• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.612-615
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• 2002

The objective of this study is to develop an integrated process planning system which can flexibly cope with the status changes in a shop floor by utilizing the concept of Non-Linear and Closed-Loop Process Planning(NCPP). In this paper, Genetic Algorithm(GA) is employed in order to quickly generate feasible setup sequences for minimizing the makespan and tardiness under an NCPP. The genetic algorithm developed in this study for getting the machine load utilizes differentiated mutation rate and method in order to increase the chance to avoid a local optimum and to reach a global optimum. Also, it adopts a double gene structure for the sake of convenient modeling of the shop floor. The last step in this system is a simulation process which selects a proper process plan among alternative process plans.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.531-531
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• 2012

So many groups have been researching the green quantum dots such as InP, InP/ZnS for overcoming the semiconductor nanoparticles composed with heavy metals like as Cd and Pb so on. In spite of much effort to keep up CdSe quantum dots, it does not reach the good properties compared with CdSe/ZnS quantum dots. This quantum dot has improved its properties through the generation of core/shell CdSe/ZnS structure or core/multi-shell structures like as CdSe/CdS/ZnS and CdSe/CdS/ CdZnS/ZnS. In this research, we try to synthesize the InP multi-shell structure by the successiveion layer absorption reaction (SILAR) in the one pot. The synthesized multi-shell structure has improved quantum yield and photo-stability. To generate white light, highly luminescent InP multi-shell quantum dots were mixed with yellow phosphor and integrated on the blue LED chip. This InP multi-shell improved red region of the LEDs and generated high CRI.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.17-22
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• 2000

The transient process simplified by the 1-D stretched laminar flame formed at the fuel-oxidizer interface was investigated using the coherent flame sheet model. Under the combustion environment of high temperatures and pressures the results show that the time required to reach the steady state was relatively short compared to the reverse of strain rate. Hence the employment of the tabulation of precalculated steady-flame results in the calculation of turbulent diffusion flames using the coherent flame sheet model is concluded valid, Also upstream temperatures were found to have only a minor effect on the nondimensional flame temperature and nondimensional fuel even through the letter is sensitive to pressure changes.

• The Journal of Korea Robotics Society
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• v.3 no.2
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• pp.106-111
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• 2008

This paper presents a decentralized coordination for a small-scale mobile robot teams performing a task through cooperation. Robot teams are required to generate and maintain various geometric patterns adapting to an environment and/or a task in many cooperative applications. In particular, all robots must continue to strive toward achieving the team's mission even if some members fail to perform their role. Toward this end, given the number of robots in a team, an effective coordination is investigated for decentralized formation control strategies. Specifically, all members are required first to reach agreement on their coordinate system and have an identifier (ID) for role assignment in a self-organizing way. Then, employing IDs on individual robots within a common coordinate system, a decentralized neighbor-referenced formation control is realized to generate, keep, and switch between different geometric shapes. This approach is verified using an in-house simulator and physical mobile robots. We detail and evaluate the formation control approach, whose common features include self-organization, robustness, and flexibility.

• Journal of the Korean Society of Food Culture
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• v.9 no.2
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• pp.149-157
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• 1994

Hospitalized patients' perceptions of the quality of hospital foodservice and their importance were surveyed through questionnaires by 820(men 435, women 385) hospitalized patients in Seoul. The results are as follows: Most respondents agreed with the following foodservice characteristics that meals arrived exactly the same time every day(74.6%), cleanliness of dishes(64.9%), employees leave food within reach(60.2%), and employees who bring meals are cheerful(58.7%). Only 34.2% of respondents agreed to variety of menu; 12.9% of respondents viewed these foodservice characteristics as important in selecting a hospital; cleanliness of dishes(66.4%), variety of menu(55.0%), and varying food item combination(45.9%) were considered important by respondents; appetite, mood, and atmosphere of ward were positively correlated(p<0.001) with rating of the foodservice characteristics, but length of hospitalization was negatively correlated(p<0.001) with them; familiarity with cooking method, varying food item combination, cleanliness of the dishes, and foodservice employees' pleasant greeting were positively correlated(p<0.001) with rating of the taste, nutrition, and fresshness of the food characteristics.

• Korean Journal of Animal Reproduction
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• v.13 no.3
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• pp.127-133
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• 1989

This study was undertaken to understand development stage of ovary and changes of hormones concentration from February to May in the Israeli carp, Cyprinus carpio. The results obtained in these experiments are as follows ; 1. Serum LH levels began to increase sharphy in March, coinciding with the onset of rapid ovarian development. 2. LH levels were well correlated with changes in gonadosomatic index. 3. Dramatic increase in gonadosomatic index occurred during the months of March. 4. Ripe stage(Stage Ⅴ) rapidly increase in March. 5. Early perinucleolus oocyte radpily develop into late perinucleolus oocytes in March. 6. The vitellogenic phase begins as these late perinucleolus oocytes become transformed into early maturing oocytes through the accumulation of yolk. 7. The cytoplasm completely fills with yolk as oocytes reach the late maturing stage. 8. Changes in the microscopic appearances of the ovaries were well correlated with changes in both gonadosomatic index and macroscopic appearance. 9. It is concluded from these observations that LH plays a major role in sexual maturation of the Israeli carp.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.541-548
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• 2002

Membrane, cable structure and membrane-cable structural system are more lighter than another common structural system, and these are able to be effectively build Lip spatial structures using axial stiffness. However when the load reach at critical load level, it might be happened snap-through or bifurcation according to the structure's shape, and these collapse mechanism should be very important in the design of structures. So, In this paper we study static instability of Zetlin-type cable dome, one of the hybrid cable dome. Moreover, as the unstable behavior of shell structures are very sensitive to the initial condition, we seek to find the effect of initial condition.

• International Journal of High-Rise Buildings
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• v.6 no.1
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• pp.21-31
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• 2017

Jeddah Tower will be the first man-made structure to reach a kilometer in height upon its completion in 2019. From conception, it was clear that an all-concrete superstructure would present many advantages for a building of such unprecedented height and slenderness. An all-concrete structure, however, did present many challenges that needed to be addressed in the system arrangement and through comprehensive analysis and design, among them vertical shortening effects due to the time-dependent creep and shrinkage of concrete. This paper outlines and presents the engineering solutions developed by the authors regarding this complex concrete material phenomenon, while addressing the construction and regional challenges associated with realizing a concrete tower of this unprecedented scale.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.124-133
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• 2005

The purpose of this study is to analyze the effectiveness of process approach for business performance of a company certified with ISO 9000 : 2000 quality management system. The result of this empirical research were identified as follows. Documentation and an intelligence process appeared with a preference matter in an influence to reach to a business performance of a company through the organization which established a process approach. It reveals that the process approach of quality management system might affect positively for customer satisfaction, product qualify, financial results and cost reduction.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.124-126
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• 1997

A number of electromagnetic devices periodically driven by solid-state switches have been analyzed with time-stepping finite element method, which requires much time to reach a steady state. The sensitivity analysis which have been used for the shape design is employed for an efficient calculation of linear magnetodynamics with nonsinusoidal driving sources. The high-order frequency sensitivity from the harmonic finite element formulation is used along with Fourier transform and Taylor series expansion. The algorithm is validated through a numerical example of a single-phase transformer driven by a trapezoidal voltage source.