• Nuclear Engineering and Technology
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• v.25 no.2
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• pp.237-247
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• 1993

Activity ratio of two radioactive primary fission products which had sufficiently different half-lives was expressed as functions of cooling time and irradiation histories in which average burnup, irradiation time, cycle interval time and the dominant fissile material of the spent fuel were included. The gamma-ray spectra of 36 samples from 6 spent PWR fuel assemblies irradiated in Kori unit-1 reactor were obtained by a spectrometric system equipped with a high purity germanium gamma-ray detector. Activity ratio $^{l44}$Ce $^{l37}$Cs, analyzed from each spectrum, was used for the calculation of cooling time. The results show that the radioactive fission products $^{l44}$Ce and $^{l37}$Cs are considered as useful monitors for cooling time determination because the estimated cooling time by detection of activity ratio $^{l44}$Ce $^{l37}$Cs agreed well with the operator declared cooling time within relative difference of $\pm$5 % despite the low counting rate of the gamma-ray of $^{l44}$Ce (about 10$^{-3}$ count per second). For the samples with several different irradiation histories, the determined cooling time by modeled irradiation history showed good agreement with that by known irradiation history within time difference of $\pm$0.5 year. From this result, it would be expected to be possible to estimate reliably the cooling time of spent nuclear fuel without the exact information about irradiation history. The feasibility study on identification of and/or sorting out spent nuclear fuel by applying the technique for cooling time determination was also performed and the result shows that the detection of activity ratio $^{l44}$Ce $^{l37}$Cs by gamma-ray spectrometry would be usefully applicable to certify spent nuclear fuel for the purpose of safeguards and management in a facility in which the samples dismantled or cut from spent fuel assemblies are treated, such as the post irradiation examination facility.mination facility.

• Korean Business Review
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• v.19 no.1
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• pp.53-80
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• 2006

This research has been accomplished to build up the growth strategies of Kangwon district's small & medium-sized construction firms. For this purpose, we made an investigation of the present situation and status for existing regional small & medium construction firms by analyzing data. Based on the results from this study, the following growth strategies are suggested to gain their competitive advantages. Firstly, most of all, the role of the top manager is the most important factor since most of the top manager for the small & medium-sized construction firms coincide with the owner the firms. Secondly, the specialization strategy is to establish. Above all they concentrate their business capacities on core business. Then, this growth strategy should be based on the selective escalation of functions in order to maintain an appropriate level of construction works. Thirdly, the specialized skills and skilled workers are ensured for competitive advantages. For human resource development, they should train workers to be multi-functioned on the assumption the they could stay at firm until they wish to retire. Finally, the government must also spare no effort to encourage the small & medium-sized construction firms to build up it's competitive power and cultivate it's spontaneous generation power though the reformation of system related whit the small and medium construction industry.

• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.21-35
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• 2018

Since the introduction of MP3 players, CD recordings have gradually been vanishing, and the music consuming environment of music users is shifting to mobile devices. The introduction of smart devices has increased the utilization of music through music playback, mass storage, and search functions that are integrated into smartphones and tablets. At the time of initial MP3 player supply, the bitrate of the compressed music contents generally was 128 Kbps. However, as increasing of the demand for high quality music, sound quality of 384 Kbps appeared. Recently, music content of FLAC (Free License Audio Codec) format using lossless compression method is becoming popular. The download service of many music sites in Korea has classified by unlimited download with technical protection and limited download without technical protection. Digital Rights Management (DRM) technology is used as a technical protection measure for unlimited download, but it can only be used with authenticated devices that have DRM installed. Even if music purchased by the user, it cannot be used by other devices. On the contrary, in the case of music that is limited in quantity but not technically protected, there is no way to enforce anyone who distributes it, and in the case of high quality music such as FLAC, the loss is greater. In this paper, the author proposes an audio watermarking technology for copyright protection of high quality stereo music. Two kinds of information, "Copyright" and "Copy_free", are generated by using the turbo code. The two watermarks are composed of 9 bytes (72 bits). If turbo code is applied for error correction, the amount of information to be inserted as 222 bits increases. The 222-bit watermark was expanded to 1024 bits to be robust against additional errors and finally used as a watermark to insert into stereo music. Turbo code is a way to recover raw data if the damaged amount is less than 15% even if part of the code is damaged due to attack of watermarked content. It can be extended to 1024 bits or it can find 222 bits from some damaged contents by increasing the probability, the watermark itself has made it more resistant to attack. The proposed algorithm uses quantization in DCT so that watermark can be detected efficiently and SNR can be improved when stereo music is converted into mono. As a result, on average SNR exceeded 40dB, resulting in sound quality improvements of over 10dB over traditional quantization methods. This is a very significant result because it means relatively 10 times improvement in sound quality. In addition, the sample length required for extracting the watermark can be extracted sufficiently if the length is shorter than 1 second, and the watermark can be completely extracted from music samples of less than one second in all of the MP3 compression having a bit rate of 128 Kbps. The conventional quantization method can extract the watermark with a length of only 1/10 compared to the case where the sampling of the 10-second length largely fails to extract the watermark. In this study, since the length of the watermark embedded into music is 72 bits, it provides sufficient capacity to embed necessary information for music. It is enough bits to identify the music distributed all over the world. 272 can identify $4*10^{21}$, so it can be used as an identifier and it can be used for copyright protection of high quality music service. The proposed algorithm can be used not only for high quality audio but also for development of watermarking algorithm in multimedia such as UHD (Ultra High Definition) TV and high-resolution image. In addition, with the development of digital devices, users are demanding high quality music in the music industry, and artificial intelligence assistant is coming along with high quality music and streaming service. The results of this study can be used to protect the rights of copyright holders in these industries.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.2
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• pp.37-51
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• 2018

Recently, urban parks are required to actively participate with residents in order to strengthen social functions and maintain sustainable management. This study analyzed the formation process of volunteer resident groups (Chamsamo) in the neighborhood parks in which local residents can participate in an ongoing basis based on the solidarity of a daily living space. The important factors in the activation of resident activity are derived from 5 aspects including resources, local area, resident group capacity, resident group role, and public support. The results of the study are as follows. 1) Life-friendly resources: It was important to find life-friendly resources such as 'Chamsaem' in the park. The combined resources of continuous human activities provided various benefits to the residents. This has led to stronger attachment and community activities to continue to utilize attractive resources in the park. 2) Sharing Common Daily Spaces and Expansion: As the Chamsamo activities were centered around the neighborhood, the network of activists in the local community expanded. This led to continued resident interest and favorable participation as well as to the regional expansion of Chamsamo activities. 3) Park management as part of everyday life: Park management became a part of everyday life, and pleasant park management was facilitated by utilizing the talents of the residents, who carried out diverse activities and constantly streamlined their hard labor. 4) Chamsamo's Leadership Linking Residents and the Public Sector through Leading Park Management Activities: Chamsamo served as a middle leader in linking the public sector and its users. 5) Role and Support of the Public Sector: In order to be able to sustain the activities of residents, the government's willingness to support the resident-led activities of the park in planning and operating the public sector was required. In the public management system of the park, support for residents' activities such as financing, education, and consulting was necessary.

• KDI Journal of Economic Policy
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• v.13 no.2
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• pp.141-161
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• 1991

Resale price maintenance has long been employed in book distribution, perhaps longer than for any other product. Another unusual practice in the book trade that has proven to be quite durable in spite of its substantial cost in real resources is the returns policy. Publishers typically grant the right to return unsold books within a stipulated time for full credit against future orders. This paper investigates the functions and effects of resale price maintenance in the book trade, and argues that resale price maintenance and returns are substitute methods of providing the same economic function. Resale price maintenance can be used to compensate booksellers for initially stocking books with uncertain prospects and for providing a conduit through which manufacturers acquire information about consumer demand (market testing services). Permitting the return of unsold books for full credit places a floor under retail prices and transfers a considerable portion of the cost of introducing a new product line back to the publisher. Both reflect publishers' needs to have their books displayed. In the U.S. returns privileges were first proposed in 1913, roughly coincident with the Macy decision outlawing RPM. Publishers slowly granted return privileges, which become nearly universal by 1970. The decline in margins in recent years has been accompanied by an increase in returns as the return policy served to substitute for lost margins on successful titles as a methods of compensating full-line booksellers. In contrast, returns privileges are unusual in countries where price maintenance in books has been practiced. These observations are consistent with our analysis. In Korea, resale price maintenance of books is practiced under an exception to Korean antitrust law. The availability of effective price maintenance is likely to reduce the use of returns programs. Since consumers prefer to obtain books at outlets where they know the books are likely to be stocked rather than taking a chance on stores that carry a more limited line, it also provides a strong incentive for booksellers to expand. But the privilege of resale price maintenance should be confined to books which publishers want to be price maintained. Resale price maintenance and returns system differ in the transactions costs associated with inventory holding, and publishers' judgement on the comparative advantage of the two schemes should be honored. Publishers should also remain free to authorize sales at discount at any time not to impair the ability of booksellers to dispose of product variants that prove unpopular.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.650-659
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• 1999

Background/Aims: It is well recognized that all aerobic cells have the protective mechanisms in order to minimize the tissue damage induced by various reactive oxygen species(ROS). Thioredoxin peroxidase(TPX) which has been recently identified and characterized functions to convert peroxide to water. The protein is also found in various subtypes(TPX-A & B, MER5, HS22 and HORF-06) and is known to be ubiquitous in most human cells. Especially, ischemic brain injuries, partial hepatectomy and radiation induced DNA damages. In treating lung cancer, radiation therapy has a major place in the local control and the relief of symptoms, but radiation induced free radical injury and resulting pulmonary fibrosis has been the major drawback of the therapy. However, little is known about the protective mechanisms and biologic modulations against radiation-induced tissue damages. Methods: Eighteen mice were divided into six groups, 3 in each group, and fifteen had received 900cGy of radiation. The mice were sacrificed according to the pre determined time schedule; immediate, 1, 2, 3 and 6 weeks after irradiation. Extracts were made from the lungs of each mice, Western blot analysis of various subtypes of TPX were done after SDS-P AGE. Examination of H & E stained slides from the same irradiated specimens and the control specimens were also performed. Results: No difference in the intensity of the immunoreactive bands in the irradiated lung samples of the mice compared to the unirradiated control was observed regardless of the time intervals, although H & E examination of the sample specimens demonstrated progressive fibrotic changes of the irradiated lung samples. Conclusion: In conclusion, according to our data, it is suggested that various thioredoxin peroxidase subtypes and catalase which are known to be increased in many repair processes may not be involved in the repair of the radiation injury to the lung and subsequent fibrosis.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.187-196
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• 2010

Recently, people have been suffering from stress-related fatigue and psychological disorders. Most people depend on medicine for pain relief; many treat pain also through alternative medicine or replacement therapy. However, drug therapy has many side effects, including increased stress after the therapy. In comparison, alternative therapies such as massage and foot reflexology are less damaging to the body, and such therapies can be provided without physical or psychological discomfort. In this regard, the author had previously co-developed color foot reflexology, which combines the merits of color therapy and foot reflexology; color foot reflexology has been shown to have beneficial effects without undue pain. This study investigates the effects of color foot reflexology on the physiological response of the body by comparing the body’s response to the signal with that to the placebo. Healthy adult subjects were selected for the experiment, which was conducted under optimal experimental conditions and design. The results indicated that when stimulated, parasympathetic nerves increased in HRV and that blood pressure, pulse, body heat, peripheral blood flow were dramatically activated. However, the results for the placebo indicated minimal changes or irregular outcomes. The results provide strong evidence for the beneficial effects of the color foot reflexology instrument on the autonomic nervous system and on the physiological response of the body. Future research is warranted to verify the results of the current study by examining patients suffering from diseases and disorders arising from irregular physiological functions in the context of the foot.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.423-428
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• 2000

In 1997 when cloned sheep Dolly and soon after Polly were born, it had become head-line news because in the former the nucleus that gave rise to the lamb came from cells of six-year-old adult sheep and in the latter case a foreign gene was inserted into the donor nucleus to make the cloned sheep produce human protein, factor IX, in e milk. In the last few years, once the realm of science fiction, cloned mammals especially in livestock have become almost commonplace. What the press accounts often fail to convey, however, is that behind every success lie hundreds of failures. Many of the nuclear-transferred egg cells fail to undergo normal cell divisions. Even when an embryo does successfully implant in the womb, pregnancy often ends in miscarriage. A significant fraction of the animals that are born die shortly after birth and some of those that survived have serious developmental abnormalities. Efficiency remains at less than one % out of some hundred attempts to clone an animal. These facts show that something is fundamentally wrong and enormous hurdles must be overcome before cloning becomes practical. Cloning researchers now tent to put aside their effort to create live animals in order to probe the fundamental questions on cell biology including stem cells, the questions of whether the hereditary material in the nucleus of each cell remains intact throughout development, and how transferred nucleus is reprogrammed exactly like the zygotic nucleus. Stem cells are defined as those cells which can divide to produce a daughter cell like themselves (self-renewal) as well as a daughter cell that will give rise to specific differentiated cells (cell-differentiation). Multicellular organisms are formed from a single totipotent stem cell commonly called fertilized egg or zygote. As this cell and its progeny undergo cell divisions the potency of the stem cells in each tissue and organ become gradually restricted in the order of totipotent, pluripotent, and multipotent. The differentiation potential of multipotent stem cells in each tissue has been thought to be limited to cell lineages present in the organ from which they were derived. Recent studies, however, revealed that multipotent stem cells derived from adult tissues have much wider differentiation potential than was previously thought. These cells can differentiate into developmentally unrelated cell types, such as nerve stem cell into blood cells or muscle stem cell into brain cells. Neural stem cells isolated from the adult forebrain were recently shown to be capable of repopulating the hematopoietic system and produce blood cells in irradiated condition. In plants although the term$\boxDr$ stem cell$\boxUl$is not used, some cells in the second layer of tunica at the apical meristem of shoot, some nucellar cells surrounding the embryo sac, and initial cells of adventive buds are considered to be equivalent to the totipotent stem cells of mammals. The telomere ends of linear eukaryotic chromosomes cannot be replicated because the RNA primer at the end of a completed lagging strand cannot be replaced with DNA, causing 5' end gap. A chromosome would be shortened by the length of RNA primer with every cycle of DNA replication and cell division. Essential genes located near the ends of chromosomes would inevitably be deleted by end-shortening, thereby killing the descendants of the original cells. Telomeric DNA has an unusual sequence consisting of up to 1,000 or more tandem repeat of a simple sequence. For example, chromosome of mammal including human has the repeating telomeric sequence of TTAGGG and that of higher plant is TTTAGGG. This non-genic tandem repeat prevents the death of cell despite the continued shortening of chromosome length. In contrast with the somatic cells germ line cells have the mechanism to fill-up the 5' end gap of telomere, thus maintaining the original length of chromosome. Cem line cells exhibit active enzyme telomerase which functions to maintain the stable length of telomere. Some of the cloned animals are reported prematurely getting old. It has to be ascertained whether the multipotent stem cells in the tissues of adult mammals have the original telomeres or shortened telomeres.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.261-277
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• 2017

This study defines influencing sections as the part of the road section where passing vehicles are traveling with the lower speed compared to speed limit due to speed humps. The influencing section was divided into 3 parts; influencing section before the speed hump, interval section, and influencing section after the speed hump. This analysis focused on the changes of each part depending on installation types, vehicle types, and daytime or nighttime. For the interval section, especially, the ratio of distance traveled with lower speed than speed limit to interval section is defined as effective influencing section ratio to be analyzed. Vehicle speed profiles were collected with a speed gun to extract influencing section lengths. The survival analysis was applied and estimated survival functions are compared with each other by several statistical tests. As a consequence, the average length of influencing section on the 50m sequential speed humps was 75.3% longer during the deceleration than that of isolated speed hump, and 18.9% during the acceleration. The effective influencing section ratio for the 30m and 50m sequential speed humps had a small difference of 81.0% and 76.0% while the absolute values of the section that passing speed were less than the speed limit were longer on 50m sequential speed humps, each being 24.3m and 38.0m. Using the log rank test, it was evident that sequential speed humps were more effective to increase the length of influencing sections compared to the isolated speed hump. Vehicle type was the strong factor for influencing section length on the isolated speed hump, but daytime or nighttime was not the effective one. This research result can be used for improving the efficiency selecting the installation point of speed humps for road safety and estimating the standard of the distance between sequential speed humps.

• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.219-229
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• 2017

Forest road is an essential infrastructure for forest management such as the composition and management of forest resources, timber and forest byproduct production & transportation. It has recently been utilized forest recreation and forest sports as well as also forest pest control, forest fire prevention and evolution. When you build a forest road, the economic function in the forest is activated, so that it can result in the ripple effect of induced employment, value-added creation and production inducement. The purpose of this study is to analyze the impact caused by forest road construction occurring as the overall economy. For analysis it was applied to inter industry analysis method that is a method for analyzing the quantitative cross-correlation. The data were used in the Input-Output Tables In 2014, the Bank of Korea. When you build a forest road, economic effect due to the construction of the forest road is generated and economic effects are also generated due to the increase in the production of forest products after the construction of the forest road. Therefore, we will analyze the economic impact of the two effects. The estimated economic value of forest products, which is the economic effect of forest product cultivation, was calculated through some assumptions and the economic ripple effect was analyzed. The forest road construction sector is defined as land clearing and reclamation, and irrigation project construction and the forestry forest products sector is defined as the sum of raw timber, edible forest products and misc. forest products. In total, 32 sectors were classified, and except for the two sectors defined as forest road construction and forestry forest products, the remaining sectors were integrated according to the classification system of 30 integrated classifications of the Bank of Korea. As a result, the production inducement coefficient for forest construction was analyzed to be 2.767 and the production inducement coefficient for forestry forest products was analyzed to be 1.565. This means that 2,767 times the production of forest road construction investment is induced in the whole industry and the production of 1.562 times the amount of forestry forest products is caused by the whole industry as the production of forestry forest products increases. The value added inducement coefficient for forest road construction was 0.977 and the value added inducement coefficient for forestry forest products was 0.985. Forest road are essential infrastructure for forestry development and should be continuously invested because they are essential elements of timber production and forest byproduct production with functions such as forest management, forest recreation, forest sports, and town connection.