• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.197-203
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• 2016

In this paper, the dipole antenna that can control a beam steering were designed for attaching on LEO(Low Earth Orbit) small satellite. The proposed antenna was based on Yagi-Uda antenna. The parasitic element was proposed as a T-shape. Depending on the state of open or short at the end of a vertical element, we can choose a characteristic of the parasitic element with fixing a vertical element length of the parasitic element. Using this characteristic, we designed the director element and reflector element. The proposed antenna was designed to receive UHF 436.5 MHz. Antenna gain was chosen by link budget between one satellite and the other satellite or between the satellite and the ground station. By changing a vertical element length which is the largest variable that chooses an antenna characteristic, we confirmed that ${\lambda}/2$ length transformer has a result that improve 0.5 dB in comparison ${\lambda}/4$ length transformer from maximum gain direction. In production, we made an on/off switch composed of a diode, capacitor, and inductor control an open and short at the end of the parasitic element. As a result, the gain of antenna used in a link between one satellite and the other satellite had average 5.92 dBi. And the gain of antenna used in a link between the satellite and the ground station had average 0.99 dBi.

• Journal of the Korea Society of Computer and Information
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• v.17 no.5
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• pp.59-70
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• 2012

RSA-CRT is one of the commonly used techniques to speedup RSA operation. Since RSA-CRT performs its operations based on the modulus of two private primes, it is about four times faster than RSA. In RSA, the two primes are normally thrown away after generating the public key pair. However, in RSA-CRT, the two primes are directly used in RSA operations. This led to hardware fault attacks which can be used to factor the public modulus. The most common way to counter these attacks is based on error propagation. In these schemes, all the outputs of RSA are affected by the infected error which makes it difficult for an adversary to use the output to factor the public modulus. However, the error propagation has sequentialized the RSA operation. Moreover, these schemes have been found to be still vulnerable to hardware fault attacks. In this paper, we propose two new RSA-CRT schemes which are both resistant to hardware fault attack and support parallel execution: one uses common modulus and the other one perform operations in each prime modulus. Both proposed schemes takes about a time equal to two exponentiations to complete the RSA operation if parallel execution is fully used and can protect the two private primes from hardware fault attacks.

• Korean Journal of Social Welfare
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• v.57 no.3
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• pp.165-194
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• 2005

This study is to explore how TV drama describes divorce process by the reason of extramarital relationship in the drama. To explore this subject, 30 drama synopses delineating extramarital relationship were analyzed. The results revealed that most of the couples had difficulties in emotional relationship and communication. The couples relationship was described traditionally patriarchal: husbands showed their authorities and wives showed dependency on their husbands. The partners of extramarital relationship were the lovers before current marriage. The patterns of extramarital relationship included 'intention to look for vitality despite satisfying current marriage' for the husbands and 'intention to avoid dissatisfied current marriage temporally' or 'to maintain marriage despite dissatisfaction' for the wives. For those who married 6 years and longer, more extramarital relationship was accepted as a terminator of the marriage. And in many cases, the divorce dose not mean to maintain the relationship with extramarital partner but to collapse of trust in partner. The results imply that the social work needs to be more sensitive to middle-class couples' communication and relationship problems. This will lead to the development of the social work intervention program for the couples.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.277-284
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• 2020

Text mining is a representative method of big data analysis that extracts meaningful information from unstructured and large amounts of text data. Social media such as Twitter generates hundreds of thousands of data per second and acts as a one-person media that instantly and directly expresses public opinions and ideas. The traditional media are delivering informations, criticizing society, and forming public opinions. For this, we compare the responses of SNS with the responses of media on the issue of the termination of the Korea-Japan GSOMIA (General Security of Military Information Agreement), one of the domestic issues in the second half of 2019. Data collected from 201,728 tweets and 20,698 newspaper articles were analyzed by sentiment analysis, association keyword analysis, and cluster analysis. As a result, SNS tends to respond positively to this issue, and the media tends to react negatively. In association keyword analysis, SNS shows positive views on domestic issues such as "destruction, decision, we," while the media shows negative views on external issues such as "disappointment, regret, concern". SNS is faster and more powerful than media when studying or creating social trends and opinions, rather than the function of information delivery. This can complement the role of the media that reflects public perception.

• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.173-180
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• 1996

This paper briefly describes the KITSAT-1 and KITSAT-2 spacecrafts and presents the functions, calibration procedures and in-orbit results of the KITSAT-2 analog sun sensors have been flown as an experimental payload for the future mission. We have two constraints in their design: small size and very low power consumption due to the tight mass and power budget of the spacecraft. Two one-dimensional analog sun sensors are mounted on the top facet of the KITSAT-2 spaceraft. Each has $\pm$60 degrees of view angle and they cover 210 degree field of view in total as the 30 degree view angles are overlapped. Only the relative sun angle around the Z-axis (yaw-axis) and the spin rate of the spacecraft can be achieved as the one dimensional sun sensors are used and they are aligned with the Z-axis. The calibration formulae are obtained using the fifth order line fitting algorithm for each sun sensor on the ground and they are applied to the obtained in-orbit data. ASS-1 with silicon solar cells has maximum error of 1.5 degree and ASS-2 with silicon photocells manufactured at KAIST has maximum error of 0.5 degree except near 0 degree of sun ray incident anagle where random reflection of incident sun ray is maximum in orbit. The results are presented in chapter 4. The performance of each sun sensor and the possible mounting errors are stated in chapter 5.

• Journal of Korea Technology Innovation Society
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• v.20 no.2
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• pp.313-333
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• 2017

As science and technology advanced, specialized and massive, development through mutual cooperation or research based on patent licensing such as material transfer contract, technology transfer contract etc are actively taking place to minimize or separate the cost and risk of R&D. In R&D, such mutual work can enjoy the merit of division of labor by effectively allocating resources and manpower to accomplish its goal. Inevitably, however, there are also many possibilities of disputes regarding the ownership and use of intellectual property rights resulting from such mutual/post-studies, or inventions upgraded by using prior patents. The case reviewed by this paper is noticeable regarding the recent trend of upgraded inventions. In the case, a pharmaceutical company conducted tests/assessments on the complete technology of patent owned by a university on the premise of transferring the technology, and then terminated the technology transfer contract due to reasons of toxicity. The university then filed a damage claim suit against the company for infringing the contract. This is a dispute case betw een a university which developed a potential ingredient for new medicine and a pharmaceutical company which agreed to transfer and receive the technological later on. Regarding the upgraded inventions of source patents, this case has many implications on the protection of prior patents, research contract, and research security to protect the accomplishment of research. This paper reviews the subject ruling and the protection of upgraded patents and source technologies. As critical notes, the paper also summarizes the major issues of case ruling to observe the standard of ruling patent infringement related to the extortion of upgraded patents. Then, through the ruling of the case above, the paper suggests implications and future strategies.

• Journal of Chest Surgery
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• v.39 no.2 s.259
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• pp.117-126
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• 2006

Background: The purpose of this study is to describe the characteristics of malpractice claims related to hemopneumothorax and to identify the causes and potential preventability of such claims. Material and Method: A retrospective study was performed by reviewing the records in the Lawnb website and Lx CD-rom: the records on closed malpractice claims involving hemopneumothorax were abstracted from the files available for analysis. The records were reviewed and were analysed to determine the etiology of hemopneumothorax, patient age, results of lawsuit and indemnity payment, underlying diseases, cause of death or complications, and the factors associated with a successful defense. Result: Seven closed claim involving hemopneumothorax were founded in the data for malpractice. Three claims were supreme court decision, one was a high court decision and three claims were district court decision. The most common cause of death was tension pneumothorax. Four of which resulted in indemnity payments. Conclusion: While malpractice claims involving hemopneumothorax were uncommon, they resulted in a high rate and amount of indemnity payments. Claims are more common in pediatric patients. In case of iatrogenic hemopneumothorax, post-procedural X-ray can improve patient outcome and is also associated with decreased indemnity risks. Informed consent is also important.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.2
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• pp.133-139
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• 2001

In order to obtain fundamental data for estimation of fisheries resource by echo sounder, we carried out the measuring of dorsal aspect Target strengths for rock bream and dusky spinefoot fishes that were caught much around the Jeju Island and in South Sea of Korea. The appropriate equations share the common form. TS=A+20 log L, where TS is the average dorsal aspect target strength in decibels, L is the fish total length in centimeters, and the coefficient A is determined by a least mean squares regression analysis. For rock bream, the result is TS=-72.97+20 log L and, for dusky spinefoot it is TS=-63.16+20 log L And, we have investigated the bearing range of maximum dorsal aspect target strength for all of rock bream and dusky spinefoot by the echo sounder with transducer of which frequency is 200kHz. They are $-12^\circ$-$-21^\circ$and $-1^\circ$--8 espectively, when the fishes is swimming down to the bottom. The maximum dorsal target strengths are -41.50dB at -18 or rock bream and -30.69dB at $-6^\circ$for dusky spinefoot.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.174-181
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• 1988

A comparison was made the differences of growth and some yield components of two soybean ecotypes (summer and two autumn types) at different planting dates (15 April, 15 May, and 15 June) and also made the different patterns of dry matter accumulation of one summer type and two autumn types of soybeans at Agricultural Experiment Farm, College of Agriculture, Dankook University, Cheonan City, in 1987. [Planting date experiment] Days to emergence of four varieties were observed no difference. and, therefore, it was speculated that field observation of the difference of cold tolerence between varieties was difficult. Shortening rate of flowering clays as planting dates delayed was no different between two ecotypes, summer vs. autumn types of soybean. Summer types, DN82029-3 and ES18085-1, were observed not greater difference of days to maturity between early and late planting dates as compared with that of autumn types, Changyeobkong and Paldalkong. At late planting, summer types were observed more to hasten days to ripening due to high temperature in late growing season than that of autumn types. This caused to decrease somewhat greater rate of some yield componments, and finally yield as planting date delayed. As compared to autumn types, summer types, DN82029-3 and ES18085-1 showed longer stem height and lower airdry weight at late planting. [Dry matter accumulation pattern] Stem elongation after flowering of three varieties, DN82029-3, Changyeobkong and Danyeobkong, ranged 17 to 32 cm and increment of leaf area index 0.83-1.53. DN82029-3 reached 49 days faster in maximum total dry weight than that of autumn types, Changyeobkong and Danyeobkong. However. maximum total dry weight of DN82029-3 showed 50% to autumn types. At 15 May planting, summer type, day-neutrality, transfered faster into reproductive growth phase without enough growth of vegetative growth and also hastened ripening days, and thus lower dry matter accumulation and finally lower yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.497-502
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• 1997

A seed pelleting technique was developed for easy handling of small sesame seeds (Chinbaeckkae) and for direct seeding in field. The mixture of pelleting material, binder(sodium alginate) and seeds were dropped in 100mM CaCl$_2$ solution. Charcoal was appeared as a best material among all to make pellets with the characters of hardness, breakdown, destruction rate and germination percentage. Zeolite formed the hardest pellet seeds among the materials and 1~3 seeds contained in a pellet on the treatment of 87g of sesame seeds mixed in 1$\ell$ CaCl$_2$ solution was estimated optimum rate of seed mixure with few appearance of seedless pellet. The moisture absorption rate was greater in the order of peat＋charcoal > peat > charcoal > zeolite. Germination percentage of pelleted seeds with charcoal was the best and similar to that of common non-treated seeds. Germination percentage of pelleted seeds by sowing depth of exposing a quarter of pellet seeds on the surface of vermiculite germination test box and were 92％ in charcoal treatment and was the best among all released materials.