• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.67.2-67.2
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• 2010

We present results of searching for the Very Low Luminosity Objects (VeLLOs; internal luminosity : $L_{int}$ < $0.1(d/140pc)^2\;L\odot$) in the Gould's Belt clouds using observations from 3.6 to 70 micron by the Spitzer Space Telescope. The clouds are California, Chamaeleon I, III, Musca, Lupus V, VI, Scorpius, Serpens, Corona Australis, Cepheus, and IC 5146 having the properties of active low-mass star-forming such as the Taurus cloud. The observing sensitivity of the Spitzer data is estimated to be about $L_{int}\;\geq\;5\times10^{-3}(d/140pc)^2\;L\odot$, a factor of 20 better than that of the Infrared Astronomical Satellite (IRAS). The observing data were processed by the c2d Legacy pipeline. As the criteria to select the VeLLOs, we slightly modified previous ones by Dunham et al. The most important criterion is a flux density at 70 micron that is directly converted to the internal luminosity. Also, we used additional criteria to remove the contamination of evolved stars and extragalaxies which have colors or SEDs very similar to YSOs. We identified a total of 64 new embedded VeLLO candidates with $L_{int}$ < $0.1(d/140pc)^2\;L\odot$, consisting of 8 in California, 15 in Chamaeleon-Musca, 13 in Scorpius-Lupus, 20 in Serpens, 3 in Corona Australis, 3 in Cepheus, and 2 in IC 5146. The classification of the spectral index (${\alpha}$) fitted to the shape of the Ks-24 micron SEDs shows most of VeLLO candidates (89%) are in types of Class I and Flat spectrum. We plot various diagrams based on their 2MASS-Spitzer bands colors and magnitudes to discuss properties of the VeLLOs. This search will lead us new adventure toward a future systematic study of the VeLLOs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1653-1659
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• 2013

In this paper, we propose a new ECAD software for efficiently analyzing and debugging of digital architecture implemented in Verilog HDL or VHDL codes. This software firstly elaborates HDL codes so as to extract internal architecture structure, then generates several graphical aids such as hierarchical schematics by applying placement and routing algorithm, object tree to show configuration of each module, instance tree to show hierarchical structure of instances, and SPD (Signal Propagation Diagram) to show internal interconnections. It is more important function that same objects in different views(HDL codes, object tree, instance tree, SPD, waveform etc.) can be highlighted at the starting any object. These functions are sure to improve efficiency of manual job to fix bugs or to analyze HDL codes.

• Journal of The Korean Astronomical Society
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• v.39 no.4
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• pp.107-114
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• 2006

We conducted an analysis of a selected region from the FCRAO $^{12}CO$ Outer Galaxy Survey. The selected region is located between galactic longitude $117^{\circ}$ and $124^{\circ}$ with the velocity of -23 km $s^{-1}. Molecular clouds in this region show a peculiar velocity field, protruding from the Local Arm population. The selected region is divided into 7 clouds by spatial location. Though we were not able to identify the direct driving source for peculiar velocity of our target region, we find that there are several internal YSOs or star forming activities; there are many associated sources like an outflows, a high-mass protostellar candidate and $H_2O$ maser sources. We attribute the driving energy source to older generation of episodic star formation. Masses of main clouds(cloud 1-4) estimated using a conversion factor from $^{12}CO$ luminosity are larger than $10^4M_{\odot}$. Other components have a small mass as about $10^3M_{\odot}$. Among main clouds, cloud 2 and 4 seem to be marginally gravitational bound systems as their ratio of $M_{CO}$ to $M_{VIR}$ is about $2{\sim}3$, and the internal velocity dispersion is larger than the centroid velocity dispersion. Total mass estimated using a conversion factor from $^{12}CO$ luminosity is $7.9{\times}10^4M_{\odot}$.

• Physical Therapy Korea
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• v.27 no.1
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• pp.19-29
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• 2020

Background: Stretch-oriented home exercise programs are often used as treatments for patients with adhesive capsulitis; however, there is lack of research on home exercise programs to strengthen rotator cuffs. Objects: The aim of this study is to investigate the effect of home exercise programs for rotator cuff strengthening on pain, range of motion (ROM), disability level, and quality of life in patients with adhesive capsulitis. Methods: Twenty-two patients with adhesive capsulitis volunteered to participate in this study. The subjects were randomly divided into an experimental group (n = 11) and control group (n = 11). For the experimental group, manual therapy and home exercise programs for rotator cuff strengthening were applied for 6 weeks; for the control group, only manual therapy was applied for 6 weeks. Shoulder pain (quadruple visual analogue scale, QVAS), ROM, disability (shoulder pain and disability index-Korean version, SPADI), and quality of life (world health organization quality of life scale-Korean version, WHOQOL-BREF) were evaluated at baseline, after 3 weeks, and after 6 weeks of intervention. The changes in the measurement variables were analyzed by using repeated measure analysis of variance. Results: Significant differences were observed between the experimental group and control group in the QVAS; SPADI-pain scores; SPADI-disability scores; SPADI-total scores; flexion, abduction, internal and external rotation ROM of the glenohumeral joint; and WHOQOL-BREF total, overall, physical health, and psychological scores. All groups displayed statistically significant improvements as observed in the QVAS, SPADI, flexion, abduction, external and internal rotation ROM of the glenohumeral joint, and WHOQOL-BREF. Conclusion: Home exercise programs for rotator cuff strengthening had a positive impact on shoulder pain, shoulder ROM, disability level, and quality of life in patients with adhesive capsulitis. Therefore, we propose the use of home exercise programs for rotator cuff strengthening in the exercise rehabilitation of patients with adhesive capsulitis.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.4
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• pp.315-322
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• 2008

Valves in power plants are leaking internally by various damages including insertion of foreign objects on seat, seat crack, defects and fatigue crack of stem packing or welds etc. due to severe operating conditions such as high temperature and high pressure for extended period time. Acoustic emission(AE) technology should be applied in order to diagnose precisely and evaluate these valve internal leak. In this paper, results of studies which have accomplished in actual power plant are presented. We have analyzed background noise, AE signal level and frequency spectrum through laboratory tests on the basis of various actual conditions in power plant, and also have considered evaluation methods on the background noise, AE properties and the detectable minimum leak rate according to valve leak conditions through comparing with results of field tests in power plant. As a result of these studies, we conformed that evaluation of internal leak conditions including discrimination of leak or not, and the detectable minimum leak rate is possible, and also it is expected to contribute to safe operation and prevention of energy loss in power plants.

• Physical Therapy Korea
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• v.28 no.3
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• pp.186-193
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• 2021

Background: While the formal test has been used to provide a quantitative measurement of core stability, studies have reported inconsistent results regarding its test-retest and intraobserver reliabilities. Furthermore, the validity of the formal test has never been established. Objects: This study aimed to establish the concurrent validity and test-retest reliability of the formal test. Methods: Twenty-two young adults with and without core instability (23.1 ± 2.0 years) were recruited. Concurrent validity was determined by comparing the muscle thickness changes of the external oblique, internal oblique, and transverse abdominal muscle to changes in core stability pressure during the formal test using ultrasound (US) imaging and pressure biofeedback, respectively. For the test-retest reliability, muscle thickness and pressure changes were repeatedly measured approximately 24 hours apart. Electromyography (EMG) was used to monitor trunk muscle activity during the formal test. Results: The Pearson's correlation analysis showed an excellent correlation between transverse abdominal thickness and pressure biofeedback unit (PBU) pressure as well as internal oblique thickness and PBU pressure, ranging from r = 0.856-0.980, p < 0.05. The test-retest reliability was good, intraclass correlation coefficient (ICC1,2) = 0.876 for the core stability pressure measure and ICC1,2 = 0.939 to 0.989 for the abdominal muscle thickness measure. Conclusion: Our results provide clinical evidence that the formal test is valid and reliable, when concurrently incorporated into EMG and US measurements.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.71-79
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• 2023

Air ingress incidents are major safety accidents in very-high-temperature reactors (VHTRs). Air containing a high volume fraction of oxygen may cause severe oxidation of core components at the VHTR, especially for the significantly thin alloy tube wall in the intermediate heat exchanger (IHE). The research objects of this study are Inconel 617 and Incoloy 800H, two candidate alloys for IHE in VHTR. The air ingress accident scenario is simulated with high-temperature air flow at 950 ℃. A continuous oxide scale was formed on the surfaces of both the alloys after the experiment. Because the oxide scale of Inconel 617 has a loose structure, whereas that of Incoloy 800H is denser, Inconel 617 exhibited significantly more severe internal oxidation than Incoloy 800H. Further, Inconel 617 showed a significant decrease in ultimate tensile strength and plasticity after aging for 200 h, whereas Incoloy 800H maintained its tensile properties satisfactorily. Through control experiment under vacuum, we preliminarily concluded that serious internal oxidation is the primary reason for the decline in the tensile properties of Inconel 617.

• Tuberculosis and Respiratory Diseases
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• v.45 no.3
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• pp.565-573
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• 1998

Malignant pleural effusions are most commonly associated with lung cancers, however, it also can be resulted from breast cancers, ovarian cancers, stomach cancers and so on. According to the their histologic types, adenocarcinoma have been known as the most common cell type of malignant pleural effusions and squamous cell carcinoma is rare. We herein present incidences, clinical characteristics and survivals of malignant pleural effusions according to their cell types and primary diseases. The objects are 84 malignant pleural effusion patients diagnosed by pleural fluid cytologic examination or pleural biopsy from Jan. 1992 to May. 1997 in Seoul National University Hospital. A retrospective chart review on their histologic types, biochemical parameters and survivals is described. Among 84 patients, 52 were males and the other 32 were females with 1.6:1 of male and female ratio and their mean age was 57.6 years old. Common symptoms of them wele dyspnea, cough, sputum and pleuritic chest pain. The proportions of bloody nature of effusion, lymphocyte dominant pleural effusion, exudative effusions were 66%, 39% and 93%, respectively. They consisted of 54 cases of adenocarcinoma(33 cases of them were lung cancers), and 10 cases of squamous cell carcinoma (8 cases of them were lung cancers), 10 cases of malignant lymphoma, 8 cases of small cell lung cancer and a case of mesothelioma and leukemia. There was no differences in characteristics of effusions, clinical features and survivals between each histologic cell types. Analyzing them according to primary diseases, no difference except longer survivals in malignant pleural effusions from breast cancer than from other cancers was observed. In conclusion, considering the incidences of histologic types of lung cancers during same period (squamous cell carcinoma; 47%, adenocarcinoma; 33%, small cell lung cancer; 12% and large cell carcinoma; 2%), malignant pleural effusions more likely occurred in adenocarcinoma than other cell types of lung cancers and there was no significant difference of clinical characteristics between histologic types.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.177-179
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• 2012

We present Spitzer IRS spectroscopy of $CO_2$ ice toward 19 young stellar objects (YSOs) with luminosity lower than $1L_{\odot}$. Pure $CO_2$ ice forms only at elevated temperatures, T > 20 K, and thus at higher luminosities. Current internal luminosities of YSOs with L < $1L_{\odot}$ do not provide such conditions out to radii of typical envelopes. Significant amounts of pure $CO_2$ ice would signify a higher past luminosity. We analyze $15.2{\mu}m$ $CO_2$ ice bending mode absorption lines in comparison to the laboratory data. We decompose pure $CO_2$ ice from 12 out of 19 young low luminosity sources. The presence of the pure $CO_2$ ice component indicates high dust temperature and hence high luminosity in the past. The sum of all the ice components (total $CO_2$ ice amount) can be explained by a long period of low luminosity stage between episodic accretion bursts as predicted in an episodic accretion scenario. Chemical modeling shows that the episodic accretion scenario explains the observed total $CO_2$ ice amount best.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.391-394
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• 2005

In this paper, we present an approach that is able to reconstruct 3 dimensional metric models from un-calibrated images acquired by a freely moved camera system. If nothing is known of the calibration of either camera, nor the arrangement of one camera which respect to the other, then the projective reconstruction will have projective distortion which expressed by an arbitrary projective transformation. The distortion on the reconstruction is removed from projection to metric through self-calibration. The self-calibration requires no information about the camera matrices, or information about the scene geometry. Self-calibration is the process of determining internal camera parameters directly from multiply un-calibrated images. Self-calibration avoids the onerous task of calibrating cameras which needs to use special calibration objects. The root of the method is setting a uniquely fixed conic(absolute quadric) in 3D space. And it can make possible to figure out some way from the images. Once absolute quadric is identified, the metric geometry can be computed. We compared reconstruction image from calibrated images with the result by self-calibration method.