• Tunnel and Underground Space
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• v.14 no.1
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• pp.35-42
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• 2004

Impact-echo is a method for non-destructive testing of concrete structure. This method is based on the use of impact-generated stress wave which is propagated and reflected from internal flaws within concrete structure and external surface. In this study, we performed non-destructive testing using impact-echo methods for safety diagnosis of civil engineering and building structures. There are testing cases for the three models having one-dimensional form ; The first case is the measurement of thickness change of the model, the second is the detection of cavity in the model, and the third is the predictions of the lining thickness and the position of the cavity under tunnel lining condition.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.9
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• pp.605-613
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• 2010

Double skin facade(DSF) ventilated by fans consists of a normal external and an internal envelope. In this glass layer, the installed fan replaces an air inlet for the control of air flow through the cavity. The purpose of this paper is to investigate physical theory and to analyze the applicability of fans installed in a DSF. The experiment was conducted in 2 rooms. One room has a DSF with installed fans and the other one has a typical window. The room ventilated through a DSF which fans are installed was always kept warmer than the other room, ventilated directly from the outdoors. The average increase of the supplied air temperature through the DSF ventilated by fans was $6.54^{\circ}C$ at 78CMH, $6.2^{\circ}C$ at 95CMH, and $3.7^{\circ}C$ at 120CMH. As a result, the DSF with installed fans was appropriate for installation in rooms. It supplies outdoor fresh air heated through a cavity and ventilates a constant air volume.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.63-70
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• 2011

To consider the iliac fossa as the vascular anastomosis site of kidney transplantation for the short-term study of acute rejection in pigs. Twelve domestic pigs weighing 39~48 kg underwent heterotopic renal allgraft transplantation. The experimental animals were divided into 2 groups in terms of renal vascular anastomosis site; the external iliac artery and vein were used in iliac fossa model (n = 6), the abdominal aorta and the caudal vena cava inferior to the kidney were used in abdominal cavity model (n = 6). Renal function was evaluated by daily measurement of plasma creatinine and BUN concentrations. The experiments' health including postoperative complications was also assessed daily for 8 days after transplantation. After euthanazation gross and histopathologic analysis was performed. All six pigs in iliac fossa model developed neuropraxia and lameness of the ipsilateral pelvic limb. However, no necrosis was observed in any pigs. In the abdominal cavity model, durations of both the surgical operation and the vascular anastomosis were significantly longer than those in the iliac fossa model. Furthermore, ischemia injury of the transplanted kidney was increased in abdominal cavity model, which induced accelerated-acute immune response from day 4 after transplantation. Despite of pelvic limb complication, the iliac fossa model showed more advantages including not only less ischemia time related to easy vascular anastomosis, but also less immune response during the acute rejection period. The results indicate that the iliac fossa model may be appropriate to the study of acute rejection in porcine kidney transplantation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.169-173
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• 2014

In order to satisfy user's requirements of needs for various services and to efficiently use of frequency, a communication system using one platform can support many communication services. Tunable filters must be used in the front end of broadband communication systems which provide and support various communication methods. In this paper we design and implement a filter bank to verify the feasibility of cavity tunable filter with the operation frequency of 800 MHz ~ 1600 MHz. The filter bank is composed of five bandpass filters and each bandpass filter has the same operation frequency band of the tunable filter. The implemented filter bank has the maximum insertion loss of 0.326 dB, the bandwidth of 37 MHz ~ 84 MHz, and the attenuation of minimum 19.974dB and mximum 37.812dB at the band edge ${\pm}60MHz$ over the operating frequency band.

• Korean Journal of Optics and Photonics
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• v.5 no.1
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• pp.144-151
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• 1994

We designed and fabricated a $2{\times}4$ symmetric self electro-optic effect device array using GaAs/ AIo.04 G$\DeltaR$), and optical bistability loop width ($\Delta$). The average values of the elements of the $2{\times}4$ S-SEED array were CR~13.1, R~24%, and $\Delta$~91%. It was found that the AFP cavity structure enhances the self-biased optical bistability in ESQW-SEED under no external bias. That is due to the decreased intrisic region thickness in AFP-SEED structures, and which increases the built-in electric fields. The zero-biased S-SEED showed CR of ~4.7, R~9%, and $\Delta$~22%.X>~22%.

• The Journal of the Acoustical Society of Korea
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• v.31 no.5
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• pp.288-297
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• 2012

This study proposes a design model of the variable type resonator which corrects the temperature variance according to the season, in order to maximize the resonance effect in the Sacred bell of the Great King Seongdeok. In the bell, the 1st natural frequency (64 Hz) and the 2nd natural frequency (168 Hz) are the most important partial tones. Resonance conditions of the two components are determined for the internal acoustic cavity system, which consists of bell body cavity, gap and the resonator. Acoustic frequency response characteristics of the internal cavity are determined by the boundary element analysis using SYSNOISE. As an external factor, temperature variance according to the season largely influences the resonance condition and the length of the resonator should be controlled to maximize the resonance effect. As a measure, this study proposes a design model of the variable type resonator for the Sacred Bell of the Great King Seongdeok, which can control the length at the belfry according to the season.

• Korean Journal of Optics and Photonics
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• v.25 no.1
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• pp.38-43
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• 2014

An external cavity laser supporting two wavelengths is demonstrated by incorporating polymer waveguide Bragg reflectors and a superluminescent light-emitting diode. An oversized rib waveguide structure and Bragg gratings are designed by using the effective-index and transmission-matrix methods. Bragg gratings with different periods are inscribed on a polymer waveguide through double-exposure laser interferometry. In order to tune the cavity loss affected by the reflectivity of Bragg gratings, a Bragg reflectors with varying length is incorporated. Two-wavelength-mode lasing is achieved for the device consisting of 2-mm long, 537-nm period gratings and 2.2-mm long, 540-nm period gratings; the lasing wavelengths are 1554 nm and 1564 nm, with an output power close to 0 dBm, a 20-dB bandwidth of 0.2 nm, and a side-mode suppression ratio of 45 dB.

• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.351-361
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• 2015

External reactor vessel cooling (ERVC) for in-vessel retention (IVR) has been considered one of the most useful strategies to mitigate severe accidents. However, reliability of this common idea is weakened because many studies were focused on critical heat flux whereas there were diverse uncertainties in structural behaviors as well as thermal-hydraulic phenomena. In the present study, several key factors related to molten corium behaviors and thermal characteristics were examined under multi-layered corium formation conditions. Thereafter, systematic finite element analyses and subsequent damage evaluation with varying parameters were performed on a representative reactor pressure vessel (RPV) to figure out the possibility of high temperature induced failures. From the sensitivity analyses, it was proven that the reactor cavity should be flooded up to the top of the metal layer at least for successful accomplishment of the IVR-ERVC strategy. The thermal flux due to corium formation and the relocation time were also identified as crucial parameters. Moreover, three-layered corium formation conditions led to higher maximum von Mises stress values and consequently shorter creep rupture times as well as higher damage factors of the RPV than those obtained from two-layered conditions.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.7 no.1
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• pp.53-84
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• 1994

The study has been carried out to investigate of the Allergic Rhinitis by referring to 87 literatures. The results were as follows; 1. In oriental medical science, Allergic Rhinitis is belong to the category of the 'BiGu'(鼻구) 'GuChe'(구체). The 'Gu'(구) of the BiGu means watery rhinorrhea, the 'Che'(체) of the GuChe means sneezing. 2. The cause of a disease summarize the weak of Lung, Spleen and Kidney, and invasion into the nasal cavity of PoongHan etc a wrong air. Sometimes the pathologial change appear PoongHan changeHwa(風寒化火), HwaYeol is hidden in the inside(火熱內伏). The contributing factors are found a season(spring, winter), an abnormal weather(運氣 : 少陰 少陽 陽明 司天, 歲金不及), an emotional stress, an external wound of the harmful air, a food allergens and fatigue, a contact of substances, a sunlight etc. 3. Predominant symptoms are watery rhinorrhea, sneezing and nasal obstruction. Sometimes accompanic symptoms are nasal bleeding, mucopurulent rhinorrhea, olfactory disturbance, nasal polyp, rhinolalia clausa, respiratory disfunction etc. 4. The treatment-methodes is as follows, OnBoPaeJang GeoPoongSanHan(溫補肺臟 祛風散寒), GeonBilkGi(健脾益氣), BoSinNabGi (補腎納氣). The treatmentherbs is as follows, OnBoJiLuDan GaGam(溫補止流丹 加減), OkByeongPoongSan plus ChangIJaSan GaGam(玉屛風散合 蒼耳子散 加減), BoJungIkGiTang GaGam plus SoCheongLyongTang(補中益氣湯加減 配合 小靑龍湯), SinGiHwan GaGam(腎氣丸加減), GaeJiTang(桂枝湯) etc. 5. The external treatment is as follows, JeokBi(滴鼻), ChuiBi(吹鼻), SaekBi(塞鼻), stick and herbs-injection on the acupuncture-point, pressure ear acupuncture-point, herbs-pillow etc. 6. The acupuncture-moxa treatment is as follows, the methodes of cure apply TongJoGyeongGi(通調經氣), SanTongBiGui(宣通鼻竅) etc. Predominent acupuncture-points are YoungHyang(迎香), InDang(印堂), BiTong(鼻通), SangSeong(上星), HabGok(合谷) and so on. As mentioned above, from now on, it's need to the oriental medical scientific study of the Immunity and Allergy and to the external treatment's application for the ascent of the treatment-effect of the allergic disease.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.6
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• pp.455-461
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• 2004

The morphological and histological changes of gonad in ridgetail prawn (Expalaemon carinicauda) were examined with the development of the external genitalia. The samples were collected monthly in Hampyung Bay on the western coast of Korea, from January to December 2003. The ovaries lie on the dorsal side of the female prawns thorax. The ovary cavity is located below the heart and above the hepatopancreas. The anterior part of the ovary is round and fused, and the posterior part has a pair of tubular structures. Testes are bilaterally symmetrical; the anterior part shows fused feature, and the posterior part consists of a pair of tubules. Based on histological examination, ripe eggs and spermatozoa were observed when mature females and males reach a length of about 14.9 and 11.5 mm CL, respectively. The immature female are almost same shape and structure with matured one in the endopod of first pleopod and appendix interna of the second pleopod, except the number of setae, and appear to be structurally complete after females reach a length of about 14.9 mm CL. The appendix masculina reaching beyond the distal end of the appendix interna of the second pleopod after males reach a length of more than 5.5 mm CL and a fully developed appendix masculina and appendix interna of the second pleopod appear up to a length of 11.5 mm CL.