• 한국식물학회:학술대회논문집
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• 한국식물학회 1993년도 제7회 식물생명공학 심포지움 식물 세포 분화의 분자적 접근 Seventh Symposium on Plant Biotechnology -Approach to Plant Cell Differentiation-
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• pp.1-36
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• 1993

It is possible to regenerate plants from calli, single cells and protoplasts of numerous species via organogenasis or embryogenesis in cell and tissue culture systems. Also such regeneration of plants can directly occur from cells of explants. However certain plant species has not been yet provided cultures suitable for plant regeneration from cells or tissues. For example, we have to confirm the regenerability of plant from cells before preparing transformed cells for application. Even more, it is very important to notice that regenerated plants in cell and tissue cultures often show structural abnormality. The mojority of those plants is functionally disordered and eventually cases degenerated. One of such examples is vitreous plants which are manifested mainly in the leaves and manifesteds to a lesser extent in the stems and roots. Regenerants in suspension cultures show more frequent vitrification than on gelled media so that relative humidity and water potential are the key factors involved in abnormal morphogenesis in vitro. The other is that somatic embryos formed in media containing BAP or high concentration of sucrose show frequently cotyledon aberrancy such as polycotyledon and born type cotyledon. The embryos with aberrant cotyledon of Codonopsis lanceolata could not germinate or regenerate into plants in many cases. In contrast, the polycotyledon embryos of Aralia cordata germinated in higher percentage than two cotyledonary embryos, but horn type cotyledonary embryos rarely germinated. The major cause of poor germination is the abnormal development of plumule apex meristem.

• Safety and Health at Work
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• 제12권3호
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• pp.351-358
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• 2021

Backgrounds: Irregular and unpredictable work schedules have become more common in most societies. The purpose of this study was to investigate the association between unpredictable work schedules and depressive symptoms in Korea. Methods: Data from 34,486 workers who participated in the Korean Working Condition Survey in 2017 were used. Unpredictable work schedules were measured by questions about the frequency of changes in work schedule and limited advanced notice. Depressive symptoms were assessed by a single item asking if the participants had depressive symptoms over the last 12 months. Multivariable-adjusted logistic regression analysis was used to calculate odds ratios (ORs) for high depressive symptoms. Results: The OR for depressive symptoms was significantly higher in the workers with unpredictable work schedules compared to those with predictable work schedules after controlling for age, sex, education, salary, marital status, occupation, contract period, full-time versus part-time, shift work, weekly working hours, and having a child under the age of 18 years (OR = 2.43, 95% confidence interval 1.93-3.07). Conclusion: Unpredictable work schedules were associated with depressive symptoms controlling for the other dimensions of precarious employment in a representative working population in Korea.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.265-271
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• 1992

It is the purpose of this paper to present a dialogical designing method for control system using a rough grasp of the unknown process property. We deal with a single-input single-output feedback control system with a fuzzy controller. The process property is roughly estimated by the step response, and the fuzzy controller is interactively modified according to the operator's requests. The modifying rules mainly derived from computer simulation are useful for almost every process, such as an unstable process and a non-minimum phase process. The fuzzy controller is tuned by taking notice of four characteristics of the step response: (1) rising time, (2) overshoot, (3) amplitude and (4) period of vibration. The tuning position of the controller is fourfold: (1) antecedent gain factor GE or GCE, (2) consequent gain factor GDU, (3) arrangement of the antecedent fuzzy labels and (4) arrangement of the control rules. The rules give an instance to the respective items of the controller in an effective order. The modified fuzzy PI controller realizes a good response of a stable process. However, because the GDU tuning becomes difficult for the unstable process, it is necessary to evaluate the stability of the process from the initial step response. The fuzzy PI controller is applied to the process whose initial step response converges with GDU tuning. The fuzzy PI controller with modified sampling time is applied to the process whose step response converges under the repeated application of the GDU tuning. The fuzzy PD controller is applied to the process whose step response never converges by the GDU tuning.

• Physical Therapy Rehabilitation Science
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• 제5권3호
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• pp.149-154
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• 2016

Objective: The arm swing is associated with gait ability in healthy young adults. The purpose of this study was to examine the effects of arm swing during gait in healthy young adults. Design: Cross-sectional study. Methods: Forty-five subjects without any orthopedic or neurological injuries participated in this study. All subjects performed all three conditions according to the arm swing type as follows: first procedure (condition 1), walking as usual without arm swing constraint; second procedure (condition 2), constraint of dominant arm swing walking as usual; third procedure (condition 3), constraint of both arm swing walking as usual. Gait parameters such as gait velocity, stride length, cadence, step time, single limb support, and double limb support were measured in all arm swing conditions performed randomly, with the mean value obtained from three measurements. A rest period of 5 minutes was given to prevent repetition of each condition and learning effect. All data was analyzed using repeated measures ANOVA to notice the changes between arm swing conditions. Results: Within walking conditions, significant difference of gait velocity, stride length, cadence, and double limb support was noticed (p<0.05), except step time and single limb support. Gait velocity and stride length were significant reduced, and in cadence and double limb support were increased (p<0.05). Condition 3 had the most significant decrease of gait ability compared with condition 1 (p<0.05). Conclusions: These finding suggested that constraint arm swing conditions reduced gait ability in healthy young adults. Also, these findings can be utilized as a reference to future studies that not only pelvic, knee and ankle, but also upper limb affect to gait ability.

• Journal of Radiation Protection and Research
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• 제41권2호
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• pp.81-86
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• 2016

Background: For positron emission tomography (PET) application, cadmium zinc telluride (CZT) has been investigated by several institutes to replace detectors from a conventional system using photomultipliers or Silicon-photomultipliers (SiPMs). The spatial and energy resolution in using CZT can be superior to current scintillator-based state-of-the-art PET detectors. CZT has been under development for several years at the Korea Atomic Energy Research Institute (KAERI) to provide a high performance gamma ray detection, which needs a single crystallinity, a good uniformity, a high stopping power, and a wide band gap. Materials and Methods: Before applying our own grown CZT detectors in the prototype PET system, we investigated preliminary research with a developed discrete type data acquisition (DAQ) system for coincident events at 128 anode pixels and two common cathodes of two CZT detectors from Redlen. Each detector has a $19.4{\times}19.4{\times}6mm^3$ volume size with a 2.2 mm anode pixel pitch. Discrete amplifiers consist of a preamplifier with a gain of $8mV{\cdot}fC^{-1}$ and noise of 55 equivalent noise charge (ENC), a $CR-RC^4$ shaping amplifier with a $5{\mu}s$ peak time, and an analog-to-digital converter (ADC) driver. The DAQ system has 65 mega-sample per second flash ADC, a self and external trigger, and a USB 3.0 interface. Results and Discussion: Characteristics such as the current-to-voltage curve, energy resolution, and electron mobility life-time products for CZT detectors are investigated. In addition, preliminary results of gamma ray imaging using 511 keV of a $^{22}Na$ gamma ray source were obtained. Conclusion: In this study, the DAQ system with a CZT radiation sensor was successfully developed and a PET image was acquired by two sets of the developed DAQ system.

• 한국정보시스템학회지:정보시스템연구
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• 제24권4호
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• pp.21-42
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• 2015

Purpose The high-technology market shows characteristics of a highly interdependent network market in both supply-side and demand-side, compared to other markets. Particularly, for convergence products, connectivity with related elements, as well as characteristics of innovation itself, is relatively important to the extent that they combine functions provided by several devices into a single device. Therefore, this study aims to identify whether network externality exists in value and adoption of a convergence product and discover a source of network externality, if any. Design/methodology/approach: Through a preceding research analysis and a literature review, 'social influence' and 'network size' have been drawn as direct network elements. On the other hand, general (comprehensive) concept compatibilities including 'intra-technology compatibility', 'inter-technology compatibility' and 'complementary-technology compatibility' are regarded as indirect network elements. Findings: Major findings are as followed;- First, it is shown that the factors influencing on perceived value of a convergence products are 'social influence' and 'network size' as the direct network elements and 'complementary-compatibility' among indirect network elements. Second, it is also found that 'intra-technology compatibility', 'inter-technology compatibility', 'complementary-compatibility' and 'perceived value' have significant effects on adoption of a convergence product. Particularly, it is known that 'complementary-compatibility' is an important source of network externality as it plays a decisive role in value judgment and has significant effects on perceived value. It is worthwhile to notice that this study comprehensively explains effects of network on high-tech products by structuring comparability as a multi-dimensional concept, as well as direct network elements.

• 비파괴검사학회지
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• 제5권1호
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• pp.34-47
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• 1985

The developing country, KOREA where does not possess the natural resources for traditional energy such as oil and gas, so. The nuclear energy is the most single reliable source available for closing the energy gap. For these reason, It is inavoidable to construct the nuclear power plant and to develop technology related nuclear energy. The rate of operation in large nuclear power facilities depends upon the performance of work system through design and construction, and also the applied technology. Especially, it is the most important element that safety and reliability in operation of nuclear power plant. In view of this aspects, Nuclear power plant is performed severe examinations during preservice and inservice inspection. This study provide an automation of analysis for volumetric examination which is required to nuclear power plant components. It is composed as follows: I. Introduction II. Inservice Inspection of Nuclear Power Plant ${\ast}$ General Requirement. ${\ast}$ Principle and Methods of Ultrasonic Test. ${\ast}$ Study of Flaw Evaluation and Design of Classifying Formula for Flaws. III. Design of Automation for Flaw Evaluation. IV. An Example V. Conclusion In this theory, It is classifying the flaws, the formula of classifying flaws and the design of automation that is the main important point. As motioned the above, Owing to such as automatic design, more time could be allocated to practical test than that of evaluation of defects, Protecting against subjective bias tester by himself and miscalculation by dint of various process of computation. For the more, adopting this method would be used to more retaining for many test data and comparative evaluating during successive inspection intervals. Inspite of limitation for testing method and required application to test components, it provide useful application to flow evaluation for volumetric examination. Owing to the characteristics of nuclear power plant that is highly skill intensive industry and has huze system, the more notice should be concentrated as follows. Establishing rational operation plan, developing various technology, and making the newly designed system for undeveloped sector.

• 한국콘텐츠학회논문지
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• 제15권5호
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• pp.592-606
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• 2015

전 연령층에 걸친 우울증 및 정신질환과 꾸준한 자살률 증가는 정부경쟁력을 크게 떨어뜨리는 심각한 사회문제이다. 정부는 정신건강을 증진시키고 자살을 예방하기 위해 다양한 정책을 실시하고 있으나 시행과정 및 연계 관리 체계 등에서 여러 문제점들이 제기된다. 본 연구는 정신건강분야에 있어 ICT 융합방안의 실태와 방향성을 파악하기 위해 국내외 사례를 살펴보았다. 미국과 영국에서는 ICT를 융합한 원격 정신치료서비스를 지역노인, 소아청소년, 취약계층 등에 제공하고 있다. 국내는 노인자살을 방지하기 위해 독거노인을 대상으로 응급알림 장치를 설치하거나 우울증과 치매 완화를 위한 기술이 개발 중에 있다. 고령화시대에 사회경제적 비용을 줄이고 보편적 복지실현을 위해 ICT 융합 정신건강관리 서비스가 필요하다. 이에 원격정신진료와 관련하여 첨예하게 갈등을 보이는 의료법과 의료기기에 대한 사회적 합의, 생애전주기에 걸쳐 이용자의 정신적 특성을 고려한 효과성 연구, 인구 밀집도와 의료접근성이 낮은 지역 중심의 특화된 정책 등이 제고되어져야한다.

• 한국광학회지
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• 제24권6호
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• pp.311-317
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• 2013

작년 6월 20일, 기존의 일반 카메라에 비해 화질이 1,000배 이상인 초고분해능의 기가픽셀카메라가 미국 듀크대의 과학자들에 의해 네이처에 보고되었고 이를 월스트리트 저널이 보도했다. 보도에 따르면, 이 카메라는 미군부의 필요에 의해 공중 및 지상배치감시를 목적으로 개발되었다는 것이다. 이 기술은 향후 국방과 산업분야의 전반에 걸쳐서 기술.경제적인 파급효과가 매우 클 것으로 예상되기 때문에 국내에서도 시급히 개발에 착수할 필요가 있다고 판단된다. 이에 본 연구에서는 슈퍼 분해능을 갖는 상분할 방식의 기가픽셀 카메라를 구현하기 위한 전초작업으로써 카메라 렌즈시스템의 광학적인 구조를 고찰하였고 더불어 구조와 관련된 렌즈사양 값들의 범위를 계산해 내었다.

• 산업경영시스템학회지
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• 제38권4호
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• pp.72-79
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• 2015

A number of plating companies have been exposed to the risk of fire due to unexpected temperature increasing of water in a plating bath. Since the companies are not able to forecast the unexpected temperature increasing of water and most of raw materials in the plating process have low ignition temperature, it is easy to be exposed to the risk of fire. Thus, the companies have to notice the changes immediately to prevent the risk of fire from plating process. Due to this reason, an agile and systematic temperature monitoring system is required for the plating companies. Unfortunately, in case of small size companies, it is hard to purchase a systematic solution and be offered consulting from one of the risk management consulting companies due to an expensive cost. In addition, most of the companies have insufficient research and development (R&D) experts to autonomously develop the risk management solution. In this article, we developed a real time remote temperature monitoring system which is easy to operate with a lower cost. The system is constructed by using Raspberry Pi single board computer and Android application to release an economic issue for the small sized plating manufacturing companies. The derived system is able to monitor the temperature continuously with tracking the temperature in the batch in a short time and transmit a push-alarm to a target-device located in a remoted area when the temperature exceeds a certain hazardous-temperature level. Therefore, the target small plating company achieves a risk management system with a small cost.