• Journal of Communications and Networks
• /
• 제5권4호
• /
• pp.303-308
• /
• 2003

We present a statistical model for the path loss of ultrawideband (UWB) channels in indoor environments. In contrast to our previously reported measurements, the data reported here are for a bandwidth of 6GHz rather than 1.25GHz; they encompass commercial buildings in addition to single-family homes (20 of each); and local spatial averaging is included. As before, the center frequency is 5.0GHz. Separate models are given for commercial and residential environments and, within each category, for lineof sight (LOS) and non-line-of-sight (NLS) paths. All four models have the same mathematical structure, differing only in their numerical parameters. The two new models (LOS and NLS) for residences closely match those derived from the previous measurements, thus affirming the stability of our path loss modeling. We find, also, that the path loss statistics for the two categories of buildings are quite similar.

• 시스템엔지니어링학술지
• /
• 제8권1호
• /
• pp.77-82
• /
• 2012

In Weapons acquisition process, if the requirements are not clear, it leads to confusion and conflict in business. In the development of next-generation weapons, to define and derive requirements has to start from decision of operational concept. It is difficult task and has many uncertainties. This paper has goal about development of knowledge acquisition process that derive military operational scenario-based requirements acquisition process and framework that classify and save the derived requirements for next project. That framework can generate new class and category, also suggest that verification of requirements. It help to derive and manage the requirements, and make it easy to grasp the requirements. Accordingly, it can help make military requirement plan and weapon acquisition process.

• 해양환경안전학회지
• /
• 제24권3호
• /
• pp.319-324
• /
• 2018

The collision problem is one of the design factors that must be carefully considered for the risk of collision occurring during the operation of ships and offshore structures. This paper presents the main results of the ship collision study, and its main goal is to analyze potential crash scenarios that may occur in the FLNG (Floating Liquefied Natural Gas) considering the likelihood and outcome. Consideration being given to vessels visiting the FLNG and surrounding vessels navigating around, such as functionally supported vessels and offloading carriers. The scope includes vessels visiting the FLNG facility such as in-field support vessels and off-loading carriers, as well as third party passing vessels. In this study, based on QRA (quantitative risk assessment), basic research methods and information on collision are provided. Based on the assumptions and methodologies documented in this study, it has been possible to clarify the frequency of collision and the damage category according to the type of visiting ship. Based on these results, the risk assessment results related to the collision have been derived.

• Wind and Structures
• /
• 제23권5호
• /
• pp.385-403
• /
• 2016

The across-wind dynamic loads on L-shaped tall buildings with various geometric dimensions were investigated through a series of wind tunnel testing. The lift coefficients, power spectral densities and vertical correlation coefficients of the across-wind loads were analyzed and discussed in details. Taking the side ratio and terrain category as key variables, empirical formulas for estimating the across-wind dynamic loads on L-shaped tall buildings were proposed on the basis of the wind tunnel testing results. Comparisons between the predictions by the empirical formulas and the wind tunnel test results were made to verify the accuracy and applicability of the proposed formulas. Moreover, a simplified procedure to evaluate the across-wind dynamic loads on L-shaped tall buildings was derived from the proposed formulas. This study aims to provide a simple and reliable way for the estimation of across-wind dynamic loads on L-shaped tall buildings.

• Clinical and Experimental Pediatrics
• /
• 제52권6호
• /
• pp.643-648
• /
• 2009

Blood eosinophilia can be classified as either familial or acquired. Familial eosinophilia is a rare autosomal dominant disorder characterized by a stable eosinophil count. Acquired eosinophilia is classified further into a primary or secondary phenomenon depending on whether eosinophils are considered integral to the underlying disease. Primary eosinophilia is considered clonal in the presence of either a cytogenetic abnormality or bone marrow histological evidence of classified hematologic malignancies. Causes of secondary eosinophilia include infections, allergic or immunologic disorders, and drugs. Idiopathic eosinophilia belongs to a category of primary eosinophilia, and this is a diagnosis of exclusion. Cases with eosinophilia that lack evidence of clonality may be diagnosed as idiopathic hypereosinophilic syndrome after all causes of reactive eosinophilia have been eliminated. Genetic mutations involving the platelet-derived growth receptor genes (PDGFRA and PDGFRB) have been pathogenetically linked to clonal eosinophilia, and their presence predicts the treatment response to imatinib. In this review, I will present a clinical summary of both familial and acquired eosinophilia with emphasis on recent developments in molecular pathogenesis and treatment.

• 한국품질경영학회:학술대회논문집
• /
• 한국품질경영학회 2006년도 추계 학술대회
• /
• pp.174-180
• /
• 2006

This study to find out key ingredients(KIs) of Six Sigma. Potential ingredients are selected from previous studies of success factors and ingredients of Six Sigma and TQM, and criteria of quality awards like MBNQA, EFQM, Deming and Korean National Quality Award(KNQA) are classified into 11 categories based on experts' opinion and affinity analysis. Irrelevant or ineffective potential ingredients are discarded by using factor analysis for the questionnaires answered by champions, MBBs and BBs of 90 Korean companies that have more than 3 years of experience in implementing Six Sigma. In addition, from the factor analysis, 3 factors are derived for each respectively except the managerial achievement category. Those 11 categories and 30 factors are defined as Six Sigma KIs.

• 산업공학
• /
• 제25권4호
• /
• pp.376-381
• /
• 2012

As the number, complexity and interaction of electrical, electronic and programmable electronic (E/E/PE) systems increase, a growing emphasis has been placed on the concept of functional safety during product development. IEC 61508 provides guidelines and standardized procedures in the development of reliable and dependable E/E/PE systems to assure functional safety. Determining risk classes (i.e., safety integrity levels, SILs) associated to a specific E/E/PE item may be recognized as one of the most crucial activities in the product development per IEC 61508 since SILs are used to specify necessary safety requirements for achieving an acceptable residual risk. This article presents a case study on the assessment of SILs applying failure modes, effects and diagnostic analysis (FMEDA) from which failure rates may be derived for each important failure category by combining a standard FMEA with online diagnostic techniques.

• 한국공간구조학회논문집
• /
• 제4권1호
• /
• pp.39-48
• /
• 2004

Generally, a structural system with large inextensional deformations, or in other words, non-strained deformation is called as 'Unstable Structure', Truss-linked structures, cable structures, membrane structures and movable structures as foldable space structures etc, are included in this category. In this paper, a dynamic analysis method for unstable structural systems is presented. Governing equations for dynamic analysis of unstable truss structures with inextensional displacements are derived. Because of singularity of inverse matrixin in practical analysis of unstable structure, the generalized inverse matrix is Introduced to resolve the singular problem. Also, the RREF technique is used to get the inextensional displacement mode. Two unstable truss structures are analyzed by using presented method. Damping is not considered. From the given results, it is known that proposed method is useful to figure out the dynamic behavior of unstable truss structures.

• 한국언어정보학회지:언어와정보
• /
• 제7권2호
• /
• pp.117-137
• /
• 2003

This paper attempts to provide an alternative analysis involving categorical issues related to English gerunds. Especially, this paper rejects Maulof's approach that creates a new syntactic category gerund by mixing nominal and verbal categories. This paper identifies two syntactic structures in English gerunds: nominal gerunds and verbal gerunds. This distinction is based on syntactic and semantic characteristics of each type and is intended to account for the external distribution and endocentricity of the construction. Treating verbal gerunds syntactically as verbal categories, this paper proposes that English verbal gerunds act like other verbal categories such as infinitives whereas nominal gerunds behaves much like derived nominals. This paper proposes a few lexical rules that can take care of the two types of gerunds. The proposal can be extended to prepositional complements as well as sentential subject positions. This proposal not only resolves the issues involving distributional properties of the gerund construction but also captures syntactic parallelism observable between gerunds and other verbal constructions in English.

• 대한수학회지
• /
• 제56권2호
• /
• pp.387-419
• /
• 2019

A fullness conjecture of Kuznetsov says that if a smooth projective variety X admits a full exceptional collection of line bundles of length l, then any exceptional collection of line bundles of length l is full. In this paper, we show that this conjecture holds for X as the blow-up of ${\mathbb{P}}^3$ at a point, a line, or a twisted cubic curve, i.e., any exceptional collection of line bundles of length 6 on X is full. Moreover, we obtain an explicit classification of full exceptional collections of line bundles on such X.