious cases seen in everyday rhinosurgical practice.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.722-729
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• 2004

The horizontal movement of sloping ground due to flow liquefaction has caused many pile foundations to fail, especially those in ports and harbor structures. In this study, a virtual case is assumed in which flow liquefaction is induced by earthquake loads in a fully saturated infinite sand slope with a single pile installation. Under the assumption that the movement of liquefied ground is viscous fluid flow, the influence of ground movement due to flow liquefaction on the pile behavior was analyzed. Since the liquefied soil is assumed as a viscous fluid, its viscosity must be evaluated, and the viscosity was estimated by the dropping ball method ,md the pulling bar method. Finally, the influence of the flow of liquefied soil on a single pile installed in an infinite slope was analyzed by a numerical method.

• Journal of Information Processing Systems
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• 제10권3호
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• pp.395-411
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• 2014

Temporal medical data is often collected during patient treatments that require personal analysis. Each observation recorded in the temporal medical data is associated with measurements and time treatments. A major problem in the analysis of temporal medical data are the missing values that are caused, for example, by patients dropping out of a study before completion. Therefore, the imputation of missing data is an important step during pre-processing and can provide useful information before the data is mined. For each patient and each variable, this imputation replaces the missing data with a value drawn from an estimated distribution of that variable. In this paper, we propose a new method, called Newton's finite divided difference polynomial interpolation with condition order degree, for dealing with missing values in temporal medical data related to obesity. We compared the new imputation method with three existing subspace estimation techniques, including the k-nearest neighbor, local least squares, and natural cubic spline approaches. The performance of each approach was then evaluated by using the normalized root mean square error and the statistically significant test results. The experimental results have demonstrated that the proposed method provides the best fit with the smallest error and is more accurate than the other methods.

• 한국작물학회지
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• 제15권
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• pp.141-143
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• 1974

본답에서 재배되고 있는 방사선돌연변이계통들의 도열병 저항성 검정을 위하여 절리엽편접종법이 시도되었다. 즉 포장에서 절취한 잎을 항온항습실내에서 punch압상을 만들고 그 위에 도열병균의 포자현탁액을 접종한 후 형성된 병반의 크기를 측정하여 계통간의 저항성정도를 비교한 결과 방사선조사된 풍광으로부터 Upland short row method에 의하여 선발된 저항성계통들은 모품종 풍광에 비하여 저항성으로 나타났다. 따라서 이 방법은 포장에서 재배되는 성숙식물체의 도열병저항성 검정을 위한 하나의 선발방법으로서 효과적이라 생각되었다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권2호
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• pp.639-647
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• 2019

A realistic numerical simulation technology using a Lagrangian Fluid-Structure Interaction (FSI) model was combined with a fracture algorithm to predict the fluid-ice-structure interaction. The failure of ice was modeled as the tensile fracture of elastic material by applying a novel FSI model based on the Moving Particle Semi-implicit (MPS) method. To verify the developed fracture algorithm, a series of numerical simulations for 3-point bending tests with an ice beam were performed and compared with the experiments carried out in an ice room. For application of the developed FSI model, a dropping water droplet hitting a cantilever ice beam was simulated with and without the fracture algorithm. The simulation showed that the effects of fracture which can occur in the process of a FSI simulation can be studied.

• 정보보호학회논문지
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• 제26권3호
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• pp.655-659
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• 2016

본 논문에서는 IPv6를 적용한 표준인 IEEE 802.15.4e와 RPL을 기반으로 하는 사물인터넷 환경에서 가용성을 확보하기 위하여 패킷 유실 공격 탐지 기법과 우회 기법을 제안한다. RPL의 순위값과 패킷 유실 연속성을 고려하여 패킷 유실 탐지 메트릭을 개선하였고 RPL을 통해 생성된 라우팅 경로에서 형제노드 및 자식노드를 활용한 우회기법을 구성하였다. 시뮬레이션을 통해 제안한 탐지 기법의 탐지 속도가 향상되었음을 확인하였고 제안한 우회 기법의 우회 성공률이 향상되었음을 확인하였다.