神學과 體驗

G. 오콜린즈(Gerald O’Collins, S.J.),林琪石(번역자) 광주가톨릭대학교 신학연구소 1979 神學展望 Vol.- No.47

Equivalent Material Properties of Thin and Thick Perforated Plate by FEM simulation

Collins Owino JUMA,Ihn NAMGUNG 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

Perforated plates are used for the steam generator tube sheet and the Reactor Vessel Closure Head in the Nuclear Power Plant. The structural integrity of these perforated structures is vital to the operation and safety of the Nuclear Power plant. ASME code addresses the analysis of perforated plates in Section III, Appendix A-8000, with triangular perforation pattern. This paper investigates the equivalent material properties by FEM methodology. Simulation of both thin and thick perforated plates and try to re-assess ASME Section III Appendix A-8000 curve. The isotropic material properties of the perforated plate were replaced with anisotropic material properties of the equivalent solid plate and subjected to same loading and boundary conditions. The difference between the deformation of the perforated and equivalent solid plate was optimized for convergence by varying the effective elastic constants. Curves of the effective elastic constants vs ligament efficiency were generated. The equivalent material property curves obtained using FEM methodology were in good agreement with the design curve provided in ASME Section. III Appendix A-8000.

The Effect of Light on Champagne Yeast Cell Growth and Ethanol Production Under Variable pH Conditions

Collins, Paul C.,Schnelle, Karl B.,Malaney, Jr.George W.,Tanner, Robert D. The Korean Society for Biotechnology and Bioengine 1991 KSBB Journal Vol.6 No.2

The effect of wtlitc light on unaeraten growth of Baker's yeast and the accompanying ethanol production has been studied in a batch process at 27$^{\circ}C$. Over the 80-hour period of the Champagne yeast process without pH control, the cull growth was inhibited by the fluorescent light. Another observed difference between the runs is that the drop and subsequent rise in redox potential occurred much sooner in the fermentation with light than in the fermentation without light. This preliminary study indicated that ethanol production could be enhanced by light as the cell concentration is repressed. The possible pathway, shift of the sugar substrate toward ethanol and away from cells was manifested by another difference as well. As observed under the microscope, many of the yeast cells grown under light budded without dividing by the normal fission process as they did in the dark. Furthermore, the undivided and branched (light grown) cell did not agglutinate at the end of the fermentation process as did the distinct spherical (dark grown) cells.

Review : Agricultural Process and Food Engineering ; Current State of Postharvest Fruit and Vegetable Management in East Africa

( Collins Wakholi ),( Byoungkwan Cho ),( Changyeun Mo ),( Moon S. Kim ) 한국농업기계학회 2015 바이오시스템공학 Vol.40 No.3

Purpose: Fruit and vegetable production is a fast-growing sector in East Africa, and it bears considerable local and international market potential. In an effort to analyze the challenges within this sector and suggest possible solutions, this study reviews the postharvest handling technologies commonly used with fruits and vegetables in East Africa. Methods: During the course of this study, small-scale farmers were identified as the most prominent producers of fruit and vegetable crops in the region. Results: We found that many of these small-scale farmers employed relative simple and inexpensive techniques in handling their limited volumes of produce. Several factors could be addressed to reduce postharvest losses, including weak policies, inferior infrastructure, and poor market strategies. However, the lack of basic knowledge (including demographic, scientific, and economic knowledge) among the stakeholders (e.g., researchers, farmers, governments, nongovernment organizations, and merchants) on how to develop, implement, use, and sustain the recommended handling technologies is probably the most problematic. Conclusions: We recommend that high priority be placed on closing the knowledge gap, which could enhance the efforts of all the stakeholders to address and reduce postharvest losses.

Assessment of Equivalent Elastic Modulus of Perforated Spherical Plates

collins juma,남궁인 한국압력기기공학회 2019 한국압력기기공학회 논문집 Vol.15 No.1

Perforated plates are used for the steam generator tube-sheet and the Reactor Vessel Closure Head in the Nuclear Power Plant. The ASME code, Section III Appendix A-8000, addresses the analysis of perforated plates, however, this analysis is only limited to the flat plate with a triangular perforation pattern. Based on the concept of the effective elastic constants, simulation of flat and spherical perforated plates and their equivalent solid plates were carried out using Finite Element Analysis (FEA). The isotropic material properties of the perforated plate were replaced with anisotropic material properties of the equivalent solid plate and subjected to the same loading conditions. The generated curves of effective elastic constants vs ligament efficiency for the flat perforated plate were in agreement with the design curve provided by ASME code. With this result, a plate with spherical curvature having perforations can be conveniently analyzed with equivalent elastic modulus and equivalent Poisson’s ratio.

CORPOREAL LABOR AT THE VIRTUAL LIBRARY : INFORMATION, TRANSPARENCY AND INEQUALITY AT THE LIBRARY OF CONGRESS

Collins, Samuel Gerald 한국아메리카학회 1998 美國學論集 Vol.30 No.2

Determination of Viability of Seedless Watermelon (citrullus lanatus) Seeds Using Hyperspectral Imaging and Chemometrics

( Collins Wakholi ),( Byoung-kwan Cho ) 한국농업기계학회 2017 한국농업기계학회 학술발표논문집 Vol.22 No.2

Hyperspectral imaging (HSI) has emerged as a powerful technique in non-destructive quality and safety inspection in the food industry. This is attributed to its ability to simultaneously detect the composition (chemical, structural and functional information) and distribution of particular traits in a given sample. Hyperspectral imaging (HSI) technology has been successfully employed in the non-destructive determination of internal quality parameters of seeds with a promise of revolutionizing industrial sorting applications. Despite the limitations, this study focuses on employing short wave-infrared (SWIR) HSI to predict the true viability of seedless water melon (citrullus lanatus) seeds. For this study, data from 1248 damage-free seeds were taken using a SWIR HSI camera (wave range 1000~2500 nm). Afterwards, the seeds were subjected to germination tests to determine their real viability. The data were modeled using multivariate data analysis methods (partial-least square discriminant analysis, PLS-DA and support vector machines, SVM) to optimally discriminate viable from non-viable seeds. Model building was done using 70% of the data, the rest were used for validation. The PLS-DA model was able to achieve the best accuracy of 74% and 72% in calibration and validation respectively. The low accuracy achieved was probably due to the complexity of modeling the natural causes of loss of seed viability or even due to the thick seed coat (deters spectral signal penetration). The future of this research will focus on improving classification accuracy and implementing the resultant model to a real-time, high-speed sorting system based on HSI detection technology.

신앙적 체험과 심리학의 관계

Collins, Gary 총신대학부설 기독교교육연구소 1991 기독교교육연구 Vol.2 No.1

Development of an Online measurement of corn seed viability using hyperspectral imaging

( Collins Wakholi ),( Youngwook Seo ),( Byoung-kwan Cho ) 한국농업기계학회 2016 한국농업기계학회 학술발표논문집 Vol.21 No.2

The ability to classify seeds according to their respective traits like viability, variety etc. is key to regulation and ensuring seed quality and purity. Since the mass inception of genetically modified (GM) seeds to the market, many undesirable effects have been observed and are able to pose danger to the natural ecosystem and to humans at large. On top of the undesirable effects, there is a need to keep the natural gene pool as pure as possible from mixing with GM genes thus calling for careful caution during the handling of GM organisms. Currently many regulations have been imposed on the trade and import of GM seeds. In some societies for instance, the imported GM seeds have to be either killed or traded under very careful certification conditions. Clearly, there is a need to develop cutting edge technology to detect Viable GM seeds before import or trade. The main purpose of this research was to develop a working online sorting system based on Short Wave Infrared (SWIR) hyperspectral imaging (HSI) that is able to detect and sort GM corn seeds according their viability. In this study, hyperspectral image data from 600 corn seeds (50% microwave treated, 50% as control) was collected, analyzed and used to build classification models to classify between treated (non-viable) and non-treated (control/viable) corn groups. Three classification models were tested which included Partial Least Squares-Discriminant Analysis (PLS-DA), Support Vector Machines (SVM) and Linear Discriminant Analysis (LDA). The PLS-DA model coupled with some image processing tools (2-D median filter and morphological operations) performed the best and was applied to the online sorting system and tested its performance at different conveyor belt speeds until optimum. The overall system classification accuracy from the online tests was found to be 84% and 81% for white and purple corn respectively at conveyor belt speed of about 72 mm/s. The overall system accuracy was found to be lower than that produced from the offline spectral analysis possibly due to effects like ambient temperature, electronic noise, test sample dissimilarity, etc. The results show that the hyperspectral based online sorting prototype is able to be used for non-destructive real-time inspection of corn seed viability which could be faster and cheaper alternative to the conventional measurement methods which are expensive, time consuming and representative.

Comparison between Tetrazolium and Germination Test Results for Melon Seed Viability Determination using Hyperspectral Imaging

( Collins Wakholi ),( Byoung-kwan Cho ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Tetrazolium (TZ) test is one of the most reliable and widely used method in research to determine seed viability. The TZ test is able approximate seed viability through determining whether a seed’s tissue is still biochemically active or not. Despite the accurate prediction of viability by germination tests, the TZ test is preferred because it is relatively quick compared to germination tests that take anywhere between days to weeks to acquire results. The objective of this study was to compare the TZ test with germination tests (proved to give a realistic picture of seed viability) results using Short wave infrared, SWIR Hyperspectral imaging, HIS data and multivariate data analysis. For this study, damage-free melon (cucumis melo) seeds were used and were randomly divided into two groups of 1000 seeds each. Hyperspectral imaging data of both groups were collected using the same settings and under same environment. One group was subjected to germination tests while the other to TZ test to determine the viability of the seeds. The performance of the multivariate classification models achieved based on germination tests and TZ test results were compared. A clear difference in the classification model performances for germination and TZ test based models were observed. The results of this study serve as a key foundation in the development of a real-time sorting system based on HSI for melon seeds.