• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.916-918
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• 1995

This paper has researched designing methods and characteristics of the indoor two-way CATV amplifier to amplify the weak signals and to separate the signals in the forward and the reverse channels in the cable system. It consists of diplex filters, equalizers, attenuators and amplifier modules. With the experimental results for frequency response, gain and slope controls, noise figures, return losses, distortion characteristics, we concluded that the operating capabilities of the amplifier developed in this research satisfy the design conditions.

• 농촌지도와개발
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• 제23권2호
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• pp.115-122
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• 2016

For 20 years, Japanese government have been pushed forward supporting policy measures for youths who wanted to start farming. These measures made up a systematized scheme and brought out some effects. In this paper, those scheme are introduced and analyzed. Those are composed of several measeurs as following: vocational edcucation and training, internship program, direct payment for livelihood, and governmental subsidies for investment. Japanese scheme can be evaluated as a good policy in the view of Korean situation. There is no systematic policy program for youth's entrance to farming in Korea.

• 산업경영시스템학회지
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• 제32권4호
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• pp.72-78
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• 2009

Reverse logistics is the process of planning and controlling the recovery flow of end of life products. Industry is increasingly being confronted with the need to solve several reverse logistics issues because of not only stringent environmental legislations but also economic reasons. Recently, thanks to the advent of emerging technologies, such as RFID, enhancing the productivity of reverse logistics operations has been highlighted. The application of RFID technology is going beyond forward logistics, which is the delivery of manufactured goods to consumers, and being expanded, though not frequently yet, to reverse logistics, which includes return, recovery, reuse, reproduction and disposal. However, it requires a deep insight for the research of reverse logistics and new environment. In this regard, we studied effectiveness by applying RFID middleware technology to reverse logistics.

• 센서학회지
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• 제20권2호
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• pp.77-81
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• 2011

This paper presents a single-pole eight-throw(SP8T) switch based on proposed a radio-frequency(RF) microelectromechanical systems (MEMS) switches. The proposed switch was driven by a double stop(DS) comb drive, with a lateral resistive contact. Additionally, the proposed switch was designed to have tapered signal line and bi-directionally actuated. A forward actuation connects between signal lines and contact part, and the output becomes on-state. A reverse actuation connects between ground lines and contact part, and the output becomes off-state. The SP8T switch of 3-stage tree topology was developed based on an arrangement of the proposed RF MEMS switches. The developed SP8T switch had an actuation voltage of 12 V, an insertion loss of 1.3 dB, a return loss of 15.1 dB, and an isolation of 31.4 dB at 6 GHz.

• Clinics in Shoulder and Elbow
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• 제2권1호
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• pp.53-59
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• 1999

Initial treatment of multidirectional instability of the shoulder would be a thorough rehabilitation program. If rehabilitation fails to resolve a patient's symptoms, the most commonly performed surgical procedure remains the inferior capsular shift. Eleven patients who had disabling multidirectional instability of the shoulder were managed with the inferior capsular shift. All of the procedure were performed by means of an anterior approach and a laterally based capsular shift. All of the patients were the contact athletes. The purpose of our study was to evaluate the efficacy of the inferior capsular shift procedure in the contact athletic patients, to review the loss of external rotation postoperatively and to discuss their return to sports. Mean follow up duration was 14.5 months(range, 12 to 24). Pain was relieved postoperatively in all cases and most patients could get stability except one case of recurrent subluxation. The average loss of external rotation and forward flexion after the operation were Y and 30 at last follow up. By the rating scale from American Shoulder and Elbow Society, overall scores improved from 49 points to 85 points. The results were excellent or good in 9 patients(82%) out of 11 patients. In reference to return to sports, 10 patients(91 %) of 11 patients returned to their sports with 7 patients (64%) returning at the same levels of competitiveness. The inferior capsular shift procedure was considered to be a recommendable method for the management of the multidirectional instability of the shoulder.

• 한국위성정보통신학회논문지
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• 제7권1호
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• pp.65-74
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• 2012

다양한 유형의 사용자 패킷들이 다중화 되어 사용자 단말(RCST, Return Channel via Satellite Terminal)들에게 전달되는 위성 포워드링크에서 패킷들 간의 중요도에 따른 QoS 보장은 매우 중요하다. 특히 강우와 같은 기상상태에 따라 무선 채널 상태가 변화하는 위성망의 경우에는 가용 대역폭을 고려하면서 QoS가 보장 되도록 패킷을 처리해야 한다. DVB-S2에서는 강우감쇠에 대한 대책으로서 적응형 부호 및 변조(Adaptive Coding and Modulation, ACM) 기법을 사용하여 전송효율을 증가시킨다. 하지만 위성링크의 전송 지연시간이 크기 때문에, RCST들이 피드백 하는 리턴채널 데이터를 기반으로 전송모드를 결정하는 ACM 기법을 효율적으로 적용하기 위해서는 채널 예측 알고리즘이 필요하다. 이에 본 논문에서는 RCST가 피드백 하는 강우감쇠 값 데이터와 미리 저장된 참조데이터를 이용하여 위성 링크의 채널을 예측하는 알고리즘 및 QoS와 공평성을 동시에 보장하는 스케줄링 기법을 제안한다. 성능평가 결과 제안하는 알고리즘이 채널을 정확히 예측함은 물론 QoS를 보장하면서 동시에 각 RCST들 간의 사용 대역폭의 공평성을 지원함을 보였다.

• Journal of Information Technology Applications and Management
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• 제19권1호
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• pp.1-12
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• 2012

Data mining is the process of searching and analyzing large quantities of data for finding out meaningful patterns and rules. Artificial Neural Network (ANN) is one of the tools of data mining which is becoming very popular in forecasting the future values. Some of the areas where it is used are banking, medicine, retailing and fraud detection. In finance, artificial neural network is used in various disciplines including stock market forecasting. In the stock market time series, due to high volatility, it is very important to choose a model which reads volatility and forecasts the future values considering volatility as one of the major attributes for forecasting. In this paper, an attempt is made to develop two models - one using feed forward back propagation Artificial Neural Network and the other using Autoregressive Conditional Heteroskedasticity (ARCH) technique for forecasting stock market returns. Various parameters which are considered for the design of optimal ANN model development are input and output data normalization, transfer function and neuron/s at input, hidden and output layers, number of hidden layers, values with respect to momentum, learning rate and error tolerance. Simulations have been done using prices of daily close of Sensex. Stock market returns are chosen as input data and output is the forecasted return. Simulations of the Model have been done using MATLAB$^{(R)}$ 6.1.0.450 and EViews 4.1. Convergence and performance of models have been evaluated on the basis of the simulation results. Performance evaluation is done on the basis of the errors calculated between the actual and predicted values.

• 한국멀티미디어학회논문지
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• 제12권11호
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• pp.1671-1679
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• 2009

기존에는 제품의 원부자재 조달, 생산, 유통, 판매 등 기업과 고객을 연결하는 공급사슬관리의 대상이 순방향 물류(forward logistics)에 초점을 두어 왔으나, 그 범위가 역방향 물류(reverse logistics)로 확대되고 있다. 그러나 해외 선진기업들에 비해 국내 기업들의 역 공급사슬(reverse supply chain) 관리 능력은 강대적으로 저조한 수준에 머물러 있으며, 구체적으로 이를 수행할 수 있는 체계적인 인프라를 구축하고 있지 못한 실정이다. 이에 본 연구에서는 순방향 물류에 광범위하게 적용되고 있는 RFID 기술을 적용하여 포장, 보관, 하역, 운송 등 기존의 물류관리에 필요한 필수정보는 물론, 반품, 회수, 폐기, 재활용 등 친환경 공급사슬 관리를 수행하기 위한 정보를 제공하는 서비스 플랫폼을 개발하고자 하였다. 이를 위해 역방향 물류에 관한 문헌연구 및 선진사례를 분석하고, 국내외 추진현황을 검토하며 향후 적용되어야 할 역 공급사슬 관리를 위한 서비스 플랫폼을 제안한다.

• 한국환경과학회지
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• 제13권8호
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• pp.721-731
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• 2004

The dispersion of suspended particulates in the coastal complex terrain of mountain-inland basin (city)-sea, considering their recycling was investigated using three-dimensional non-hydrostatic numerical model and lagrangian particle model (or random walk model). Convective boundary layer under synoptic scale westerly wind is developed with a thickness of about I km over the ground in the west of the mountain, while a thickness of thermal internal boundary layer (TIBL) is only confined to less than 200m along the eastern slope of the mountain, below an easterly sea breeze circulation. At the mid of the eastern slop of the mountain, westerly wind confronts easterly sea breeze, which goes to the height of 1700 m above sea level and is finally eastward return flow toward the sea. At this time, particulates floated from the ground surface of the city to the top of TIBL go along the eastern slope of the mountain in the passage of sea breeze, being away the TIBL and reach near the top of the mountain. Then those particulates disperse eastward below the height of sea-breeze circulation and widely spread out over the coastal sea. Total suspended particulate concentration near the ground surface of the city is very low. On the other hand, nighttime radiative cooling produces a shallow nocturnal surface inversion layer (NSIL) of 200 m thickness over the inland surface, but relatively thin thickness less than 100m is found near the mountain surface. As synoptic scale westerly wind should be intensified under the association of mountain wind along the eastern slope of mountain to inland plain and further combine with land-breeze from inland plain toward sea, resulting in strong wind as internal gravity waves with a hydraulic jump motion bounding up to about 1km upper level in the atmosphere in the west of the city and becoming a eastward return flow. Simultaneously, wind near the eastern coastal side of the city was moderate. Since the downward strong wind penetrated into the city, the particulate matters floated near the top of the mountain in the day also moved down along the eastern slope of the mountain, reaching the. downtown and merging in the ground surface inside the NSIL with a maximum ground level concentration of total suspended particulates (TSP) at 0300 LST. Some of them were bounded up from the ground surface to the 1km upper level and the others were forward to the coastal sea surface, showing their dispersions from the coastal NSIL toward the propagation area of internal gravity waves. On the next day at 0600 LST and 0900 LST, the dispersed particulates into the coastal sea could return to the coastal inland area under the influence of sea breeze and the recycled particulates combine with emitted ones from the ground surface, resulting in relatively high TSP concentration. Later, they float again up to the thermal internal boundary layer, following sea breeze circulation.

• ETRI Journal
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• 제30권2호
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• pp.261-267
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• 2008

In this paper, we propose and demonstrate a cost-effective technique to upgrade the capacity of dense wavelength division multiplexing (DWDM) networks to a 40 Gb/s line rate using the existing 10 Gb/s-based infrastructure. To accommodate 40 Gb/s over the link optimized for 10 Gb/s, we propose applying a combination of super-FEC, carrier-suppressed return-to-zero, and pre-emphasis to the 40 Gb/s transponder. The transmission of 40 Gb/s DWDM channels over existing 10 Gb/s line-rate long-haul DWDM links, including $40{\times}40$ Gb/s transmission over KT's standard single-mode fiber optimized for 10 Gb/s achieves successful results. The proposed upgrading technique allows the Q-value margin for a 40 Gb/s line rate to be compatible with that of 10 Gb/s.