• Journal of the Korean Society of Radiology
• /
• v.15 no.4
• /
• pp.415-427
• /
• 2021

Korea Institute of Radiological and Medical Sciences has provided various beam irradiation services to researchers using a 50 MeV cyclotron beam line. In particular, since the neutron beam service uses the nuclear reaction between protons and beryllium, the possibility of activation of the irradiated sample increases by using a high current. In this study, MCNP 6.2 and FISPACT-II 4.0 were used to evaluate the possible activation during the 35 MeV 20 ㎂ neutron beam service, which is preferred by the researchers. As a result of the calculation, if the iron, copper, and tungsten samples were irradiated for more than 1 hour, long-lived radioisotopes were produced and their radioactivity exceeded the standard level for self-disposal. Under the conditions of 2 hours of daily irradiation, no activation occurred in the building materials, and the internal exposure of workers due to air activation inside the irradiation room was very insignificant. And when this air was discharged to environment, the radioactivity including this air was also satisfied the emission standard.

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.04a
• /
• pp.847-849
• /
• 2002

인공면역시스템에서 중요한 특징중의 하나는 지속적으로 변화하는 환경에서 자기(self)의 유동적인 패턴을 동적으로 학습하고 비자기(non-self)에 대한 새로운 패턴을 예측하는데 있다. 본 논문은 자기적 용(self-adaptation)의 인공면역체계 특성을 기반으로하여 설계된 dynamics(동적 클론선택 알고리즘, dynamic clonal selection algorithm)의 역할을 논한다. 시스템의 세가지 중요한 변수인 자기내성 기간(Tolerisation Period). 연역 반응 임계값(activation threshold). 수명(life span)에 따라 변화하는 dynamics의 성능을 네트워크 침입에서 흔히 발견되는 시나리오를 모의실험하여 평가한다

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.27 no.12
• /
• pp.1841-1851
• /
• 1990

Self-aligned gate GaAs MESFETs using ion beam deposited tungsten applicable to GaAs LSI fabrication process have been fabricated. Silicon implanted samples were annealed using isothermla two step RTA process and conventional one step RTA process. The electrical and physicla characteristics of annealed samples were investigated using Hall and I-V measurements. As results of measurements, activation characteristics of the isothermal two step RTA process are better than those of one step annealed ones. Using the developed processes, GaAs SAFETs (Self-Aligned Gate FET) have been fabricated and electdrical characteirstics are measured. As results, subthreshold currents of SAGFETs are 6x10**-10 A/\ulcorner, that is compatible to conventional MESFET, maximum transconductances of 0.75\ulcorner gate MESFET using one step RTA process and 2\ulcorner gate MESFET using isothermal two step RTA process are 18 mS/mm, 41 mS/mm respectively.

• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.2
• /
• pp.189-199
• /
• 1999

This paper presents an optimization algorithm for a stable Self Dynamic Neural Network(SDNN) using genetic algorithm. Optimized SDNN is applied to a problem of controlling nonlinear dynamical systems. SDNN is dynamic mapping and is better suited for dynamical systems than static forward neural network. The real-time implementation is very important, and thus the neuro controller also needs to be designed such that it converges with a relatively small number of training cycles. SDW has considerably fewer weights than DNN. Since there is no interlink among the hidden layer. The object of proposed algorithm is that the number of self dynamic neuron node and the gradient of activation functions are simultaneously optimized by genetic algorithms. To guarantee convergence, an analytic method based on the Lyapunov function is used to find a stable learning for the SDNN. The ability and effectiveness of identifying and controlling a nonlinear dynamic system using the proposed optimized SDNN considering stability is demonstrated by case studies.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.7
• /
• pp.88-93
• /
• 1998

For the self-aligned AlGaAs/GaAs HBTs, the surface states at the interface between the extrinsic base surface and the passivation nitride is a major cause of degradation of dc characteristics. In this paper the degradation mechanisms of self-aligned AlGaAs/GaAs HBT were analyzed, and GaAs HBTs, which employed an InGaP ledge emitter structure formed by the nonself-aligned process to cover the surface of the extrinsic base and reduce the surface states, produced high reliability. Accoridng to the acceleration lifetime test, the nonself-aligned InGaP/GaAs HBTs produced very reliable dc characteristics comparing with the self-aligned AlGaAs/GaAs HBTs. The activation energy was 1.97eV and MTTF $4.8{\times}10^{8}$ hrs at $140^{\circ}C$ which satisfied the MIL standard.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05a
• /
• pp.197-201
• /
• 1996

In the detail reaction-rate measurements in a critical assembly using the foil activation method, the measured activations of detector foils have inevitably errors caused by detector foil self-shielding effect. If neutron flux could be approximated to Westcott flux: i.e. well thermalized Maxwellian distribution, these activations of detector foil could be corrected to represent the unperturbated flux at any detected position in the cell with using Westcott option and reaction-rate option of the lattice code, WIMS-AECL. These calculated detector material self-shielding correction factors of the tested fuel, CANFLEX provided much information about neutron spectrum of test lattice cell as well as the correction factors themselves. The results could be verified by another lattice calculations.

• Journal of muscle and joint health
• /
• v.22 no.3
• /
• pp.245-257
• /
• 2015

Purpose: The purpose of this study was to apply intervention mapping (IM) to develop a community-based disease self-management support program for patients with osteoarthritis. Methods: IM was applied as follows: i) a needs assessment has been carried out by a literature review, survey and interview with osteoarthritis patients; ii) on the basis of the needs assessment, identification of expected outcomes and change objectives for the target population; iii) selection of theory-based methods and practical applications to influence self-management and the determinants of behavior; iv) design of the intervention by developing activities and materials such as osteoarthritis self-management guide and smart patient pocket book. The activities were integrated into an existing healthcare activities; v) implementation and evaluation plan has been developed. Results: The program is aimed at improving health status through activating patients by a patient-centered and tailored intervention for patients with osteoarthritis; consists of 8 sessions with coaching and cognitive emotional psychological skills; includes smart patient, communication, osteoarthritis, medication adherence, pain control, depressive mood control, physical activity and healthy diet. Conclusion: The IM is a systematic and feasible method for developing the program. The next step is to evaluate the impact of the intervention on activation, and health status.

• Journal of Engineering Education Research
• /
• v.18 no.1
• /
• pp.54-60
• /
• 2015

The purposes of the study are to investigate the effects on academic of the self-directed learning and in-depth interviewing program in engineering underachieved students. 17 students participated in program and the grade points average(GPA) of participants are less than 2.5. First, we focus on the change of academic achievement after the self-directed learning and in-depth interviewing program. According to results, it is very effective not only in improving academic achievement of the participation subject but also in increasing GPA. Second, the pre-survey and the post-survey were conducted to the participants. We found some facts from the difference between the pre and post surveys. The expectation and satisfaction about learning have improved after self-directed learning, and the participants' recognition showed the meaningful change in important factors about learning.

• Elastomers and Composites
• /
• v.46 no.3
• /
• pp.245-250
• /
• 2011

The self diffusions and hole volumes of amorphous region of poly(acrylonitrile)-poly(vinyl chloride) fibers were investigated by experiments of stress relaxation. The experiments of stress relaxation were carried out using the tensile tester with the solvent chamber. The flow parameters of filament fibers were obtained by applying the experimental stress relaxation curves to the theoretical equation of stress relaxation. From the flow parameters, the hole volumes, self diffusions, viscosities and thermodynamic parameters of solid polymers were calculated. It was observed that the flow parameters of these samples are directly related to the hole volumes, self diffusions and flow activation energies of flow segments.

• Journal of Family Resource Management and Policy Review
• /
• v.22 no.2
• /
• pp.1-24
• /
• 2018

Communal places for parents to take child-care are very important in activating cooperative child-care(CCC). Therefore, Jeju Special Self-Governing Province has been operating Cooperative-Childcare-Places(CCPs) since 2016. This study analyzed the operational status of the CCPs and presented the model type to provide data for the activation of CCC. Qualitative analyses were applied to the results of interviews with 10 staff members. The common task they considered difficult was recruitment, and there was a big difference in the operation of the regular program depending on the competence of the staff in charge. The lack of support systems, such as education and consulting, has made it difficult for the staff to do their work. Additionly, four models of CCPs were found, a resident self-governing type, a workplace type, an institutional type, and a rural complex type. In conclusion, CCP spaces should be planned and facilities created with a focus on the needs of child-care activities. Second, the role of staff in helping to organize the parents' self-governing committee is crucial. Third, it needs to establish a support system to strengthen the capacity of the staff members.