• 천문학논총
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• 제32권1호
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• pp.359-361
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• 2017

We report our research on aluminum mirror optics for future infrared astronomical satellites. For space infrared missions, cooling the whole instrument is crucial to suppress the infrared background and detector noise. In this aspect, aluminum is appropriate for cryogenic optics, because the same material can be used for the whole structure of the instrument including optical components thanks to its excellent machinability, which helps to mitigate optical misalignment at low temperatures. We have fabricated aluminum mirrors with ultra-precision machining and measured the wave front errors (WFEs) of the mirrors with a Fizeau interferometer. Based on the power spectral densities of the WFEs, we confirmed that the surface accuracy of all the mirrors satisfied the requirements for the SPICA Coronagraph Instrument. We then integrated the mirrors into an optical system, and examined the image quality of the system with an optical laser. As a result, the total WFE is estimated to be 33 nm (rms) from the Strehl ratio. This is consistent with the WFEs estimated from the measurement of the individual mirrors.

• 대한방사성의약품학회지
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• 제5권2호
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• pp.71-78
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• 2019

Nuclear imaging is one of the most powerful measures for non-invasive diagnosis of myocardial vascular disease. Radionuclide such as ¹³N, ¹⁵O, ²⁰¹Tl and ⁸²Rb is used for the measurement of cardiac blood flow. ¹³N, ¹⁵O and ²⁰¹Tl are produced in cyclotrons while ⁸²Rb is obtained from generator. Rubidium (Rb), an alkali ion, behaves biologically like potassium, and accumulates in myocardial tissue. Rb has rapid blood clearance profile which allows the use of ⁸²Rb with a short physical half-life of 75 s for non-invasive evaluation of regional myocardial perfusion. There are several advantages of ⁸²Rb over other radioisotopes. An ultra-short half-life significantly reduces the exposure of patients to radiation and allows to repeat injections for studying the effects of medical intervention. As a positron emitter, ⁸²Rb allows positron emission tomography (PET) imaging which have shown superior diagnostic performances. ⁸²Rb can be produced from generator by decay of its parent ⁸²Sr. However, the preparation of ⁸²Sr is difficult, because appropriate purity is required to meet the specification of the product. Recently reported procedure from ARRONAX research institute showed that a Chelex-100 resin is sufficient for this purpose and additional column is not necessary. Whereas Brookhaven National Laboratory (BNL) procedure contains three ion exchange resin separation, including Chelex-100 resin. Currently, since ⁸²Sr production site is non-existent in Korea, Korea Atomic Energy Research Institute (KAERI) has plan to produce ⁸²Sr within specifications. We compared ⁸²Sr purification procedures reported from ARRONAX and BNL to investigate the most suitable procedure for our conditions.

• The Korean Journal of Pain
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• 제31권1호
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• pp.16-26
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• 2018

Background: The aim of this study was to investigate the association between neuroticism, pain catastrophizing, and experimentally induced pain threshold and pain tolerance in a healthy adult sample from two regions of the country of Croatia: the island of Korcula and city of Split. Methods: A total of 1,322 participants were enrolled from the Island of Korcula (n = 824) and the city of Split (n = 498). Participants completed a self-reported personality measure Eysenck Personality Questionnaire (EPQ) and pain catastrophizing questionnaire Pain Catastrophizing Scale (PCS), followed by a mechanical pain pressure threshold and tolerance test. We have explored the mediating role of catastrophizing in the relationship between neuroticism and pain intensity. Results: The results showed that pain catastrophizing partially mediated the relationship between neuroticism and pain intensity, suggesting the importance of pain catastrophizing in increasing vulnerability to pain. The results also indicated gender-related differences, marked by the higher pain threshold and tolerance in men. Conclusions: This study adds to the understanding of the complex interplay between personality and pain, by providing a better understanding of such mechanisms in healthy adults.

• 한국수산과학회지
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• 제22권3호
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• pp.147-153
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• 1989

부산항 부근에서 피스톤식 시추기로 채취된 2개의 세려질 현생퇴적물코어에 대한 음파전달속도와 다른 물리적, 퇴적학적 특성이 측정되었다. 본 연구를 위해 특별히 제작된 실험 보조장치는 성공적으로 작동하였으며, 전통적인 속도측정방법인 수은기둥을 이용한 방법과 디지탈 오씰로스코우프를 이용한 시간차 방법 모두의 측정값이 측정오차 한계인 $1\~2\%$ 이내인 것으로 확인됨으로써 어느 방법이라도 미고결 해저퇴적물의 속도측정에 이용될 수 있음이 증명되었다. 코어에서 직접 측정된 음파전달속도는 약1.540-1.635km/s로서 바로 인접지역에서 탄성파를 이용하여 간접적인 방법으로 계산된 수치인 1.480-1.540km/s 보다 약 $4\~6\%$ 정도 더 빠른 것으로 나타났다. 이러한 차이는 직접측정의 측정오차 한계인 $2\%$를 훨씬 능가하는 것으로 2가지 상이한 측정방법의 근본적인 차이점에 기인한다고 볼 수 있다. 이러한 결과는 기존 탄성파 자료뿐만 아니라 장래에 수행할 각종 해상 탄성파 탐사시 층후계산에 필수적으로 고려해야 할 사항으로서 중요성을 내포한다.

• Journal of Forest and Environmental Science
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• 제25권3호
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• pp.167-175
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• 2009

An exploratory study was conducted in Juri Forest Range-2, a proposed biodiversity conservation area of Bangladesh to explore the present growing stock of tree, regeneration condition and status of non-timber forest products (NTFPs). This conservation area contains both natural and artificial plantation was selected by using multistage random sampling method. For determination of plot size and sampling methods, the quadrate size ($10m{\times}10m$) for tree stock measurement, ($2m{\times}2m$) for regeneration survey, ($20m{\times}20m$) for NTFPs survey was determined. Regarding tree stock survey, 14 species under eight families were found where Tectona grandis shows average number of stem/ha was 624 and basal area/ha was (10.36 $m^2/ha$) followed by Acacia auriculiformis (0.2 $m^2/ha$ and 637 stem/ha), Gmelina arborea (0.2 $m^2/ha$ and 600 stem/ha). In regeneration survey, 14 species were found belonging to 9 families where Alstonia scholaris shows highest (3,750) seedling per hectare. Regarding NTFPs, bamboo and cane are the most common resources. In last ten years, the total timber output was 1,28,596.14 cubic feet and total amount of revenue was 4,64,434 US$. The vacant area is 1,335.5 acre which contains 14% of total area. If this vacant area is planted with suitable species and take proper steps for appropriate management of this species it will be a good biologically diversified area.

• Journal of Biosystems Engineering
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• 제43권4호
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• pp.426-439
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• 2018

Purpose: To continuously monitor soil and climatic properties, a data acquisition system (DAQ) was developed and tested in plum farms (Gyewol-ri and Haechang-ri, Suncheon, Korea). Methods: The DAQ consisted of a Raspberry-Pi processor, a modem, and an ADC board with multiple sensors (soil moisture content (SEN0193), soil temperature (DS18B20), climatic temperature and humidity (DHT22), and rainfall gauge (TR-525M)). In the laboratory, various tests were conducted to calibrate SEN0193 at different soil moistures, soil temperatures, depths, and bulk densities. For performance comparison of the SEN0193 sensor, two commercial moisture sensors (SMS-BTA and WT-1000B) were tested in the field. The collected field data in Raspberry-Pi were transmitted and stored on a web server database through a commercial communications wireless network. Results: In laboratory tests, it was found that the SEN0193 sensor voltage reading increased significantly with an increase in soil bulk density. A linear calibration equation was developed between voltage and soil moisture content depending on the farm soil bulk density. In field tests, the SEN0193 sensor showed linearity (R = 0.76 and 0.73) between output voltage and moisture content; however, the other two sensors showed no linearity, indicating that site-specific calibration is important for accurate sensing. In the long-term monitoring results, it was observed that the measured climate temperature was almost the same as website information. Soil temperature information was higher than the values measured by DS18B20 during spring and summer. However, the local rainfall measured using TR 525M was significantly different from the values on the website. Conclusion: Based on the test results obtained using the developed monitoring system, it is thought that the measurement of various parameters using one device would be helpful in monitoring plum growth. Field data from the local farm monitoring system can be coupled with website information from the weather station and used more efficiently.

• 핵의학기술
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• 제22권2호
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• pp.101-104
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• 2018

Purpose Alpha fetoprotein(AFP) is a fetal serum protein that increases in germ cell tumors derived from liver cancer or egg yolk. AFP test has been used for screening of liver cancer, determination of tumor stage, determination of therapeutic effect, and fetal congenital malformations. The purpose of this study was to compare the results of the four kits, identify the advantages and disadvantages of each kit, and select the appropriate kits for our laboratory. Materials and Methods Blood samples were obtained from 89 patients attending the Seoul national university hospital. Experiments were carried out in accordance with manufacturer's instructions of four companies(A, B, C, D). The precision, recovery, linearity, and sensitivity test were performed for each kit. Results In case of the precision within the measurement, the CV value of the C kit was less than 5% at the low, middle, and high concentrations. The A, B and D kit's the CV value was less than 5% at the concentrations except the low concentration. The recovery rates of the A, B, C, and D kits were $100{\pm}15%$, $100{\pm}30%$, $100{\pm}16%$ and $100{\pm}14%$, respectively. All kits showed good linearity. Sensitivity was measured as 0.5 IU/mL for A, 0.4 IU/mL for B, 0.98 IU/mL for C, and 0.3 IU/mL for D. Conclusion The CV values of the four kits were within 10%, and the correlation coefficients were close to 1 for $R^2=0.978$, $R^2=0.992$ and $R^2=0.8957$. As a result, they are clinically available. Therefore, each laboratory should select the appropriate kit for their experiment's environment.

• 대한치과기공학회지
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• 제45권4호
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• pp.87-94
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• 2023

Purpose: This study aimed to observed changes in the shape of dental barrels based on application time. Machinability measures the angle of alloy specimens. Polishing performance measures the surface roughness of alloy specimens. Methods: The dental barrel polishing equipment used in this study was a Snow Barrel (DK Mungyo). Three types of cobalt-chromium alloys for partial dentures were used as specimens (BC CAST R [BP]; Bukwang, Vera PDI [VP]; Aalbadent, and GM 800+ [GP]; Dentaurum). Specimens were prepared in the form of plates (10 mmx10 mmx2 mm). Dental barrel polishing was performed at 450 rpm for 60 minutes with intervals of 5 minutes. The processing angle was measured using a microscope (SZ61; Olympus). Results: For the angle measurement, the VPC specimen was measured at 78.64°, 36.00° for the VP60 specimen, 79.57° for the BP control (BPC) specimen, 28.07° for the BP60 specimen, 75.01° for the GPC specimen, and 39.92° for the GP60 specimen. For the surface roughness measurements, the average surface roughness of the VPC and VP15 specimens were 1.09 ㎛ and 0.26 ㎛, respectively. The average surface roughness of the BPC and BP20 specimens were 1.77 ㎛ and 0.29 ㎛, respectively. The average surface roughness of the GPC and GP15 specimens were 1.08 ㎛ and 0.27 ㎛. Conclusion: The results were excellent after about 20 minutes of dental barrel polishing conditions presented in this study.

• 대한의생명과학회지
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• 제3권2호
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• pp.115-123
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• 1997

인간 $\alpha$-fetoprotein (AFP)은 간암, 위암, 생식기 종양 및 신경관 이상인 환자를 검사하고 진단하는데 유용한 지표로 알려져 있다. 본 연구에서는 사람의 AFP를 분리정제 하여 폴리클로날 항체를 생산하고 인간 혈장과 양수내의 AFP를 측정하기 위한 경쟁적 효소면역 분석법을 개발하고자 하였다. 친화크로마토그래피법과 SDS-polyacrylamide 전기영동법을 이 용하여 양수로부터 AFP를 분리하였다. 정제된 AFP를 토끼에 주사하여 폴리클로날 항체를 생산하였으며, 이중면역확산법과 Western blot 분석법을 사용하여 본 연구실에서 제조된 항체의 항원 특이성이 대단히 높음을 확인하였다. AFP와 항혈청을 이용하여 표준곡선을 얻었으며, 민감도는 5ng/ml이었고, 작용범위는 5~l,000ng/ml이었다. 분석내 CV는 4.5%이었고, 분석간 CV는 8.5%이었다. 따라서 이러한 결과로 보아 본 연구에서 개발된 경쟁적 효소면역분석법이 AFP를 측정하기에 적절하며, 간암 등의 기초연구에도 많은 기여를 할 것으로 생각된다.

• 대기
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• 제25권4호
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• pp.601-610
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• 2015

This study measured the emissivity spectra of 5 major rock-forming minerals using a Fourier Transform Infrared (FT-IR) spectrometer in the spectral region of $650{\sim}1400cm^{-1}$. The mineral samples are quartz, albite, bytownite, anorthite, and sandstone. We compared emissivity spectra measured in this study with spectra provided by Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Arizona State University (ASU). The spectral features of emissivity such as Reststrahlen Band (RB) and Christiansen Feature (CF) locations were compared. Results showed that both CF and RB locations of emissivity spectra measured in this study were similar to those from ASTER and ASU. In the case of quartz, the RB was occurred in the region of $700{\sim}850cm^{-1}$ and $1050{\sim}1250cm^{-1}$. The spectral position of emissivity peak was in good agreement with the location of ASTER and ASU. For plagioclase (albite, bytownite, and anorthite), the spectral location of CF was shifted toward larger wavenumber and the emissivity value was increased in the region of $870{\sim}1200cm^{-1}$ with Ca percentage. The CF of anorthite and bytownite was occurred at $1245.79cm^{-1}$, and that of albite was occurred at $1283.79cm^{-1}$. We also confirmed that emissivity feature of sandstone includes both emissivity features of quartz and calcite. However, there were some differences in the magnitude of emissivity and locations of RB and CF. These were due to the differences in measurement methods, and differences in particle size and temperature of samples.