• Journal of Engineering Education Research
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• v.10 no.2
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• pp.19-43
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• 2007

The Korean Society for Engineering Education (KSEE) was founded in 1994, and the Journal of Engineering Education Research has published since 1998. The purpose of the study was to analyze the research methodologies and contents for all 126 papers which were published from 1998 to 2005. A statistical package SPSS(ver. 15.0) was used to analyze the coding data of all papers. The research contents were as follows: (1) A classification of the number of papers published according to year and researcher features (gender, institution, major field, number of authors, etc) was performed, (2) The analysis of research methodologies and contents of the papers published was performed, (3) Strategies to improve the quality of the journal were suggested by discussion from the analysis results. The results showed that the development research method was used most frequently, most papers were mode by major scholars of electrical and electronic engineering and scholars of Yonsei University made the most papers. In order to use the survey research method, the sampling methods were mainly used by total number, purposive, convenience, stratified sampling method, etc, questionnaire was used of 89.5%, descriptive statistics of frequency/% was used of 50%. To conduct the experimental research method, the models of nonequivalent groups posttest-only design and one-group pretest-posttest design were adopted, respectively. Finally, research strategies and new direction for improving the engineering education journal's papers at the section of discussion and suggestion were suggested.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.5
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• pp.436-441
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• 2009

A fiber optic sensor is prospective to be applied to structural health monitoring. Especially, a fiber Bragg grating(FBG) sensor is one of the most popular sensors for the structural health monitoring. The FBG sensor has several demodulation systems for tracking the shift of the Bragg wavelength. The dynamic bandwidth is dependent on the demodulation system. In this paper, the sensing mechanism is that the slope of the optical spectrum of FBG could be used as its sensitivity when the tunable laser shot the monochromatic laser wavelength at the highest slope point. In this technique, the high sensitivity is guaranteed even though the sensing range is limited. In an example of the application, the composite plate embedding a FBG sensor was manufactured by using an autoclave method and the above sensing mechanism was applied to the composite plate. Firstly, the natural frequencies of the plate were successfully measured by the FBG sensor during the impact hammer test. Secondly, a high-power speaker was used to force the plate to be vibrated at the specific frequency that was one of the natural frequencies. During the shaking, the FBG sensor measures the dynamic characteristics and ESPI was also used to measure the mode shape. From the two dynamic tests, the availability of the FBG sensor system and the ESPI was proven as a technique for measuring the dynamic characteristics of composite structure.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.485-495
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• 2001

It was investigated whether $Ca^{2+}$ and $K^+$ channels were involved in the inhibitory action of nitric oxide (NO) on the contractile and slow wave activity of guinea pig gastric antral circular muscle. The gastric antral circular muscle showed spontaneous phasic contraction and slow wave. NO donors, 3-morpholinosydnonimine hydrochloride (SIN-1, $0.01{\sim}100{\mu}M$) and S-nitroso-L-cysteine (CysNO, $0.001{\sim}10{\mu}M$), reduced not only the amplitude of phasic contraction but also that of slow wave in a concentration-dependent manner. Both the perfusion of $Ca^{2+}$-free solution and the administration of $Ni^{2+}$, a nonselective $Ca^{2+}$ channel blocker, reduced the phasic contraction as well as the amplitude and frequency of the slow wave. The effects of these treatments were similar to those of NO donors. Nifedipine ($10{\mu}M$), a specific L-type $Ca^{2+}$ channel blocker, abolished the phasic contraction and remarkably reduced the plateau of slow wave but had no profound effect on the upstroke of slow wave. In the whole-cell patch clamp mode, CysNO shifted the steady-state activation curve for L-type $Ca^{2+}$ current to the right and the steady-state inactivation curve to the left. Pretreatment of various $K^+$ channel blockers such as tetraethylammonium (1 mM), 4-aminopyridine (0.5 mM), glibenclamide (10 mM), apamin ($0.1{\mu}M$), and iberiotoxin ($0.1{\mu}M$) did not affect the inhibitory action of SIN-1. These results suggest that NO donors suppress mechanical and electrical activity of guinea pig gastric antral circular muscle by inhibition of L-type $Ca^{2+}$ channel rather than by activation of $K^+$ channels.

• Journal of Chest Surgery
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• v.23 no.1
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• pp.81-89
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• 1990

A total of 178 patients with primary lung cancer who had undergone complete resection of the tumor in combination with complete mediastinal lymphadenectomy were reviewed at the Department of Thoracic and Cardiovascular Surgery of Yonsei Medical Center from January 1980 through July 1989. Materials; 1. There were 45 men and 33 women ranging of age from 25 to 78 years with a mean age of 55.4 years. 2. Histological types were squamous carcinoma in 115 cases [64.6%] adenocarcinoma in 42 cases [23.6 %], bronchioloalveolar carcinoma in 9 cases [5.1%], large cell carcinoma in 8 cases [4.5 %] and small cell carcinoma in 4 cases [2.2%] Results were summarized as follows: 1. The size of primary tumor was not directly proportional to the frequency of mediastinal lymph node metastasis. [P =0.0567] 2. The histologic types of the primary tumor did not related to the incidence of mediastinal lymph node metastasis. [P >0.19] 3. The chance of mediastinal lymph node metastasis in the case with lung cancer located in right middle lobe[31.8%, N=22] and left lower lobe [31.4%, N=32] were the highest and the lowest was the one located in right lower lobe, while over all incidence of mediastinal lymph node metastasis in this series was 25.4 % [N=55]. 4. The rate of mediastinal lymph node metastasis without evidence of regional and hilar lymph node metastasis was 13%. [N=23] The chance of mediastinal lymph node involvement without N1 lymph node metastasis was 16.3 % [N=17] in both upper lobes and 8.2 % [N=6] in both lower lobes. It was statistically significant that the tumors in the upper lobes had greater chance of the mediastinal lymph node metastasis without N1 than the tumors in the lower lobes. 5. In this series majority of the patients with lung cancer the mediastinal lymph node metastasis from the tumor in each pulmonary lobes usually occurs via ipsilateral tracheobronchial and paratracheal lymphatic pathway. Especially the lung cancer located in lower lobes can metastasize to subcarinal, paraesophageal and inferior pulmonary ligamental lymph node through the lymphatic pathway of inferior pulmonary ligament. It can be speculated that in some cases of this series otherwise mediastinal lymph node metastasis can also occur with direct invasion to the parietal pleura and to the mediastinal lymph node via direct subpleural lymphatic pathway .

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.728-739
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• 2020

Using webometric big data, this study examines the diversity of online information sources about the novel coronavirus causing the COVID-19 pandemic. Specifically, it focuses on some 28 countries where confirmed coronavirus cases occurred in February 2020. In the results, the online visibility of Australia, Canada, and Italy was the highest, based on their producing the most relevant information. There was a statistically significant correlation between the hit counts per country and the frequency of visiting the domains that act as information channels. Interestingly, Japan, China, and Singapore, which had a large number of confirmed cases at that time, were providing web data related to the novel coronavirus. Online sources were classified using an N-tuple helix model. The results showed that government agencies were the largest supplier of coronavirus information in cyberspace. Furthermore, the two-mode network technique revealed that media companies, university hospitals, and public healthcare centers had taken a positive attitude towards online circulation of coronavirus research and epidemic prevention information. However, semantic network analysis showed that health, school, home, and public had high centrality values. This means that people were concerned not only about personal prevention rules caused by the coronavirus outbreak, but also about response plans caused by life inconveniences and operational obstacles.

• Journal of Broadcast Engineering
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• v.17 no.2
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• pp.374-387
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• 2012

In this paper, we implement a new hardware for finding the significant coefficients of a digital hologram and ciphering them using discrete wavelet packet transform (DWPT). Discrete wavelet transform (DWT) and packetization of subbands is used, and the adopted ciphering technique can encrypt the subbands with various robustness based on the level of the wavelet transform and the threshold of subband energy. The hologram encryption consists of two parts; the first is to process DWPT, and the second is to encrypt the coefficients. We propose a lifting based hardware architecture for fast DWPT and block ciphering system with multi-mode for the various types of encryption. The unit cell which calculates the repeated arithmetic with the same structure is proposed and then it is expanded to the lifting kernel hardware. The block ciphering system is configured with three block cipher, AES, SEED and 3DES and encrypt and decrypt data with minimal latency time(minimum 128 clocks, maximum 256 clock) in real time. The information of a digital hologram can be hided by encrypting 0.032% data of all. The implemented hardware used about 200K gates in $0.25{\mu}m$ CMOS library and was stably operated with 165MHz clock frequency in timing simulation.

• Reproductive and Developmental Biology
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• v.38 no.3
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• pp.115-121
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• 2014

Humulus japonicus is an ornamental plant in the Cannabaceae family. Although the mode of action of Humulus japonicus is not fully understood, a strong relationship was observed between anti-inflammatory and anticancer in some types of cells. Recent studies also have shown that Humulus japonicus possesses anti-inflammatory activities and may significantly improve antioxidant potential in Raw 264.7 macrophage cells. Thus, the aim of this study was evaluated the effect of Humulus japonicus extract on sperm motility and subsequent preimplantation developmental competence of the bovine embryos. After in vitro maturation, the oocytes with sperms were exposed in in vitro fertilization (IVF) medium supplemented with Humulus japonicus extract (0.01, 0.05, $0.1{\mu}g/mL$, respectively) for 1 day. In our results, exposure of IVF medium to Humulus japonicus extract did not affect sperm motility and percentage of penetrated oocytes but ROS intensity was significantly decreased by $0.01{\mu}g/mL$ compared with other groups (p< 0.05). Moreover, treatment with $0.01{\mu}g/mL$ of Humulus japonicus extract was higher the frequency of blastocyst formation than the any other groups (p<0.05). Otherwise, treatment with $0.01{\mu}g/mL$ of Humulus japonicus extract not increased the total cell number but reduced apoptotic-positive nuclei number. In conclusion, our results indicate that supplementation of Humulus japonicus extract in IVF medium may have important implications for improving early embryonic development in bovine embryos.

• The Journal of Engineering Geology
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• v.9 no.1
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• pp.31-43
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• 1999

This study aims to quantify the distribution characteristics of the fracture system for the numerical modeling of groundwater flow in the north-eastern area of Yosu peninsula. The study area is composed mainly of volcanic rocks and granite. The regional and site scale lineament in the range of magnitude Order 1 to Order 3 were analyzed from the geologic map, air-photograph and shaded relief map. The geometric parameter of Order 4 fracture system was acquired from the scanline survey on the ground surface. There is a similar trend in the preferred orientation between the regional lineament and the Order 4 fracture system except the Set 4 of Order 4 fracture system which is not prominent in the type. That is classified to three fracture sat of high dip angle and one of ow dip angle. From the lineament trend. The orientation of Order 4 fracture system has similar characteristics in each rock termination mode analysis, it is considered that the fracture system was developed systematically and sequentially from Set 1 to Set 4 Filling materials are distinct relatively in low dip angle set. The fracture spacing follows to lognoral distribution and the fracture frequency corrected by the modified Terzaghi correction ranges from 0.38 to 1.01 per mater in each fracture set. The fracture trace lenght also follows to lognormal distribution and ranges from 2.9m to 3.7m in each fracture set.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.579-588
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• 2017

The purpose of this study was to examine the defibrillation efficiency according to the defibrillator type among paramedics by making a comparative analysis of the chest compression pause time and defibrillation efficiency after providing simulation education. The subjects in this study were 15 paramedics who were selected from a provincial 119 safety center. The experiment was conducted using a single-group pretest-post test design from March 2 to August 31, 2016. The collected data were analyzed by SPSS WIN 21.0, and a frequency analysis was conducted. The findings of this study were as follows: First, there was a significantly greater decrease in the chest compression pause time during CPR after providing simulation education when semi-automated defibrillators were used than when manual paddles and manual pads were employed. Second, there was a statistically significant decrease in the performance time of defibrillation when semi-automated defibrillators were used than when manual paddles and manual pads were used. The findings of this study are expected to provide paramedics with simulation education on how to promptly read ECGs using the manual mode of a semi-automated defibrillator to help more patients revive and on how to facilitate their job enlargement.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.413-431
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• 1992

Gonadal development, fertilization and egg development in the maternal body and reproductive cycle of ovoviviparous rockfish, Sebastes inermis, were investigated histologically. Gonadosomatic index(GSI) of male and female were increased from September and reached maximum values in December. In the male, GSI decreased from January, but in the female maintained high values till February and decreased from March. Hepatosomatic index(HSI) was related to GSI conversely. In both sex, HSI increased from February and reached maximum in August as the gonad were degenerating and resting, and began to decrease from September as gonad were glowing. This ovoviviparous rockfish copulates in December. Fertilization with sperms maintained between ovulated oocytes in the ovary occurs in January mainly. Egg development in the ovarian cavity and discharging of hatched preiarva occurs from January to February. The reproductive cycle includes the successive stages: Growing(September), Mature (October-November), Ripe and Fertilization(Decembr-Janua), Egg development and Discharging of hatched larva(January-February), Degeneration and Resting(February-August). According to the frequency distribution of egg diameter and histological observation, the ovoviviparous rockfish discharged the prelarva at a time in a spawning season. The sexual maturation is first attained at 2 ages. All females and males reaches first maturity at body length of 17.1cm and 15.1cm respectively. The mean number of the embryos increased with the increase of the total length of female.