• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제11권11호
• /
• pp.5377-5391
• /
• 2017

In this paper, we propose a new scheme to suppress the narrowband interference (NBI) in OFDM-based systems. The scheme utilizes code division multiple access (CDMA) and weighted-type fractional Fourier transform (WFRFT) domain preprocessing technologies. Through setting the WFRFT order, the scheme can switch into a single carrier (SC) or a multi-carrier (MC) frequency division multiple access block transmission system. The residual NBI can be eliminated to the maximum extent when the WFRFT order is selected properly. Final simulation results show that the proposed system can outperform MC and SC with CDMA and frequency domain preprocessing in terms of the narrowband interference suppression.

• International Journal of Contents
• /
• 제9권1호
• /
• pp.33-37
• /
• 2013

BCH code is one of the most widely used error correcting code for the detection and correction of random errors in the modern digital communication systems. The conventional BCH encoder that is operated in bit-serial manner cannot adequate with the recent high speed appliances. Therefore, parallel encoding algorithms are always a necessity. In this paper, we introduced a new systolic array type BCH parallel encoder. To study the area and speed, several parallel factors of the systolic array encoder is compared. Furthermore, to prove the efficiency of the proposed algorithm using tree-type structure, the throughput and the area overhead was compared with its counterparts also. The proposed BCH encoder has a great flexibility in parallelization and the speed was increased by 40% than the original one. The results were implemented on synthesis and simulation on FPGA using VHDL.

• 한국컴퓨터정보학회논문지
• /
• 제24권2호
• /
• pp.85-93
• /
• 2019

The purpose of this study is to provide basic data for the development of clothing which can improve the satisfaction of male university students' body shape by classifying the perception of body shape and examining characteristics by type. The types of recognition of body shape of male college students were classified into five types: developed upper body with protruding under abdomen, normal body with long legs, developed under body with big skeleton, skinny body, and ladder type normal body. The actual body shape was classified into three. The Y type had a long chest length and a shoulder developed, and the lower body silhouette was plain and short. Type H was flat with little protrusion from the chest to the hip. Type X has a larger hip and longer hip length than the waist. Body type was classified based on bust, waist, and hip circumference, but recognition body type was classified based on visual characteristics. It is thought that ergonomic consideration is needed to cover the disadvantages of each body type considering the aesthetic part as well as wearing comfort in accordance with the trend of the fashion market nowadays that the slim fit is generalized. This study was limited to male university students in their early 20s in Chungbuk province. Therefore, we could not grasp attitudes and perceptions of male university students living in other provinces. Therefore, we should pay attention to the generalization of the results of this study.

• 경영과정보연구
• /
• 제33권1호
• /
• pp.65-81
• /
• 2014

정보기술 서비스에 대한 많은 연구가 진행되었음에도 불구하고 정보기술 서비스를 이용 후 서비스 실패에 대한 회복과정을 살펴본 연구는 거의 진행되지 않았다. 본 연구에서는 스마트폰 애플리케이션 서비스 이용자를 대상으로 서비스 사용 실패 후 서비스 실패에 대한 회복과정을 살펴보고자 한다. 뿐만 아니라, 서비스 유형에 따라 사용 목적이 달라지듯 서비스 유형에 따라 회복과정도 달라질 것이라고 예상되기 때문에 서비스 유형에 따른 서비스 회복과정을 살펴보고자 한다. 이를 위해, 본 연구에서는 시나리오 기법을 통해 다양한 서비스 실패 유형을 선정하였고, 이를 기반으로 설문을 진행하였다. 연구 결과, 절차적 공정성과 상호 작용 공정성은 신뢰에 영향을 미치는 것으로 나타났으며, 신뢰는 모든 사용 품질에 영향을 끼치는 것으로 나타났다. 정보 품질 및 서비스 품질의 경우 로열티에 영향을 끼치는 것으로 나타났으며, 마지막으로 서비스 유형에 따라 조절효과가 있는 것으로 나타났다.

• 지능정보연구
• /
• 제7권2호
• /
• pp.95-115
• /
• 2001

본 논문에서는 우리나라 코스닥시장에 상장된 벤처기업을 대상으로 하여 지식경영 유형을 세분화 하기 위한 방법론을 제시한다. 이 방법론은 우선, 해당 벤처기업에 대하여 설문조사를 통하여 이들 회사의 지식경영 요인을 도출한 다음, 이들 요인 값을 가지고 비감독학습 인공신경망 모형인 SOM을 가지고 4개의 의미 있는 군집을 유도하였다. 이들 군집은 벤처기업이 수행하는 다양한 지식경영 유형을 나타내는 것으로 판명되었으며, 이들 유형은 각각 하이테크형, 조직지식중심형, 정보기술 중심형, 단순형으로 분류된다.

• 동아시아경상학회지
• /
• 제9권3호
• /
• pp.83-100
• /
• 2021

Purpose - The purpose of this study is to comprehensively understand the recent status of domestic e-commerce market and provide useful information for the revitalization of domestic on-line economy. This study looks over the association between type of e-commerce and demographic variables for each purchase ordering and sales order business. The demographics under consideration is administrative district, occupation and business organization type and type of e-commerce is B2B, B2C and B2G to deal with. Research design, data, and methodology - From January 2017 to December 2017, about 14000 samples are extracted from all businesses with experience in purchasing or selling products or services through e-commerce. The association between the two categorical variables considered by using two major statistical techniques such as chi-square test and correspondence analysis can be quantitatively and visually detected. Result - This study shows the association between the type of e-commerce with the administrative district and the occupation is completely different, but B2B and B2C are identical for organization type, with respect to both purchase and sales orders. Conclusion - The association between the type of e-commerce with the administrative district and the occupation is completely different, but B2B and B2C are identical for organization type, with respect to both purchase and sales orders.

• Journal of the Korean Data and Information Science Society
• /
• 제24권4호
• /
• pp.877-883
• /
• 2013

The quadratic inference functions (QIF) method proposed by Qu et al. (2000) and the generalized method of moments (GMM) for marginal regression analysis of longitudinal data with time-dependent covariates proposed by Lai and Small (2007) both are the methods based on generalized method of moment (GMM) introduced by Hansen (1982) and both use generalized estimating equations (GEE). Lai and Small (2007) divided time-dependent covariates into three types such as: Type I, Type II and Type III. In this paper, we compared these methods in the case of Type II and Type III in which full covariates conditional mean assumption (FCCM) is violated and interested in whether they can improve the results of GEE with independence working correlation. We show that in the marginal regression model with Type II time-dependent covariates, GMM Type II of Lai and Small (2007) provides more ecient result than QIF and for the Type III time-dependent covariates, QIF with independence working correlation and GMM Type III methods provide the same results. Our simulation study showed the same results.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권3호
• /
• pp.778-798
• /
• 2014

This paper proposes a novel exposed-terminal-eliminated medium access control (ETE-MAC) protocol by combining channel reservation, collision avoidance and concurrent transmissions to improve multi-access performance of the multihop wireless networks. Based on the proposed slot scheduling scheme, each node senses the control channel (CCH) or the data channel (DCH) to accurately determine whether it can send or receive the corresponding packets without collisions. Slot reservation on the CCH can be simultaneously executed with data packet transmissions on the DCH. Therefore, it resolves the hidden-terminal type and the exposed-terminal type problems efficiently, and obtains more spatial reuse of channel resources. Concurrent packet transmissions without extra network overheads are maximized. An analytical model combining Markov model and M/G/1 queuing theory is proposed to analyze its performance. The performance comparison between analysis and simulation shows that the analytical model is highly accurate. Finally, simulation results show that, the proposed protocol obviously outperforms the link-directionality-based dual-channel MAC protocol (DCP) and WiFlex in terms of the network throughput and the average packet delay.

• Journal of the Korean Data and Information Science Society
• /
• 제14권2호
• /
• pp.393-403
• /
• 2003

In this paper, various replacement policies for the general failure model are considered. There are two types of failure in the general failure model. One is Type I failure (minor failure) which can be removed by a minimal repair and the other is Type II failure (catastrophic failure) which can be removed only by a complete repair. In this model, when the unit fails at its age t, Type I failure occurs with probability 1-p(t) and Type II failure occurs with probability p(t), $0{\leq}p(t){\leq}1$. Under the model, optimal replacement policies for the long-run average cost rate and the limiting efficiency are considered. Also taking the cost and the efficiency into consideration at the same time, the properties of the optimal policies under the Cost-Priority-Criterion and the Efficiency-Priority-Criterion are obtained.

• 한국콘텐츠학회논문지
• /
• 제21권5호
• /
• pp.592-606
• /
• 2021

본 연구는 기업의 지식경영 유형별 지식경영전략과 지식경영결정요인이 지식활동에 미치는 영향을 살펴보고 각 기업의 상황과 여건이 다르므로 지식경영 유형에 따른 접근이 필요하여 초기형, 조직지식중심형, 정보기술중심형, 결합형으로 구분하여 지식관리시스템과 지식경영을 도입한 81개 기업을 대상으로 SPSS 18.0 프로그램을 이용하여 분석하였고, 그 결과는 초기형은 조직구조의 변화와 정보기술의 적극 수용을 통하여, 조직지식중심형은 개인 지식 극대화할 수 있는 관리시스템(최고경영자지원, 성과보상제도, 교육훈련제도)과 인프라구축 및 정보기술을 이용하며, 정보기술중심형은 조직지식보다는 인프라구축 및 정보기술이용 등 정보기술에 더 의존하여 지식창출과 지식활용하며, 결합형은 조직 전체 확대 위한 교육훈련제도 및 분권화 조직구조로 파악되었으며, 본 연구를 통해 유형별 효과적이고 유의한 전략과 지식경영 결정요인 및 지식활동에 대해서 제시하였다.