• Korean Journal of Heritage: History & Science
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• v.36
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• pp.181-226
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• 2003

In archeological aspects the 4th-6th centuries of the Silla kingdom has been callded the era of wooden chamber tombs with pebble and earth mounds(jeokseokmokwakbun). Moreover, the era is also regarded the age of the traditional and 'primitive' Korean religion which originated from inside the Korean Peninsula or the kingdom. However, the tombs and their burial accessories reveal that it is Taoism, not shamanism, that prevailed throughout the silla kingdom and its people during the jeokseokmokwakbun period. Above all things, almost all of the tombs excavated up to date yield in great quantities cinnabar and mica, which have been considered the best elixir of life in the Taoist world. Moreover the instruments to make the medicine for the deceased has been founded inside a tomb. The jeokseokmokwakbun tombs are famous for their great amount of buried articles and their grand scale. The tombs also have a large amount of gold, silver and beads, which are all thought to be the other cure-alls in taoism. Then why the silla people made the tombs and buried those elixirs of life for the deceased? The best answer we can imagine is this : for eternal living! In other words, cinnabar and mica are for the everlasting life of the deceased, the tombs were desingned as the 'eternal house' where the dead are living a immortal life. Needless to say, immortal living, even after he or she dies, is the ultimate purpose of taoism.

• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.457-463
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• 2013

PURPOSE. The purpose of this study was to compare the effect of a diode laser and traditional irrigants on the bond strength of self-adhesive cement. MATERIALS AND METHODS. Fifty-five incisors extracted due to periodontal problems were used. All teeth were instrumented using a set of rotary root canal instruments. The post spaces were enlarged for a No.14 (diameter, 1.4 mm) Snowlight (Abrasive technology, OH, USA) glass fiber reinforced composite post with matching drill. The teeth were randomly divided into 5 experimental groups of 11 teeth each. The post spaces were treated with the followings: Group 1: 5 mL 0.9% physiological saline; Group 2: 5 mL 5.25% sodium hypochlorite; Group 3: 5 mL 17% ethylene diamine tetra acetic acid (EDTA), Group 4: 37% orthophosphoric acid and Group 5: Photodynamic diode laser irradiation for 1 minute after application of light-active dye solution. Snowlight posts were luted with self-adhesive resin cement. Each root was sectioned perpendicular to its long axis to create 1 mm thick specimens. The push-out bond strength test method was used to measure bond strength. One tooth from each group was processed for scanning electron microscopic analysis. RESULTS. Bond strength values were as follow: Group 1 = 4.15 MPa; Group 2 = 3.00 MPa; Group 3 = 4.45 MPa; Group 4 = 6.96 MPa; and Group 5 = 8.93 MPa. These values were analysed using one-way ANOVA and Tukey honestly significant difference test (P<.05). Significantly higher bond strength values were obtained with the diode laser and orthophosphoric acid (P<.05). There were no differences found between the other groups (P> .05). CONCLUSION. Orthophosphoric acid and EDTA were more effective methods for removing the smear layer than the diode laser. However, the diode laser and orthophosphoric acid were more effective at the cement dentin interface than the EDTA, Therefore, modifying the smear layer may be more effective when a self-adhesive system is used.

• The Journal of the Acoustical Society of Korea
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• v.16 no.2E
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• pp.3-13
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• 1997

The Jing is a traditional Korean percussion instrument which plays a major role in Korean folk music. The distingishing feature of this instrument is its unique, long lasting low tone timbre. In this paper, we investigated the vibro-acoustic characteristics of the Jing. Our attention was focused mainly on findings out the physical variables that determine its unique sound. By understanding the way in which the Jing is manufactured, we were able to realize that the unique manufacturing and especially the tuning process by expert craftsman is responsible for the peculiar timbre the Jing produces. The experimental methods implemented to analyzer the Jing were planar acoustic holography and direct measurements by accelerometers. The results from the holographic method and the direct measurements were in good agreement. It turned out that unlike most percussion instruments which have inharmonic partials, the Jing has harmonic partials which are responsible for its unique low-tone timbre. From the holographic representations of the modes, it is clear that the antinodes are located in the center of the Jing which is coincident with the typical striking location. In addition, intensity maps were constructed so that the specific acoustic energy flow can be visualized. It was also interesting to see the the circulation of energy intensity which corresponds to the rotating mode of the Jing.

• Korean Journal of Bronchoesophagology
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• v.4 no.2
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• pp.159-164
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• 1998

The developmental and subsequent addition of laser technology to existing surgical techniques offered new and exciting Possibilities for improving traditional endoscopic operations and expanding the scope of the specialty of otolaryngology-head and neck surgery. Lasers were found to be Precise, but potentially dangerous, surgical instruments whose use was associated with certain distinct and unprecedented advantages, but also with many unique and potentially serious, and sometimes catastrophic complications. The Purpose of this study was to evaluate the of elation technique of $CO_2$laser, kinds of anesthesia, equipments of operating room, and education of medical staff. Four hundreds 4 cases of $CO_2$laser laryngeal microsurgery were reviewed for the safety of $CO_2$laser in laryngeal microsurgery. Vocal polyp (46,3%) was the most common pathology in our cases. The others were vocal nodule, Reinke`s edema, epiglottic cyst, laryngeal granuloma, laryngeal papilloma, intracordal cysts, laryngeal tuberculosis, laryngeal web, laryngotracheal stenosis, and laryngeal cancer. Following complete equipment controls, treatment area controls, maintenance, service and procedural controls, personel protective equipment, and warning signs, no complications were found in our cases. In conclusion, laryngeal microsurgery with $CO_2$laser could be done safely without complication if complete preoperative preparation and education of medical staff preceded.

• Journal of the Korean Wood Science and Technology
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• v.26 no.4
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• pp.26-33
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• 1998

Acoustical properties of chestnut and paulownia woods have been determined in four film thicknesses of oriental lacquering and cashew varnishing on double surfaces of soundboard to elucidate effects of finishing. Accelerometer was attached to the specimen at one third position from one end, and specimen was hit by the impact hammer at one third position from opposite end. Data were processed by vibration analyzer. The ratio of axial-to-transverse sound velocity of untreated specimens of chestnut and paulownia were 3.25 and 5.34, respectively. Natural frequency, specific Young's modulus, acoustical coefficient, sound velocity, damping of sound radiation(DSR) and acoustical converting efficiency(ACE) decreased by oriental lacquering and cashew varnishing for both species. Damping of internal friction of chestnut decreased by oriental lacquering and cashew varnishing, but that of paulownia increased. Natural frequency. specific Young's modulus, acoustical coefficient, sound velocity, and DSR decreased with increased film thickness of both finishing materials. However, damping of internal friction and ACE showed irregular tendency with increased film thickness. Acoustical properties of cashew varnished chestnut specimen were better than those of oriental lacquered specimen. Acoustical properties of oriental lacquered paulownia specimen were better than those of cashew varnished specimen.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.551-554
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• 2004

현재 국악기의 음향특성에 대한 상세 정보가 매우 부족하며, 이러한 점보의 부재는 국악당의 설계에 있어서 최적의 음향을 전달하는 공간을 형성하지 못하게 하는 한 원인이 되고 있다. 따라서, 대표적인 각종 국악기의 음향특성을 측정하고 분류한 후 데이터베이스를 구축하면, (1) 향후의 국악 및 국악기 개발에 대한 기초연구로서 활용들 수 있으며, (2) 국악전용 연주장의 설계에 있어서 입력 데이터로 요긴하게 활용될 수 있으리라 판단된다. 본 연구는 국악기의 음향방사특성을 조사하기 위한 제 2 단계의 연구로서, 기존의 연구 [1] 에 새로운 국악기 8 종을 추가하였다. 선정된 국악기는 현악기중에서 거문고와 해금, 관악기 중에서 피리와 태평소, 타악기 중 북과 꽹가리, 징 및 남성창으로, 원거리 (far-field) 음향 방사 특성을 조사하였다.

• Journal of Ocean Engineering and Technology
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• v.24 no.6
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• pp.103-108
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• 2010

WIG crafts are high speed vessels with the features of a dynamic supported craft. These crafts, which are predominantly lightweight and operate at substantially greater speeds than conventional craft, could not be accommodated under traditional maritime safety instruments. WIG crafts inherently possess more hazard factors than conventional ships because of their relatively high speed, lightweight, and navigational characteristics, and an accident is likely to cause damage to the ship and a high loss of life. Because WIG crafts are composed of many systems and subsystems, the safety assessment of a WIG must use a commercial software system in the design stage. This paper reviews a safety assessment process and methodology proposed by the IMO interim guideline, which were developed in view of the configuration of WIG crafts. This safety assessment system was developed to fit the WIG's safety assessment process using a reliability analysis system widely used in commercial systems. The FHA was performed on the functional hazards of systems in the conceptual design stage.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.222-227
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• 2003

Recent advances in room-temperature, visible and near-IR diode laser sources for telecommunication, optical data storage applications are enabling combustion diagnostics system based on diode laser absorption spectroscopy. In contrast to some traditional sampling-based gas-sensing instruments, tunable diode laser absorption spectroscopy system is advantageous because of their non-invasive nature, high sensitivity, fast response time and real-time measurement capability. So, combined with fiber-optics and high sensitive detection strategies, compact and portable sensor system arc now appearing for a variety of applications. The objective of this research is to take advantage of distributed feed-back diode laser and measure the $CO_{2}$ concentration (by using direct absorption and wavelength modulation spectroscopy methods). In addition to survey spectra of $CO_{2}$ bands and spectroscopic parameters between 1565 and 1579 run were computed at temperatures between 296 and 1200 K (by using HITRAN 2000 database). It experimentally found out that the features of direct absorption and wavelength modulation spectroscopy methods.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1542-1549
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• 2009

The function of subgrade in the railway is to support track load on the subgrade as well as train load. Unlike the traditional railway, the uppermost subgrade layer in the Gyeongbu high speed railway was constructed as the reinforced road bed. The reinforced road bed comprises sub-ballast in the upper part and grade ballast in the lower part. The filling material such as soil and rocks in the subgrade can be settled by consolidation of original ground, compression due to self weight, plastic displacement due to train operation, and unequal settlement due to embankment material or improper compaction, therefore many efforts have been given for sufficient compaction and use of proper filling materials in the construction stage. The purpose of this study is to investigate the deformation state of subgrade in the Gyeongbu high speed railway. The investigation on the subgrade settlement was performed by choosing representative sections suspected to be settled based on the previous GPR test results and track maintenance history, measuring the settlement for some time period after installing settlement measuring instruments on and under the reinforced road bed. and analyzing the long-term subgrade settlement data from monitoring system which was installed at the construction stage of the high speed railway.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1209-1223
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• 2022

Blood pressure is one of the key physiological parameters for determining human health, and can prove whether human cardiovascular function is healthy or not. In general, what we call blood pressure refers to arterial blood pressure. Blood pressure fluctuates greatly and, due to the influence of various factors, even varies with each heartbeat. Therefore, achievement of continuous blood pressure measurement is particularly important for more accurate diagnosis. It is difficult to achieve long-term continuous blood pressure monitoring with traditional measurement methods due to the continuous wear of measuring instruments. On the other hand, radar technology is not easily affected by environmental factors and is capable of strong penetration. In this study, by using machine learning, tried to develop a linear blood pressure prediction model using data from a public database. The radar sensor evaluates the measured object, obtains the pulse waveform data, calculates the pulse transmission time, and obtains the blood pressure data through linear model regression analysis. Confirm its availability to facilitate follow-up research, such as integrating other sensors, collecting temperature, heartbeat, respiratory pulse and other data, and seeking medical treatment in time in case of abnormalities.