• 한국통신학회논문지
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• 제27권3A호
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• pp.180-187
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• 2002

커버링 다항식을 이용한 복호는 오류 포착 복호의 확장된 형태로써, 순환 부호에 적용되어 간단하고도 효율적인 복호기 구현을 가능하게 한다. 커버링 다항식은 한계 거리 이상의 복호와 연판정 복호에도 사용될 수 있으며, 구현 복잡도는 사장되는 커버링 다항식의 개수에 비례하게 된다. 본 논문에서는 커버링 다항식을 이용한 연판정 복호 방법을 제시하고 이를 [23,12] 골레이 코드에 적용하였다. 적용을 위하여 새로운 커버링 다항식 집합을 일반화된 공식으로 유도하고, 이 집합이 골레이 부호를 비롯한 다수의 순환 부호에 효율적으로 활용될 수 있음을 보였다. 또한 제시된 방법을 사용한 복호기의 성능 평가 모의 실험을 수행하여 복잡도와 성능의 trade-off관계를 보였다. 유도된 커버링 다항식을 사용한 골레이 부호의 연판정 복호 시, 최대 유사도 복호가 갖는 최적 오율과 비교하여 전체 실험 구간에서 0.2dB 이내의 성능을 보였으며, 유사한 성능을 갖는 Chase 알고리듬 2와 경판정 복호가 결합된 경우에 비해 복잡도가 감소함을 확인하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권3호
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• pp.784-793
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• 2012

This paper deals with subcarrier allocation strategies for soft hand-over in OFDMA-based cellular systems. Two possible subcarrier allocation methods are considered for soft hand-over. One method is to use an identical subcarrier set between the two cells participating in the hand-over. The other is to use different subcarrier sets between the two cells. As expected, the different subcarrier strategy is better in terms of diversity order and BER than the identical subcarrier strategy. It will be shown that the BER performance difference between the two strategies is more noticeable with contiguous subcarrier allocation. But the different subcarrier strategy consumes twice more frequency resources than the other, and there is a trade-off between the two strategies in terms of BER and frequency resources. By considering the trade-off, we also propose a subcarrier allocation strategy for soft hand-over.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권9호
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• pp.1596-1612
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• 2011

Coordinated Multi-Point (CoMP) transmission / reception is being studied in Long Term Evolution-Advanced (LTE-A) for future evolution of the $3^{rd}$ Generation Partnership Project (3GPP) LTE. Support of soft handover is essential for improving the performance of cell edge users. CoMP provides a natural framework for enabling soft handover in the LTE system. This paper evaluates the soft handover gain in LTE-A downlink. Mathematical analysis of signal to interference plus noise ratio (SINR) gain and the handover margins for soft handover and hard handover are derived. CoMP system model is developed and an inter-cell and intra-cell interference model is derived, taking into account the pathloss, shadowing, cell loading, and traffic activity. Reference signal received power (RSRP) is used to define the triggers and the measurements for soft handover. Our results indicate that parameter choices such as handover margin and the CoMP set size impact CoMP performance gain.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.4106-4106
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• 2001

A method to discriminate human gallstones by nea. infrared(NIR) spectrometry using a soft independent modeling of class analogy (SIMCA) has been studied. The fifty NIR spectra of gallstones in the wavenumber range from 4500 to 10,000 cm$\^$-1/ were measured. The forty samples were classified to three classes, cholesterol stone, calcium bilirubinate stone and calcium carbonate stone according to the contents of major components in each gallstone. The training set which contained objects of the different known class was constructed using forty NIR spectra and the test set was made with ten different gallstone spectra. The number of important principal components(PCs) to describe the class was determined by cross validation in order to improve the decision criterion of the SIMCA for the training set. The score plots of the class training set whose objects belong to the other classes were inspected. The critical distance of each class was computed using both the Euclidean distance and the Mahalanobis distance at a proper level of significance(${\alpha}$). Two methods were compared with respect to classification and their robustness towards the number of PCs selected to describe different classes.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.103-109
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• 2001

Soft sensor is an effective method to deal with the estimation of variables, which are difficult to measure because of the reasons of economy or technology. Fuzzy logic system can be used to develop the soft sensor model by infinite rules, but the fuzzy dividing of variable sets is a key problem to achieve an accurate fuzzy logic model, In this paper, we proposed a new method to develop soft sensor model based on fuzzy neural network. First, using a novel method to divide the variable fuzzy sets by the process input and output data. Second, developing the fuzzy logic model based on that fuzzy set dividing. After that, expressing the fuzzy system with a fuzzy neural network and getting the initial soft sensor model based FNN. Last, adjusting the relative parameters of soft sensor model by the BP learning method. The effectiveness of the method proposed and the preferable generalization ability of soft sensor model built are demonstrated by the simulation.

• 한국산학기술학회논문지
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• 제10권12호
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• pp.3768-3774
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• 2009

본 연구에서는 중소기업진흥공단이 보유하고 있는 중소기업의 정책자금 대출신청자료를 활용해서 정책자금 대출심사 시에 연성정보와 경성정보를 어느 정도 활용되고 있는지에 대해서 분석하였다. 실증분석에 사용되는 주요데이터는 2004년 이후 중소기업진흥공단에서 정책자금 지원기업에 대한 심사 시에 사용하는 기업의 재무자료 및 비재무자료 관련 데이터이다. 본 연구에서는 비재무 정보를 연성정보(soft information)로 간주하였다. 정책자금 대출심사시에 사용되는 신용정보, 연성정보, 재무정보 등의 상대적 중요성을 로짓모형을 통해 살펴본 결과, 신용정보의 추정값이 가장 크며, 그 다음으로 연성정보, 재무정보의 추정값은 가장 작다. 대출심사에 있어서 신용정보의 추정값이 상대적으로 가장 큰 것은 중진공에서 최종적인 대출승인 여부를 재무정보와 비재무(연성)정보의 결합인 신용정보를 토대로 결정하기 때문에 나타난 당연한 결과라고 봐야한다. 그리고 신용정보의 구성요소인 재무정보와 연성정보의 상대적 중요성을 살펴보면, 상대적으로 연성정보가 대출결정여부에 더 결정적으로 기여하고 있다고 할 수 있다. 이는 중진공의 정책자금을 신청하는 중소기업의 대부분은 영세한 기업이어서 재무제표 정보의 신빙성이 낮은 반면, 상대적으로 재무정보 외의 정보들이 기업평가에 더 많은 중요성을 가지고 있기 때문이다. 결론적으로, 재무정보와 연성정보의 결합인 신용정보가 대출결정에 결정적인 영향을 미치고 있음을 알 수 있다. 그러나 연성정보와 재무정보를 비교해 보면, 연성정보가 대출결정에 더 많은 영향을 미치고 있음을 알 수 있다. 그리고 대출심사 시, 기업의 지역별 특성을 나타내는 변수들의 중요성은 없어졌다고 할 수 있다.

• 한국경영과학회지
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• 제25권2호
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• pp.77-86
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• 2000

Consumers facing a large number of brands to choose from are known to use simplified heuristic to screen a set of relevant brands called the consideration set from the whole alternatives, Purchase decisions are then made from the brands in the consideration set, Two approaches have been suggested to model the two-stage choice process., One is to treat the con-sideration set as a crisp set (e.g Roberts and Lattin 1991) The other is to treat the set as a fuzzy set (e.g. Fortheringham 1988) The paper empirically compares the two types of models using data for soft drinks sneakers and departments. The results show that a model employing the crisp set approach fits the data better than that with the fuzzy set approach and better than a single-stage choice logit model.

• 한국의류학회지
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• 제44권6호
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• pp.1154-1162
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• 2020

In this study, the soft textile actuator is produced for a smart wearable with the shape memory effects from linear shape memory alloys of Nickel and Titanium using the driving force through the fabrication process. The measurement model was designed to measure dynamic characteristics. The heating method, and memory shape of the linear shape memory alloy were set to measure the operating temperature. A shape memory alloy at 40.13℃, was used to heat the alloy with a power supply for the selective operation and rapid reaction speed. The required amount of current was obtained by calculating the amount of heat and (considering the prevention of overheating) set to 1.3 A. The fabrication process produced a soft textile actuator using a stitching technique for linear shape memory alloys at 0.5 mm intervals in the general fabric. The dynamic characteristics of linear shape memory alloys and actuators were measured and compared. For manufactured soft textile actuators, up to 0.8 N, twice the force of the single linear shape memory alloy, 0.38 N, and the response time was measured at 50 s.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.191-196
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• 2007

With the development of micro electronic circuits and optical equipment, the demand for developing smart munitions with the ability to autonomously search for and attack targets has increased. Since the electronic components within smart munitions are affected by high temperatures, pressure, and impulsive forces upon the combustion of gunpowder, stability and reliability need to be secured for them. Securing those stability and reliability requires soft recovery system which can decelerate smart munitions. A theoretical analysis of flow is performed for the secure recovery of bullets on the basis of Navier-Stokes equation for compressible fluids. The inner pressure on a pressure tube, the speeds of bullets, and the deceleration of munitions are calculated theoretically. Theoretical results are compared with the data from the experiment with soft recovery system set up at the laboratory.

• 한국시뮬레이션학회논문지
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• 제7권2호
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• pp.153-165
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• 1998

In the Is-95 soft handoff scheme of CDMA, there occurs a tradeoff between improving quality due to the space diversity and additional resource management like updates of the active set during soft handoffs. In addition, if a mobile terminal is alternating two adjacent cells, a well-known phenomenon called ping-ping causes the resource management to be seriously degraded. By noting that in general the probability that a user initiates additional handoffs is exponentially decreased as the user has already handed over one or more times, we present a soft handoff algorithm making use of handoff profiles of mobile terminals to improve resource utilization. In the proposed algorithm the number of handoffs made so far during the call is recorded in the mobile profile and the profile data is used for adjusting handoff parameters such as the value of add or drop threshold (T_ADD or T_DROP). Through simulations, the result of the proposed algorithm is shown to improve the handoff performance by lowering the number of handoffs while simultaneously reducing resource waste.