• Journal of the Korea Society of Computer and Information
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• v.7 no.1
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• pp.94-102
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• 2002

In this paper, we present a forecasting model for the spectrum demand which will be used for the mid/long-term spectrum forecasting in Korea. In specific, we present the bottom-up model with considering the customer not the previous top-down method. The Proposed model consists of service definition. classification of service characteristics, drawing representative service characteristic , forecasting of service demand, mapping with spectrum resource, verification and spectrum forecasting. The carried actions in each step is described in detail. For the validation of the model an example for the PCS environments is shown. traverse stepping stones for a variety of legitimate reasons.

• Proceedings of the KSPS conference
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• 2006.05a
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• pp.41-44
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• 2006

The purpose of state tying is to reduce the number of models and to use relatively reliable output probability distributions. There are two approaches: one is top down clustering and the other is bottom up clustering. For seen data, the performance of bottom up approach is better than that of top down approach. In this paper, we propose a new clustering technique that can enhance the undertrained triphone clustering performance. The basic idea is to tie unreliable triphones before clustering. An unreliable triphone is the one that appears in the training data too infrequently to train the model accurately. We propose to use monophone distance to preprocess these unreliable triphones. It has been shown in a pilot experiment that the proposed method reduces the error rate significantly.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.6-8
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• 2007

In this paper, We propose reasoning system for object recognition and space classification using not only visual features but also contextual information. It is necessary to perceive object and classify space in real environments for mobile robot. especially vision based. Several visual features such as texture, SIFT. color are used for object recognition. Because of sensor uncertainty and object occlusion. there are many difficulties in vision-based perception. To show the validities of our reasoning system. experimental results will be illustrated. where object and space are inferred by bi -directional rules even with partial and uncertain information. And the system is combined with top-down and bottom-up approach.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.11a
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• pp.116-118
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• 2022

MPEG-VCM(Video Coding for Machine)은 입력된 이미지/비디오의 특징(feature)를 압축하는 Track 1 과 입력 이미지/비디오를 직접 압축하는 Track 2 로 나뉘어 표준화가 진행 중이다. 본 논문은 Track 1 의 비전임무 네트워크로 사용하는 Detectron2 의 FPN(Feature Pyramid Network)에서 추출한 멀티-스케일 특징을 효율적으로 압축하는 MSFC 기반의 압축 모델의 개선 기법을 제시한다. 제안기법은 해상도를 줄여서 단일-스케일 압축맵을 압축하는 기존의 압축 모델에서 저해상도 특징맵을 고해상도 특징맵에 바텀-업(Bottom-Up) 구조로 합성하여 단일-스케일 특징맵을 구성하는 바텀-업 MSFF 를 가지는 압축 모델을 제시한다. 제안방법은 기존의 모델 보다 BPP-mAP 성능에서 1 ~ 2.7%의 개선된 BD-rate 성능을 보이며 VCM 의 이미지 앵커(image anchor) 대비 최대 -85.94%의 BD-rate 성능향상을 보인다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.735-739
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• 2002

경제적 비용을 토대로 한 접속료 산정방식을 적용한다는 취지하에 주요 통신선진국에서는 장기증분비용 (LRIC ; Long Run Incremental Costs)모형에 대한 연구가 활발히 진행중에 있다. 이러한 LRIC 모형에는 미국의 HAI 모형, BCPM 모형, 일본 우정성 모형 둥의 공학적인 방법에 의한 LRIC 모형과 영국의 Top-Down 모형과 같이 회계적 자료를 바탕으로 한 LRIC 모형으로 구분될 수 있다. 이에 본고는 현재 세계적으로 선호되고 있는 Bottom-up 방식의 LRIC모형을 구축하기 위한 선진외국의 가입자망 재설계 방법을 살펴보았다.

• Review of Culture and Economy
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• v.19 no.2
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• pp.97-120
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• 2016

This study aims to identify how performing artists in Korea, who are the target beneficiaries of the Arts Council Korea's Performing Arts Fostering Program, Chang-jak-san-shil(CJSS), would perceive and assess the current state of CJSS and its effects. To do so, this paper has adopted a bottom-up approach as a theoretical lens for policy evaluative analysis. This research engages with qualitative research design by conducting a series of in-depth interviews and FGIs with 28 participants in total. The interview participants consist of CJSS grantees(n=21) and peer-review panels(n=7) based on the intension to enhance objectivity and reliability of the study. Results of the data analysis suggest that the grant program still carries pressing needs to achieve a success as follows: providing post-program support, enhancing transparency of the panel appointment process and the peer review process, reflecting different nature of each arts discipline, and having more open communications with arts professionals. Based on these findings, this paper will provide and discuss about policy implications which can contribute to the performing arts domain at large.

• Asia pacific journal of information systems
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• v.12 no.4
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• pp.21-36
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• 2002

This study empirically examined the effects of data warehousing methodology on the success of data warehousing. Research model and two hypotheses were set up to identify the relationships among two types of data warehousing methodology(top-down/bottom-up, dw configuration) and success based on the investigations of such theories as data warehousing, data warehousing methodology, IS success and so forth. And the survey instrument(questionnaire) was developed to collect data. Ultimately 183 questionnaires from 61 korean firms were collected. Findings showed that two types of data warehousing methodology affect significant effect on the success of data warehousing.

• The Korean Journal of Applied Statistics
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• v.31 no.2
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• pp.229-239
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• 2018

This paper introduces how to adopt the concept of temporal hierarchies to forecast time series data. Similarly as in hierarchical cross-sectional data, temporal hierarchies can be constructed for any time series data by means of non-overlapping temporal aggregation. Reconciliation forecasts with temporal hierarchies result in more accurate and robust forecasts when compared with the independent base and bottom-up forecasts. As an empirical example, we forecast traffic accident counts with temporal hierarchies and observe that reconciliation forecasts are superior to the base and bottom-up forecasts in terms of forecast accuracy.

• Journal of Internet Computing and Services
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• v.6 no.6
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• pp.107-115
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• 2005

A workflow procedure has recently become more complicated and large scaled. In this paper, we propose an advanced workflow modeling methodology, called a fragment driven cooperative workflow modeling methodology. which enables several real workflow designers to cooperatively define a workflow model. The methodology is a Bottom-Up approach in terms of integrating a set of fragment ICNs to compose a complete workflow model. Each fragment ICN is defined by each participant in the cooperative modeling session, We also use the ICN based formal description and the ICN based graphical notation as well. Finally, we prove the feasibility of the methodology by implementing a cooperative workflow modeling system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.571-578
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• 2012

In this paper, we propose two main points. The first is the constraint for logic synthesis, and the second is an efficient logic synthesis method. Logic synthesis is a process to obtain the gate-level netlist from RTL (register transfer level) codes using logic mapping and optimization with the specified constraints. The result of logic synthesis is tightly dependent on constraint and logic synthesis method. Since the size and timing can be dramatically changed by these, we should precisely consider them. In this paper, we present the considering items in the process of logic synthesis by using our experience and experimental results. The proposed techniques was applied to a circuit with the hardware resource of about 650K gates. The synthesis time for the hybrid method was reduced by 47% comparing the bottom-up method and It has better timing property about slack than top-down method.