• 대한산업공학회지
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• 제24권3호
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• pp.457-473
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• 1998

As a product structure or BOM(bill of material) of products is hierarchically structured, the design based on the concept of relational data base modeling causes low performances in data search or processing. For this reason, an object-oriented approach to designing a product structure is proposed in this paper. Using Rumbaugh's OMT (Object Modeling Technique) method, classes of parts, BOM structure, options, and models are defined and their class-relationship diagrams are proposed. For the representation of the BOM structure suitable for the object-oriented paradigm, a new data architecture called the BOM item class is suggested. It is expected that the proposed data structure ensures better reusability and expandability due to the modularity.

• 대한지리학회지
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• 제28권4호
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• pp.356-378
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• 1993

본 논문은 도시산업구조의 경쟁력과 특화도, 그리고 그것의 변화특성에 관한 연구이다. 사례지역은 미국 Arizona의 42개 도시로서, 1970년부터 1990년까지의 9개 산업부 문을 대상으로 분석하였다. 본 언구에서 설정된 가설은 다음과 같다. (1) 1차 산업부문에 특 화된 도시들은 쇠퇴하기 쉬운 경향이 있다. (2) 도시의 규모는 산업의 다변화와 밀접한 관련 이 있다. 즉 도시규모가 클수록 산업 구성에 있어서 다변화되는 경향이 있다. (3) 대도시까 지의 거리는 도시산업의 다변화와 무관하다. (4) 도시들은 시간이 경과되면서 대체로 더욱 다변화되며, 그래서 도시특성이 상호간에 더욱 유사해진다. 이러한 가설들을 검증하기 위해 서 도시산업구성에 대한 클러스터분석(cluster analysis)을 통해서 1970년부터 1980년, 그리 고 1990년까지의 도시기능의 변화특성을 살펴보았고 도시기능과 산업구성상의 경쟁력이 관 계가 있음이 Arcelus가 변형한 변화, 할당모형의 분석을 통해서 확인되었다. 즉 1차산업(농 업, 광업)에 특화된 도시들은 경쟁력이 약해서 성장이 지체되는 경향이 나타났다. 특화계수 (coefficient of specialization)의 상관분석을 통해서는 산업특화 수준이 인구와 고용을 지표 로 한 도시규모와 밀접하게 연관이 되어 있어서 큰 도시일수록 산업구성이 다변화되는 것이 확인되었다. 그러나 대도시까지의 거리와 도시의 특화정도의 상관성은 약하게 나타났다. 1970년부터 1990년까지의 특화계수의 변화를 살펴보면, 시간이 경과되면서 도시들은 더욱 다변화하는 경향이 확인되었고, 이것은 결국 도시상호간의 산업구조상의 차별성을 약화시켜 서 서로 수렴되는 특성으로 나타난다.

• Mycobiology
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• 제49권4호
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• pp.376-384
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• 2021

Agaricus bisporus is a popular edible mushroom that is cultivated worldwide. Due to its secondary homothallic nature, cultivated A. bisporus strains have low genetic diversity, and breeding novel strains is challenging. The aim of this study was to investigate the genetic diversity and population structure of globally collected A. bisporus strains using simple sequence repeat (SSR) markers. Agaricus bisporus strains were divided based on genetic distance-based groups and model-based subpopulations. The major allele frequency (MAF), number of genotypes (NG), number of alleles (NA), observed heterozygosity (HO), expected heterozygosity (HE), and polymorphic information content (PIC) were calculated, and genetic distance, population structure, genetic differentiation, and Hardy-Weinberg equilibrium (HWE) were assessed. Strains were divided into two groups by distance-based analysis and into three subpopulations by model-based analysis. Strains in subpopulations POP A and POP B were included in Group I, and strains in subpopulation POP C were included in Group II. Genetic differentiation between strains was 99%. Marker AB-gSSR-1057 in Group II and subpopulation POP C was confirmed to be in HWE. These results will enhance A. bisporus breeding programs and support the protection of genetic resources.

• 품질경영학회지
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• 제23권1호
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• pp.95-105
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• 1995

The error structure of nonlinearized technological growth models, such as, the Pearl curve, the Gompertz curve and the Wei bull growth curve, has zero mean and a constant variance over time. Transformed models, however, like the linearized Fisher-Pry model. the linearized Gompertz growth curve, and the linearized Weibull growth curve have increasing variance from t = 0 to the inflection point.

• 대한산업공학회지
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• 제22권2호
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• pp.277-302
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• 1996

The overall performance of BISDN depends significantly on the interconnection network or the switch fabric. Hence, it is extremely important to evaluate the performance of the network or the fabric. The well developed performance models also provide insight into the factors that determine design tradeoffs as well as quantitative estimates of their importance. The objective of this paper is to investigate and critically compare all the developed performance analysis models of FPS according to internal switch fabric structure, traffic assumptions, performance measures, methodologies, etc. FPSs are described according to their internal fabric structure. Brief history of FPS performance analysis is mentioned and performance analysis modeling is discussed.

• 산업기술연구
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• 제31권A호
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• pp.27-31
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• 2011

In many industrial experiments, some practical constraints often force factors in an experiment to be much harder to change than others. Such an experiment involves randomization restrictions and it can be thought of as split-plot experiment. This paper investigates the path of steepest ascent/descent within a split-plot structure. A method is proposed for calculating the coordinates along the path.

• 노동경제논집
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• 제35권1호
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• pp.55-88
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• 2012

이 논문은 각 산업의 인력고령화 실태를 살펴보고 산업구조의 변화가 고령자에 대한 노동시장 수요 및 고령자의 고용안정성에 미친 영향을 분석하였다. 2001~2010년 사이 고령근로자를 많이 고용한 산업의 고용규모는 상대적으로 축소되어 고령근로자에 대한 노동시장의 상대적인 수요가 감소하였다. 또한 2001~2010년 발생한 산업구조의 변화는 고령근로자의 고용안정성을 낮추는 방향으로 이루어졌다. 논문의 결과는 고령인력의 고용을 증진시키고자 하는 정책을 수립하는 데 있어서 고령자의 노동시장 여건이 전반적으로 호의적이지 못하다는 점과 각 산업의 고령자 고용여건이 매우 이질적이라는 사실을 고려할 필요가 있다는 것을 시사한다.

• Industrial Engineering and Management Systems
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• 제10권2호
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• pp.161-169
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• 2011

In seeking further efficiency in production preparation, it is common to examine assembly sequences using digital manufacturing. The assembly sequences affect the product evaluation, so it is necessary to test several assembly sequences before actual production. However, because selection and testing of assembly sequences depends on the operator's personal experience and intuition, only a small number of assembly sequences are actually tested. Nevertheless, there is a systematic method for generating assembly sequences using a contact-related figure. However, the larger the number of parts, the larger the number of assembly sequences geometric becomes. The purpose of this study is to establish a systematic method of generating efficient assembly sequences regardless of the number of parts. To generate such assembly sequences selectively, a "Tournament Tree," which shows the structure of an assembly sequence, is formulated. Applying the method to assembly sequences of a water valve, good assembly sequences with the same structure as the Tournament Tree are identified. The structure of such a Tournament Tree tends to have fewer steps than the others. As a test, the structure is then applied for a drum cartridge with 38 parts. In all the assembly sequences generated from the contact-related figures, the best assembly sequence is generated by using the Tournament Tree.

• 산업기술연구
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• 제20권A호
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• pp.295-301
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• 2000

Various nondestructive prospecting method were applied to detect the flaws of concrete structure, but the satisfactory result could not be obtained, yet. Fracture and cavities existing concrete structure will have a bad effect on physical and mechanical characteristic of concrete. This study deal with detection of flaws using seismic first arrival and various inversion method in theoretical model. And ultrasonic seismic method is tried to experimental model to detect fracture and cavity.

• 산업기술연구
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• 제27권B호
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• pp.153-160
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• 2007

In this paper, the exact analysis of the parallel coupled line with open stub is presented. This structure shows LPF characteristics with broad stopband and sharp skirt characteristics. We derived the exact Z-matrix expression of the structure. In order to show the validation of the expression we designed $3^{th}$ order Chebyshev LPF using the structure. The simulated data excellently agreed with the predicted values by the calculation using the derived expression.