• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.12A
• /
• pp.1223-1228
• /
• 2006

Closed-form expressions for capacity bounds of multiuser diversity combined with maximum ratio transmission (MRT) and maximum ratio combining (MRC) at each link are presented under the assumption of independent and quasi-static flat multiple-input multiple-output (MIMO) Rayleigh fading channels. The analysis results precisely agree with the numerical verification results and clearly show the impact of MRT/MRC on multiuser diversity.

• ETRI Journal
• /
• v.31 no.4
• /
• pp.454-456
• /
• 2009

The maximum likelihood linear spectral transformation (ML-LST) using a numerical iteration method has been previously proposed for robust speech recognition. The numerical iteration method is not appropriate for real-time applications due to its computational complexity. In order to reduce the computational cost, the objective function of the ML-LST is approximated and a closed-form solution is proposed in this paper. It is shown experimentally that the proposed closed-form solution for the ML-LST can provide rapid speaker and environment adaptation for robust speech recognition.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.1
• /
• pp.485-489
• /
• 2006

In last decades, several linearization methods for the AOA measurements have been proposed, for example, Gauss-Newton method and closed-form solution. Gauss-Newton method can achieve high accuracy, but the convergence of the iterative process is not always ensured if the initial guess is not accurate enough. Closed-form solution provides a non-iterative solution and it is less computational. It does not suffer from convergence problem, but estimation error is somewhat larger. This paper proposes a self-tuning weighted least square AOA algorithm that is a modified version of the conventional closed-form solution. In order to estimate the error covariance matrix as a weight, two-step estimation technique is used. Simulation results show that the proposed method has smaller positioning error compared to the existing methods.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.10b
• /
• pp.257-259
• /
• 2000

다양한 전자문서를 효율적으로 처리하기 위해서는 구조문서 정의가 가능한 SGML(Standard Generalized Markup Language)이나 XML(eXtensible Markup Language)을 이용할 수 있다[1,2]. SGML 및 XML과 같은 구조문서를 생성하기 위해서는 별도의 편집기가 필요하며 현재 다양한 제품이나 연구결과를 살펴볼 수 있다[3,4]. 그러나 기존의 입력, 편집 시스템에서는 사용자가 작성하려는 문서에 대한 구조를 숙지하여야 하는 동시에, DTD(Document Type Definition)에 대한 지식을 필요로 한다. 이를 인해 복잡한 구조의 SGML 및 XML 문서를 일반인들이 사용하기 어렵고, 작성한 결과에 대한 검증 과정이 필수적으로 요구된다. 또한 다양한 분야에서 적용 가능한 전자문서 시스템을 위해서는 효과적인 통합 DTD의 정의와 처리 방법이 필요하다. 따라서 본 논문에서는 구조화 문서에 대한 지식이 없는 일반인들도 쉽게 구조문서 작성이 가능하며, 통합적 DTD의 효율적인 처리가 가능한 Form 기반 편집 시스템의 모델을 제시하며, 특히 웹에서도 적용이 가능한 XML을 지원한다. 그 결과 본 연구에서 개발한 XML 편집 시스템은 Form 기반의 통합 DTD 처리와 XML 문서 작성 및 출력 기능, 그리고 이미지, 테이블 기능 등을 제공함으로써 누구나 쉽고 정확한 XML 문서를 작성할 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.6
• /
• pp.1082-1086
• /
• 2008

Multiple-input multiple-output (MIMO) is an efficient technology to increase data rate in wireless networks due to bandwidth and power limitations. Data transmission rate between transmitter and receiver is determined by channel capacity. MIMO has an advantage of reliable communication over wireless channel because of utilizing the channel capacity properly. In this letter, we drive a new formula, closed form capacity formula, using confluent hypergeometric function.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.05a
• /
• pp.166-167
• /
• 2016

Unlike the past, supported by the development of digital technologies, free-form buildings are frequently designed with creative thoughts of architectural designers. However, there are some difficulties preventing successfully completion of projects, like reduced productivity and increased construction duration and cost upon the process of producing and installing concrete panels for free-form structures. In particular, there are active studies on the CNC machine for production of free-form concrete panels. Yet, it is difficult to effectively and easily come up with information on production and installation of free-form, curve-surfaced panels which are difficult to be mathematically defined. This requires a lot of manpower and time to implement the curved surfaces of free-form buildings as intended by architects. Accordingly, it needs a model that can effectively create production-installation data of free-form concrete panels for successful free-form building projects. Thus, the purpose of the study is to suggest data estimation model of production-installation using mathematical algorithm in free-form concrete panels. The study results will realize effective production and installation of free-form concrete members, allowing improved productivity of projects, reduced cost and shortened construction duration.

• Journal of the Korean Society of Physical Medicine
• /
• v.6 no.4
• /
• pp.425-436
• /
• 2011

Purpose : The purpose of this study is to identify static, dynamic balance performances and foot pressure after eye movement exercise in normal adults. Method : This study was performed on normal 18 males and 18 females subjects. They were divided into 3 groups using random sampling and executed saccadic eye movement, vestibuloocular eye movement, pursuit vergence eye movement exercise respectively. In order to compare the difference of balance and foot pressure, the subjects were measured before, middle and after eye movement. Balance was examined using the balance master 7.0 version systems. Foot pressure was examined using the gaitview AFA-50. Result : The result are as follows. 1. After first intervention, the difference of the FORM-EC item on MCTSIB variable in the vestibuloocular group was significantly decreased(p<.05) and after second intervention, the difference of the FIRM-EO(p<.05), FORM-EO(p<.01), FORM-EC(p<.01) items on MCTSIB variable in the saccadic group and FORM-EC(p<.05) item in the vestibuloocular group were significantly decreased respectively. 2. After first intervention, the difference of the EPE, MXE items in the saccadic group(p<.05) and RT(p<.05), EPE(p<.01) items in the pursuit vergence group were significantly decreased respectively after second intervention. 3. After first intervention, the difference of the Static A-P(p<.05), L-R(p<.01) and Dynamic A-P(p<.01), L-R (p<.01) items on foot pressure variable in the saccadic group, Dynamic A-P(p<.01) item in the vestibuloocular group and Static A-P(p<.01), Dynamic A-P(p<.05), L-R(p<.01) items in the pursuit vergence group were significantly decreased respectively. 4. After first intervention, the difference of the FORM-EO(p<.05), FORM-EC(p<.01) items and after second intervention, the difference of the FIRM-EO(p<.01) item on MCTSIB variable among three groups was significantly decreased respectively. Conclusion : Selective eye movement exercise program influences balance control ability and foot pressure of normal adults in positive ways.

• Journal of the Korea Society of Computer and Information
• /
• v.29 no.2
• /
• pp.109-118
• /
• 2024

With the increasing number of social media users worldwide, cases of social media being abused to perpetrate various crimes are increasing. Specifically, drug distribution through social media is emerging as a serious social problem. Using social media channels, the curiosity of teenagers regarding drugs is stimulated through clever marketing. Further, social media easily facilitates drug purchases due to the high accessibility of drug sellers and consumers. Among various social media platforms, we focused on Instagram, which is the most used social media platform by young adults aged 19 to 24 years in South Korea. We collected four types of information, including profile photos, introductions, posts in the form of images, and posts in the form of texts on Instagram; then, we analyzed the similarity among each type of collected information. The profile photos and posts in the form of image were analyzed for similarity based on the SSIM(Structural Simplicity Index Measure), while introductions and posts in the form of text were analyzed for similarity using Jaccard and Cosine similarity techniques. Through the similarity analysis, the similarity among various accounts for each collected information type was measured, and accounts with similarity above the significance level were determined as the same drug sales account. By performing logistic regression analysis on the aforementioned information types, we confirmed that except posts in image form, profile photos, introductions, and posts in the text form were valid information for tracking the same drug sales account.

• Journal of the Korean Data and Information Science Society
• /
• v.19 no.2
• /
• pp.497-504
• /
• 2008

In this paper we studied the saddlepoint approximations to the distribution of quadratic forms in normal variables. We derived the approximations as a special case of Na & Kim (2005). Also applications to a statistic which concerns intraclass correlation coefficient are presented. Simulations show the accuracy and availability of the suggested approximations.

• Journal of Ocean Engineering and Technology
• /
• v.12 no.3 s.29
• /
• pp.103-111
• /
• 1998

This paper describes the initial hull form design process which generate a hull form using a neurofuzzy modeling. Neurofuzzy system is to combine the merits of fuzzy inference system and neural networks. Therefore it has structured knowledge representations as well as adaptive capacities. Initial hull form design stage is the process which generate an adoptable hull form from the limited design information and multi-decidions condidering correlations with design factors. It can be assidted efficiently by neurofuzzy system. This paper suggests two methods of an initial hull form generation using the neurofuzzy modeling and B-spline theory. and examines the usefulness of suggested method through its application examples.