• Nuclear Engineering and Technology
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• v.22 no.4
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• pp.337-350
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• 1990

A post-irradiation annealing study was conducted with use of reactor pressure vessel(RPV) steel A533B Cl.1 base metal irradiated to a dose of 4.84$\times$10$^{18}$ n/$\textrm{cm}^2$ at about 38$0^{\circ}C$. Microhardness and positron annihilation (PA) methods were used to obtain better understanding of the recovery of radiation hardening. Isochronal anneal experiments indicated that two recovery processes occur during annealing of irradiated specimens. The first recovery process occurs in the temperature range of 280-3O5$^{\circ}C$, Michrohardness and positron annihilation (PA) methods were used to obtain better understanding of the recovery of radiation hardening. Isochronal anneal experiments indicated that two recovery processes occur during annealing of irradiated specimens. The first recovery process occurrs in the temperature range of 280-305$^{\circ}C$. The variations of Ip, Iw and R parameters indicated that the formation of vacancy clusters by vacancy agglomeration and the annihilation of monovacancies are the first recovery process. The second recovery process occurs in the range of 405-49$0^{\circ}C$ and positron annihilation parameters measured indicated that the dissolution of carbon atoms decorated around vacancy-type defects and possible precipitates, and the annihilation of monovacancies give rise to the second recovery process. It was further indicated that radiation anneal hardening (RAH) in the range of 305-405$^{\circ}C$ between the temperature ranges for the two processes occurs due to the formation of carbon-decorated vacancy clusters and precipitates. The activation energies, orders of reaction and other characteristics of recovery processes were determined by the Meechan-Brinkman method. The activation energy for the first recovery process was determined as 1.76 eV and that for the second recovery process as 2.00eV. These values are lower than those obtained by other workers. This difference may be attributed to the lower copper content of the RPV steel used in the present study. The order of reaction for the first recovery process was determined as 1.78, while that for the second recovery process as 1.67 Non-integer orders of reaction for recovery processes seem to be attributed to the fact that several mechanisms for the first order and the second order of reaction are compounded in one process. This result also supports for the above conclusions from measurements of PA parameters.

• 재활복지
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• v.14 no.3
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• pp.225-256
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• 2010

This study aims to provide the basic data of the rehabilitation program for the schoolchild with intellectual disability by designing new framework of the features of postural control for the schoolchild with intellectual disability. For this, the study investigated what sensations the schoolchild are using to maintain posture by selectively or synthetically applying vision, vestibular sensation and somato-sensation, and how the coordinative sensory system of the schoolchild is responding to any sway referenced sensory stimulus. The study intended to prove the limitation of motor system in estimating the postural stability by providing the cognitive motor task, and provided the features of postural control of the schoolchild with intellectual disability by measuring the onset times and orders of muscle contraction of neuron-muscle when there is a postural control taking place due to the exterior disturbance. Furthermore, by comparatively analyzing the difference between the normal schoolchild and the intellectually disabled schoolchild, this study provided an optimal direction for treatment planning when the rehabilitation program is applied in the postural control ability training program for the schoolchild with intellectual disability. Taking gender and age into consideration, 52 schoolchild including 26 normal schoolchild and 26 intellectually disabled schoolchild were selected. To measure the features of postural control, CTSIB test, and postural control strategy test were conducted. The result of experiment is as followed. First, the schoolchild with intellectual disability showed different feature in using sensory system to control posture. The normal schoolchild tended to depend on somato-sensory or vision, and showed a stable postural control toward a sway referenced stimulus on somato-sensory system. The schoolchild with intellectual disability tended to use somato-sensory or vision, and showed a very instable postural control toward a sway referenced vision or a sway referenced stimulus on somato-sensory system. In sensory analysis, the schoolchild with intellectual disability showed lower level of proficiency in somato-sensation percentile, vision percentile and vestibular sensation percentile compare to the normal schoolchild. Second, as for the onset times and orders of muscle contraction for strategies of postural control when there is an exterior physical stimulus, the schoolchild with intellectual disability showed a relatively delayed onset time of muscle control, and it was specially greater when the perturbation is from backward. As for the onset orders of muscle contraction, it started from muscles near coax then moved to the muscles near ankle joint, and the numbers and kinds of muscles involved were greater than the normal schoolchild. The normal schoolchild showed a fast muscle contracting reaction from every direction after the perturbation stimulus, and the contraction started from the muscles near the ankle joint and expanded to the muscles near coax. From the results of the experiments, the special feature of the postural control of the schoolchild with intellectual disability is that they have a higher dependence on vision in sensory system, and there was no appropriate integration of swayed sensation observed in upper level of central nerve system. In the motor system, the onset time of muscle contraction for postural control was delayed, and it proceeded in reversed order of the normal schoolchild. Therefore, when use the clinical physical therapy to improve the postural control ability, various sensations should be provided and should train the schoolchild to efficiently use the provided sensations and use the sensory experience recorded in upper level of central nerve system to improve postural control ability. At the same time, a treatment program that can improve the processing ability of central nerve system through meaningful activities with organizing and planning adapting reaction should be provided. Also, a proprioceptive motor control training program that can induce faster muscle contraction reaction and more efficient onset orders from muscularskeletal system is need to be provided as well.

• The Korean Society of Law and Medicine
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• v.24 no.4
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• pp.103-128
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• 2023

According to the current act of Decision-Marking in Life-Sustaining Medicine, the decision to withhold or discontinue life-sustaining treatment is primarily based on the wishes of a patient in the dying process. Decision-making regarding life-sustaining treatment for these patients is made by the patient, if he or she is conscious, directly expressing his/her intention for life-sustaining treatment in writing or verbally or by writing an advance medical directive and physician orders for life-sustaining treatment. It can be exercised. On the other hand, if the patient has not written an advance medical directive or physician orders for life-sustaining treatment, the patient's intention can be confirmed with a statement from the patient's family, or a decision to discontinue life-sustaining treatment can be made with the consent of all members of the patient's family. However, in the case of an unrelated patient who has no family or whose family is unknown, if an advance medical directive or physician orders for life-sustaining treatment are not written before hospitalization and a medical condition prevents the patient from expressing his or her opinion, the patient's will cannot be known and the patient cannot be informed. A situation arises where a decision must be made as to whether to continue or discontinue life-sustaining treatment. This study reviewed discussions and measures for unbefriended patients under the current law in order to suggest policy measures for deciding on life-sustaining treatment in the case of unbefriended patients. First, we looked at the application of the adult guardian system, but although an adult guardian can replace consent for medical treatment that infringes on the body, permission from the family court is required in cases where death may occur as a direct result of medical treatment. It cannot be said to be an appropriate solution for patients in the process of dying. Second, in accordance with Article 14 of the Life-Sustaining Treatment Decision Act, we looked at the deliberation of medical institution ethics committees on decisions to discontinue life-sustaining treatment for patients without family ties.Under the current law, the medical institution ethics committee cannot make decisions on discontinuation of life-sustaining treatment for unbefriended patients, so through revision, matters regarding decisions on discontinuation of life-sustaining treatment for unbefriended patients are reflected in Article 14 of the same Act or separate provisions for unbefriended patients are made. It is necessary to establish and amend new provisions. In addition, the medical institution ethics committee must make a decision on unbefriended patients, but if the medical institution cannot make such a decision, there is a need to revise the law so that the public ethics committee can make decisions, such as discontinuing life-sustaining treatment for unbefriended patients.

• Journal of the Korean Chemical Society
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• v.19 no.5
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• pp.339-342
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• 1975

The rates of consumption of iodine and gas evolution in hydrazine-iodine reaction in the presence of large excess of hydrazine have been studied in the pH range 0.5${\sim}$7. They are the same at very low pH and both increase to respective asymptotic values as pH is increased. The rate of iodine consumption is three orders of magnitude faster than the rate of gas evolution at higher pH. The results are explained by postulating that $N_2H_4$ but not protonated form reacts with iodine and an intermediate, probably $N_2H_2I_2$, is formed which decomposed by first order reaction of rate constant about 1.5${\times}10^{-3}sec^{-1}$ in neutral and weakly acidic solutions.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1783-1789
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• 2005

Modeling of a steam generator crevice in a nuclear power system needs to take into account both thermalhydraulic and chemical phenomena. As a first step towards developing a reliable model, a chemical equilibrium model was developed to predict chemical speciation in a magnetite-packed crevice by adopting the “tableau” method. The model was benchmarked with the available experimental data and the maximum deviation did not exceed two orders of magnitude. The developed model was applied to predict the chemical speciation in a magnetite-packed crevice. It was predicted that caustic environment was developed by the concentration of NaOH and the dissolution of magnetite. The model indicated that the dominant aqueous species of iron in the caustic crevice was $FeO_2\;^-$. The increase of electrochemical corrosion potential observed in the experiment was rationalized by the decrease of dissolved hydrogen concentration due to a boiling process. It was predicted that under the deaerated condition magnetite was oxidized to hematite.

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.407-412
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• 2006

Bioluminescence single-site immunometric assay for methamphetamine (MA) using the native aequorin, a photoprotein, as a signal generator was developed for the first time. MA is a potent sympathomimetic amine with stimulant effects on the central nervous system. MA abuse induces hallucinations and, thus, may cause a serious social problem. The single-site immunometric MA assay was optimized and its dose-response behavior was examined. The dose-response curve shows that the detection limit is 1.1 ${\times}$ $10^{-10}$ M and a dynamic range is four orders of magnitude with 15 $\mu$g/mL BSA-MA conjugate and 1.0 ${\times}$ $10^{-8}$ M anti-MA antibody-biotin conjugate. In order to evaluate this assay, the structurally similar compounds, amphetamine, ephedrine, norephedrine, benzphetamine and N-4-(aminobutyl)methamphetamine were examined for their crossreactivity. None of these five compounds showed any cross-reactivity. Additionally, an artificial urine solution spiked with MA was analyzed by the MA assay, and the result of the analysis demonstrated the usefulness of the present assay for the determination of MA in urine.

• Structural Engineering and Mechanics
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• v.63 no.6
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• pp.847-856
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• 2017

Excessive vibrations can occur in long-span structures such as floors or footbridges due to occupant?s daily activity like walking and cause a so-called vibration serviceability issue. Since 1970s, researchers have proposed many human walking load models, and some of them have even been adopted by major design guidelines. Despite their wide applications in structural vibration serviceability problems, differences between these models in predicting structural responses are not clear. This paper collects 19 popular walking load models and compares their effects on structure?s responses when subjected to the human walking loads. Model parameters are first compared among all these models including orders of components, dynamic load factors, phase angles and function forms. The responses of a single-degree-of-freedom system with various natural frequencies to the 19 load models are then calculated and compared in terms of peak values and root mean square values. Case studies on simulated structures and an existing long-span floor are further presented. Comparisons between predicted responses, guideline requirements and field measurements are conducted. All the results demonstrate that the differences among all the models are significant, indicating that in a practical design, choosing a proper walking load model is crucial for the structure?s vibration serviceability assessment.

• Phonetics and Speech Sciences
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• v.3 no.4
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• pp.95-102
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• 2011

The purpose of this study was to identify the characteristics of the phonological discrimination ability and phonological working memory of 10 typically developing children aged 4, and 10 other children with Specific Language Impairments whose language age is similar. In orders to compare their phonological discrimination ability among phonological awareness, discrimination tasks were conducted at the syllable and phoneme levels. Also, in order to compare their phonological working memory, the subjects repeated nonsense syllables. The research results may be summarized as follows: First, the children with Specific Language Impairments demonstrated a lower performance than the typically developing children in phonological discrimination ability at both syllable and phoneme levels, and the difference between the groups was statistically significant. Second, the children with Specific Language Impairments exhibited a lower phonological working memory performance in all syllables compared with normal children. Although there was no significant difference in 2 and 3 syllables, a significant difference appeared as the length of the syllables became longer from 4 to 6 syllables. It is deemed necessary to conduct research into qualitative and quantitative differences through an formal assessment of the phonological awareness and phonological working memory of children with Specific Language Impairments.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.156-162
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• 2005

In this paper, we study the mechanism of lead deformation by numerically simulating the stamping process by means of a commercial finite element code. It is very important to analyze effects that the lead shape makes on the lead deformation, because the lead shape is often modified in order to minimize the deformation or to increase the buckling critical load of the punch. Therefore the stamping process, first, numerically simulated by considering as a quasi-static problem. Second, the effect on the lead deformation due to the lead shape variation, a linear lead geometry and a bent lead, was numerically analyzed and discussed. Finally, the punching order was optimized fur multi-lead generating stamping process. The results show that the bent lead is little bit more shifted than the linear lead after the punching process. But the bent lead is vertically less deformed than the linear lead. The punching order to successively generate the lead is good to keep the lead space uniform. The results will be very effectively applied for the design of the blanking or punching dies in industry.

• International Commerce and Information Review
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• v.12 no.1
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• pp.35-54
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• 2010

This article explored the bank's responsibilities in electronic payment system between Korea and U.S.A. In order to complete my research object, I used Article 4A of the U.C.C. and EFTA of 1978 and by Electronic Financial Transaction Act of Korea as a analytic instruments. I also adapted America's various regulations to regulate concerned parties(banks). The system of this article is going to display as fellows; First, I presented recent trend and legal stabilities of electronic payment in this article. Second, I focuses on the allocation of risk of loss caused by ambiguous term in payment orders that do not express the subjective intention of the senders. I also did analyze the solution procession of error occurring in course of send of payment order. Third, In any action which involves a customers's liability for an unauthorized electronic fund transfer, the burden of proof is upon the financial institution to show that the electronic fund transfer was authorized. Forth, Customers have to report the error and unauthorized electronic fund transfer after awaring of it. Then bank will be liable for such a unauthorized electronic fund transfer. But If customer's failure to report, the bank has exemptions. Lastly, In order to prevent or detect the unauthorized electronic fund transfer, bank will agree with custom to establish a commercially reasonable security procedure, while bank has duties to notify in order to decrease the loss resulted from unauthorized payment order in korea law.