• Journal of Hydrogen and New Energy
• /
• v.33 no.3
• /
• pp.261-265
• /
• 2022

In this paper, comparative studies between Linde, Claude and advanced cycle for the liquefaction of nitrogen have been completed. PRO/II with PROVISION release 2021. 1 from AVEVA company (Cambridge, UK) was used, and Peng-Robinson equation of the state model with Twu's alpha function was selected for the modeling of the condensation of nitrogen. When using Claude liquefaction, we can reduce the total compression power by 49.25% for the comparison of Linde cycle. And finally, we could conclude that 90.41% of total compression power was saved when using an advanced cycle being compared to Linde liquefaction cycle.

• Journal of Hydrogen and New Energy
• /
• v.33 no.4
• /
• pp.446-450
• /
• 2022

In this paper, comparative studies between Linde-Hampson and Claude cycle for the liquefaction of oxygen have been completed. PRO/II with PROVISION release 2021. 1 from AVEVA company (Cambridge, UK) was used, and Peng-Robinson equation of the state model with Twu's alpha function was selected for the modeling of the condensation of oxygen. When using Claude liquefaction cycle, we could reduce the total compression power by 59.51% for the comparison of Linde-Hampson cycle.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.12
• /
• pp.775-780
• /
• 2008

A dynamic model to simulate LNG reliquefaction process has been developed. The model was applied to two candidate cycles for LNG reliquefaction process, which are Reverse Brayton and Claude cycles. The simulation was intended to simulate the pilot plant under construction for operation of the two cycles and evaluate their feasibility. According to the simulation results, both satisfy control requirements for safe operation of brazed aluminum plate-fin type heat exchangers. In view of energy consumption, the Reverse Brayton cycle is more efficient than the Claude cycle. The latter has an expansion valve in addition to the common facilities sharing with the Reverse Brayton cycle. The expansion valve is a main cause to the efficiency loss. It generates a significant amount of entropy associated with its throttling and increases circulation flow rates of the refrigerant and power consumption caused by its leaking resulting in lowered pressure ratio. It is concluded that the Reverse Brayton cycle is more efficient and simpler in control and construction than the Claude cycle.

• International Journal of Air-Conditioning and Refrigeration
• /
• v.17 no.4
• /
• pp.135-140
• /
• 2009

A dynamic model to simulate LNG reliquefaction process has been developed. The model was applied to two candidate cycles for LNG reliquefaction process, which are Reverse Brayton and Claude cycles. The simulation was intended to simulate the pilot plant under construction for operation of the two cycles and evaluate their feasibility. According to the simulation results, both satisfy control requirements for safe operation of brazed aluminum plate-fin type heat exchangers. In view of energy consumption, the Reverse Brayton cycle is more efficient than the Claude cycle. The latter has an expansion valve in addition to the common facilities sharing with the Reverse Brayton cycle. The expansion valve is a main cause to the efficiency loss. It generates a significant amount of entropy associated with its throttling and increases circulation flow rates of the refrigerant and power consumption caused by its leaking resulting in lowered pressure ratio. It is concluded that the Reverse Brayton cycle is more efficient and simpler in control and construction than the Claude cycle.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.6 no.2
• /
• pp.130-139
• /
• 1994

A cycle analysis was performed for 2-stage expansion Claude refrigerators by a numerical method. The refrigerators are under recent development such that the reciprocating expanders of Collins cycle are replaced by new turboexpanders. A computer simulation program was written to predict the coefficient of performance of the refrigerators for several input parameters. It was found out that there exist unique optimum values for the ratio of expanded mass through the turboexpanders to the total mass and for the intermediate pressure of the 2-stage expansion. The maximum coefficient of performance was about $5{\times}10^{-4}$ at the optimal operation.

• Structural Engineering and Mechanics
• /
• v.15 no.4
• /
• pp.437-449
• /
• 2003

The aim of this study is to develop an analytical model of a beam with open cracks and external strengthening which is able to predict its modal scheme components (natural frequencies and mode shapes). The model is valid as far as the excitation level is low enough not to activate non linear effects. The application field of the model are either the prediction of the efficiency of the reinforcement or the non destructive assessment of the structural properties. The degrees of freedom associated to the fault lips must be taken into account in order to introduce the effect of the external strengthening. In a first step, an analytical formulation of a beam with thin notches is proposed according to the references. The model is then extended to incorporate the strengthening consisting in a longitudinal stiffness applied in the vicinity of the cracks. In a second step, the analytical results are compared with these obtained from a finite element simulation.

• Steel and Composite Structures
• /
• v.3 no.1
• /
• pp.33-46
• /
• 2003

This study focuses on the influence of a composite external strengthening on the natural frequencies of a steel beam with open cracks. In a first step, the leading parameters associated with the effect of the composite strengthening are experimentally identified. An analytical model is developed in order to quantify the importance of the force transfer within the resin interface. In a second step, the analytical model of a cracked beam with composite external strengthening is compared to experiments.

• The Mathematical Education
• /
• v.63 no.3
• /
• pp.549-571
• /
• 2024

As digital·AI-based teaching and learning is emphasized, discussions on the educational use of generative AI are becoming more active. This study analyzed the mathematical performance of ChatGPT 4, Claude 3 Opus, and Gemini Advanced on solving examples and problems from five first-year high school math textbooks. As a result of examining the overall correct answer rate and characteristics of each skill for a total of 1,317 questions, ChatGPT 4 had the highest overall correct answer rate of 0.85, followed by Claude 3 Opus at 0.67, and Gemini Advanced at 0.42. By skills, all three models showed high correct answer rates in 'Find functions' and 'Prove', while relatively low correct answer rates in 'Explain' and 'Draw graphs'. In particular, in 'Count', ChatGPT 4 and Claude 3 Opus had a correct answer rate of 1.00, while Gemini Advanced was low at 0.56. Additionally, all models had difficulty in explaining using Venn diagrams and creating images. Based on the research results, teachers should identify the strengths and limitations of each AI model and use them appropriately in class. This study is significant in that it suggested the possibility of use in actual classes by analyzing the mathematical performance of generative AI. It also provided important implications for redefining the role of teachers in mathematics education in the era of artificial intelligence. Further research is needed to develop a cooperative educational model between generative AI and teachers and to study individualized learning plans using AI.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.4
• /
• pp.127-139
• /
• 2021

This study is intended to review the poetic directing created by the aesthetics of silence of Claude Régy, a French director who carries out playwriting in silence, departing from conventions through the concept of "potentiality" proposed by Giorgio Agamben, an italian philosopher. Claude Régy stated, "What's fundamentally important is not to say what you want to say." Thus he tries to create the stage of "silence" rendered in overly slow, excessively segmented dialogues while selecting restrained minimal means. Agamben makes Bartleby who "prefers not to" as a cardinal model of his perfect potentiality, asserting that the nature of potentiality is revealed in the pause of actuality. As in Agamben's philosophy, Claude Régy's directing is also the "pause" of words and actions. This silence is not a return to actuality but a creation of the moment at which "the invisible" become visible. The silence of words or the silence of an empty stage with dim lighting is viewed by Agamben as potentiality that has "underlying passivity" and is "hospitable to non-existnece". In this light, this study is to create another direction for the theater arts of our time and the 21^st century and to extend the horizon of new directional modes. It aldo reviews the concept of Agamben's "potentiality" that provides critical viewpoints to "the artist without content", works directed by Claude Régy who has created his own distinctive styles of direction with the aesthetics of "slowness" and "silence", L'intérieur by Maurice Maeterlinck and Quel'un va venir By Jon Fosse.

• The Journal of Internal Korean Medicine
• /
• v.42 no.5
• /
• pp.1054-1061
• /
• 2021

Objective: The aim of this study was to report the effect of Korean medicine treatment on Claude's syndrome with ataxia and diplopia. Methods: We applied electroacupuncture, scalp acupuncture, and physical therapy to the patient. Diplopia was assessed with the distance between two images of one object, and ataxia was assessed with the Korean Version of the Scale for the Assessment and Rating of Ataxia (K-SARA). Results: After 21 days of treatment, diplopia, abnormal extraocular movement, and ataxia were improved on the basis of the K-SARA score. Conclusion: This case demonstrates the effectiveness of Korean medicine treatment in improving the symptoms of Claude's syndrome.