• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1206-1218
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• 2016

This article proposes a highly reliable power and communication system that guarantees the protection of essential instruments in a nuclear power plant under a severe accident. Both power and communication lines are established with not only conventional wired channels, but also the proposed wireless channels for emergency reserve. An inductive power transfer system is selected due to its robust power transfer characteristics under high temperature, high pressure, and highly humid environments with a large amount of scattered debris after a severe accident. A thermal insulation box and a glass-fiber reinforced plastic box are proposed to protect the essential instruments, including vulnerable electronic circuits, from extremely high temperatures of up to $627^{\circ}C$ and pressure of up to 5 bar. The proposed wireless power and communication system is experimentally verified by an inductive power transfer system prototype having a dipole coil structure and prototype Zigbee modules over a 7-m distance, where both the thermal insulation box and the glass-fiber reinforced plastic box are fabricated and tested using a high-temperature chamber. Moreover, an experiment on the effects of a high radiation environment on various electronic devices is conducted based on the radiation test having a maximum accumulated dose of 27 Mrad.

• Journal of Music and Human Behavior
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• v.18 no.2
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• pp.87-107
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• 2021

The purpose of this research was to explore the phenomenon of object relations with musical instruments as experienced by professional Samulnori musicians. The researcher conducted in-depth individual interviews with five Samulnori players who also completed questionnaires with open-ended questions. The data were analyzed using Giorgi(2004)'s phenomenological methodology. The results offered 121 semantic units, seven subcategories, and three main categories. The three main categories were transitional object, object of expression and recognition of internal desires, and object for recognition of others and communication. These results suggest that the ensemble format of Samulnori promotes the development of the musician's object relationship and can externalize the player's internalized representational system and interaction method. This study is significant in that it reveals the endopsychic functional relationship between a musician and their instrument and provides the basis for the use of Samulnori instruments in music therapy.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.281-314
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• 2006

Several explanations exist about the usage of disk-shaped bronze implements in the ancient society. Some argue that they were used as mirrors, others suggest percussion instruments, and still others bronze ornaments. Differences between disk-shaped bronze implements and mirrors with multiple knobs are that the former have no visible design, only one handle, and a sharp curvature unlike the latter with smooth curvature. The question is whether disk-shaped bronze implements excavated from Korean peninsula have any light reflecting function. To answer this question, I carefully studied the concave surfaces of disk-shaped bronze implements excavated from Goejeong-dong, Tongso-ri and Hapsong-ri sites. The main findings are as follows: (1) The concave sides of the disk-shaped bronze implements excavated from Goejeong-dong and Tongso-ri sites were highly polished, and they were as reflective as bronze mirrors. (2) The concave side of the disk-shaped bronze implement from Hapsong-ri site was unpolished, and it was different from bronze mirrors. (3) As for the convex sides of the disk-shaped bronze implements, they did not appear to have been polished with care. Considering the above findings, the disk-shaped bronze implements excavated from Goejeong-dong and Tongso-ri sites belong to the stage where they could act as both mirrors and instruments. On the contrary, the disk-shaped bronze implement from Hapsong-ri site can belong to the stage where it lost the function of being a mirror as the result of maintaining only its function as an instrument. Even though disk-shaped implements had two functions, it can be considered that the light reflecting function expanded the role of a mirror with multiple knobs and the sound function helped the engraved round bronze implement to be converted into an eight-armed bronze rattle. Since it has been reported that shamans used bronze mirrors as percussion instruments in their performances in Korean peninsula and Siberia, I propose a reconsideration of the usage of mirrors in the ancient East Asia. Although the essential function of a mirror is to reflect light, other possible usages involving important functions need to be further investigated.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.6
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• pp.21-27
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• 2023

Modern naval ships install an Infra-Red Signature Suppression system (IRSS) in their exhaust pipe to reduce infrared signature emitted to the outside. In addition, naval ships are strategic assets with a very long life cycle, so high reliability of the performance of the equipment on board must be guaranteed. Therefore, equipment such as IRSS is evaluated for performance through model testing at the design stage. A variety of measuring instruments are used in IRSS model testing, and the reliability of these instruments must also be guaranteed. In this paper, a study was conducted to evaluate the reliability of measurement equipment used in IRSS model testing. The test equipment and instruments used were a hot gas wind tunnel, pitot tube, digital differential pressure gauge, thermocouple sensor, and digital recorder. As the fan speed of the hot gas wind tunnel increased, the measurement deviation of the flow decreased, and the temperature output of the thermocouple sensor showed differences in response time and stability depending on the method used.

• Journal of Environmental Policy
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• v.11 no.3
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• pp.123-148
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• 2012

Deforestation and forest degradation in Democratic People's Republic of Korea (DPRK) accelerated from the mid 1980s through the economic crisis in 1990s and is still happening. DPRK has conducted afforestation and reforestation activities against this trend. However there are not many official documents on achievement of forest rehabilitation in DPRK. "Rodong Shinmun," as an official newspaper published by North Korean Workers Party, represents governmental policies and is one of a few accessible information on DPRK which is available in Republic of Korea (ROK). This paper aims to investigate the national forest policies of the DPRK represented in Rodong Shinmun. Total of 499 articles using the word 'Sanlim (forest)' and 'Rimsan (forest product)' in the title of articles were selected for content analysis. The national forest plans and forest policy instruments contained in the selected articles were analyzed. The subjects of represented forest policies were classified into four groups; forestation, forest management, land management and forest protection or conservation. The focus of forest policy was changed from economic utilization of forest resources such as timber production in the 1990s to forest protection in the 2000s. Rodong Shinmun reported more frequently about regulatory instruments and informational instruments than the economic instruments. Official commendation and awards were the main incentives given to the people who contributed to forestry achievements. In particular, forest policies were emphasized by Kim Il Sung and Kim Jong Il and afforestation and forest protection were described as patriotic activities in the Rodong Shinmun. In conclusion, this research revealed that Rodong Shinmun plays a role as a means for introducing, propagating and instigating forest policies in the society of the DPRK. The findings help to understand the forest policies of the DPRK which could be useful when designing development aids for DPRK.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.134-140
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• 2005

The purpose of this study was the discrimination of different tobacco types by the E-Nose/tongue and the analysis of what human sensory attributes are correlated with e-instrument's sensors. Samples were made from five groups of Korean domestic tobacco leaves, aged burley and not aged, aged flue-cured and not aged and blending types of the four. Instrumental tests were conducted to discriminate characteristics among different tobacco samples by the E-Nose and the E-Tongue. Sensory attributes of tobacco tastes were impact, irritation, bitterness, hay-like, tobacco taste, smoke volume, smoke pungent and mouth cleanness. STATISTICA software was used to analyze correlation between the human sensory data and the raw data of e-instruments. Discrimination analysis can be achieved using principal components analysis (PCA) and discriminant factorial analysis(DFA). As a result, impact, bitterness, irritation, smoke volume and smoke pungent of human sensory attributes were correlated with data from the several clustered E-Nose sensors(p < 0.10). And bitterness, irritation, and smoke pungent of human sensory attributes were correlated with data from the E-Tongue sensors(p < 0.10). PCA plot by the E-Nose shows that aged tobacco and not aged were discriminated and DFA plot shows that three groups(aged burley, not aged burley and flue-cured) were discriminated. PCA plot by the E- Tongue shows that flue-cured tobacco was separated from burley. Our results indicated that the e-instruments are sensitive enough to distinguish among tobacco types and their several sensors are reacted to the human sensory attributes.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.607-621
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• 1999

This study examined the human fibroblasts cell attachment to commercially pure titanium surface which had been instrumented by 3 types of periodontal instruments. Commercially pure titanium plates were uniformly scaled using plastic, stainless steel, titanium curette. these all experimental groups 65 undirectional strokes with the designated curettes. Alteration of the surfaces due to instrumentation was evaluated by Form Talysurf(R) and reported as Ra value(mean surface roughness). Then other experimental groups were immersed in a cell suspension of human gingival fibroblasts($1{\times}10^5$ cell/ml). After 3 days of culture, cell attachment and morphology was observed by SEM, and attached cell were counted by Hemocytometer. A significant difference in mean Ra value was observed for surface instrumented by metal curette compared to either control surface or surface instrumented by the plastic curette(P<0.01). No stastically significant difference was noted between control surface and those instrumented by the plastic curette. SEM observation showed that cell morphology and attachment to the commercially pure titanium plate was similar appearance on the all experimental groups. Experimental groups instrumented by titanium curette and stainless steel curette were more attached cell number than control group, but experimental group instrumented by plastic curette were similar with control groups(P<0.01). In summary, metal curette produced an significant alteration of the commercially pure titanium surface and more favorable surface topography for cell attachment. Otherwise plastic curette was insignificantly altered the commercially pure titanium surface(P<0.01).

• Journal of Korean Neurosurgical Society
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• v.49 no.4
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• pp.248-251
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• 2011

Objective : In the field of spinal surgery, a few laboratory results or clinical cases about robotic spinal surgery have been reported. In vivo trials and development of related surgical instruments for spinal surgery are required before its clinical application. We investigated the use of the da $Vinci^{(R)}$ Surgical System in spinal surgery at the craniovertebral junction in a human cadaver to demonstrate the efficacy and pitfalls of robotic surgery. Methods : Dissection of pharyngeal wall to the exposure of C1 and odontoid process was performed with full robotic procedure. Although assistance of another surgeon was necessary for drilling and removal of odontoid process due to the lack of appropriate end-effectors, successful robotic procedures for dural sutures and exposing spinal cord proved its safety and dexterity. Results : Robot-assisted odontoidectomy was successfully performed in a human cadaver using the da $Vinci^{(R)}$ Surgical System with few robotic arm collisions and minimal soft tissue damages. Da $Vinci^{(R)}$ Surgical System manifested more dexterous movement than human hands in the deep and narrow oral cavity. Furthermore, sutures with robotic procedure in the oral cavity demonstrated the advantage over conventional procedure. Conclusion : Presenting cadaveric study proved the probability of robot-assisted transoral approach. However, the development of robotic instruments specific to spinal surgery must first precede its clinical application.

• Proceedings of the KSRS Conference
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• v.1
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• pp.86-89
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• 2006

Ocean color remote sensing community currently uses the different solar irradiance spectra covering the visible and near-infrared in the calibration/validation and deriving products of ocean color instruments. These spectra derived from single and / or multiple measurements sets or models have significant discrepancies, primarily due to variation of the solar activity and uncertainties in the measurements from various instruments and their different calibration standards. Thus, it is prudent to examine model-to-model differences and select a standard reference spectrum that can be adopted in the future calibration and validation processes, particularly of the first Geostationary Ocean Color Imager (GOCI) onboard its Communication Ocean and Meterological Satellite (COMS) planned to be launched in 2008. From an exhaustive survey that reveals a variety of solar spectra in the literature, only eight spectra are considered here seeing as reference in many remote sensing applications. Several criteria are designed to define the reference spectrum: i.e., minimum spectral range of 350-1200nm, based completely or mostly on direct measurements, possible update of data and less errors. A careful analysis of these spectra reveals that the Thuillier 2004 spectrum seems to be very identical compared to other spectra, primarily because it represents very high spectral resolution and the current state of the art in solar irradiance spectra of exceptionally low uncertainty ${\sim}0.1%.$ This study also suggests use of the Gueymard 2004 spectrum as an alternative for applications of multispectral/multipurpose satellite sensors covering the terrestrial regions of interest, where it provides spectral converge beyond 2400nm of the Thuillier 2004 spectrum. Since the solar-activity induced spectral variation is about less than 0.1% and a large portion of this variability occurs particularly in the ultraviolet portion of the electromagnetic spectrum that is the region of less interest for the ocean color community, we disregard considering this variability in the analysis of solar irradiance spectra, although determine the solar constant 1366.1 $Wm^{-2}$ to be proposed for an improved approximation of the extraterrestrial solar spectrum in the visible and NIR region.

• Journal of The Korean Association For Science Education
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• v.9 no.2
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• pp.81-87
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• 1989

In 1987 Ministry of Education published the 5th-revised version of curriculm, the main goal of which is to improve science and culture as well as to educate the students who are able to actively adapt to the 21st century's society. Howerver, the revised curriculum neglects the problems associated with the nature of and localized characteristics of science education. Therefore this research had its main objective to survey and analyze the status of science education of secondary schools in Kangwon Province and, based on the results, to develop the teaching/learning materials appropriate for science education in this province. This research is 3d-Year project and this paper is about its first year research results. The first year's main objective is to investigate and analyze the status of middle school science education, focusing on the curricular operation, science teachers, and lavoratory facilities and instruments. This research used the survey methods. The questionaires were sent to all the middle schools the number of which is 163, and 162 schools of which returned the survey questionaires. Based on the analyses of the data following conclusions were drawn. The average class size is 48.8 students. Almost all of the middle schools alocate the science class hours per week of 4,3,4 hours to first, second, third grade, respectively. However, the greater part of science teachers want 5,4,5 hours of science classes a week. Total number of science teachers exeeds the number actually needed, implicating that many science teachers are teaching non-major subjects. The lavoratory facilities and instruments are not sufficiently provided for lavoratory-based science education. Along with these conclusinons suggestions for better science educations are recommanded. Among the suggestions two are highly emphasized.They are: to increase science class hours; to use field lavoratory substituting for school lavoratory.