• Journal of Korea Port Economic Association
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• v.28 no.1
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• pp.83-104
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• 2012

The main purpose of tramp ships in shipping markets is to produce operation profits by minimizing the running days in a contract of the voyage charterparty. It is an especially difficult task for the owners to earn operation profits in the present recessional shipping market. Tramp ships are moving towards globalization in order to look for a variety of cargoes, which are distinguished from the liners operating regularly as per the fixed time schedule. Tramp shipping, therefore, requires special attention every voyage to secure operation efficiency which comes from minimized sea and laytime in port. The laytime is allowed by owners but if the charterers use more laytime than that which is incorporated in the charterparty, then a compensation known as 'demurrage' must be paid to owners. Conversely if the time is shorter this is called 'despatch' and in this case the owners are paid. As the laytime issue in the voyage charter is somewhat delicate, it often causes much disputes between charterers and owners during the cargo handling in ports. This study focuses on the charterers' right and duty on the laytime which is usually applied for the benefit of the charterers. Reference is also made to English law cases to reinforce this study and the conclusion will make relevant suggestions for further research.

• Hwankyungkyoyuk
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• v.11 no.2
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• pp.130-143
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• 1998

This study was conducted as a preliminary step to establish a model for the practical application of environmental education related to food wastes collected from elementary school foodservices. Methods of treatment and present recycling status of food wastes in elementary schools in Kyonggido were surveyed. The consciousness of dieticians who have been serving for elementary school foodservices was also analyzed through the survey questions concerning environmental education for the reduction and recycling of food wastes. The results derived from this survey were as follows: The major portion of food wastes from elementary school foodservices was constituted with vegetables and soup, and an average amount of food wastes per day was highest in June and July. Therefore environmental education related to reduction of wastes was needed in the first semester of school terms, and the possible reduction of food wastes achieved through the proper planning of school foodservice menu was also needed. In most cases food wastes were collected and treated by animal growing farmers or composted by machines in school. In operating composting machines microorganism inoculant was mostly used but dieticians pointed out the problem of a nasty odor, insects, and high energy consumption. This situation means it has not been operated efficiently and suggests an efficiency problem of machine composting in elementary schools because composting itself is based on the aerobic digestion and high temperature fermentation which kills insects and harmful microorganisms. Elementary school dieticians in Kyonggido were aware that food wastes cause main pollution problem, and that food wastes are valuable resources which can be recycled, and recycling of food wastes is inevitable. But more than half of the schools surveyed have not been reused food wastes in school, so a proper model for recycling and reuse of food wastes in school grounds was thought to be needed. Environmental education programs related to food wastes have not been peformed in more than half of the schools surveyed. It was concluded that the following three plans will be helpful to reduce school food wastes. First, environmental education should be enforced, second, teachers' and dieticians' intensive teaching concerning food wastes should be needed, and finally establishment of a model for recycling and reuse of food wastes in school grounds and its application to environmental education would offer a valuable field experience to school students.

• Korean Journal of Optics and Photonics
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• v.31 no.3
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• pp.142-147
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• 2020

In this paper, we report highly efficient second harmonic generation of continuous-wave Yb fiber lasers incorporating a periodically poled LiTaO₃ device (MgO:PPSLT) as a frequency converter. The seed laser output from a Yb fiber master oscillator using a Fabry-Perot feedback cavity was amplified in a Yb fiber amplifier stage, yielding 28.5 W of linearly polarized output at 1064 nm in a beam with beam quality, M², of ~1.07. Second harmonic generation was achieved by passing the laser beam through MgO:PPSLT. Under optimized conditions, we obtained 11.1 W of green laser output at 532 nm for an incident signal power of 25.0 W at 1064 nm, corresponding to a conversion efficiency of 44.4%. The detailed investigation to find the optimized operating conditions and prospects for further improvement are discussed.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.6
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• pp.107-119
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• 2016

Currently, 230 domestic tourist destinations have been designated, established, and operated in accordance with the Tourism Promotion Act. According to the results of preceding research, more than 30% of them have been getting into the stagnation or decline stage. This is becoming a burden to local governments operating and managing tourist destinations, making it necessary to seek resolution measures. Thus, this study determined the activation elements of stagnant/declined tourist destinations regeneration to deal with problems of domestic stagnant or declined tourist destinations and also to regenerate rational and sustainable tourist destinations. This study conducted a survey with experts based on causes for stagnation and decline of domestic tourist destinations suggested by preceding research. Based on the survey results, the activation elements of stagnant/declined tourist destinations regeneration were drawn through the Delphi Technique and Analytic Hierarchy Process. And then the priority and weight of the drawn activation elements of stagnant/declined tourist destinations regeneration were drawn for the sake of reasonable project progress of tour site regeneration. In the results of the analysis, as activation elements of stagnant/declined tourist destinations regeneration, a total of seven upper-attributes, 23 sub-attributes, and 66 detailed-elements were drawn. It would be possible to raise the efficiency of projects and rational decision-making when executing future tourist destinations regeneration projects by using the activation elements drawn. Also, the drawn elements could be applied to the actual tourist destinations regeneration projects as measures for the stagnant/declined domestic tourist destinations' contribution to the vitalization of local economy based on sustainability, prohibition of thoughtless development of domestic tourism projects, and also efficient use of tourism resources.

• Clean Technology
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• v.19 no.4
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• pp.370-378
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• 2013

This review has shown the capability of MOFs and ZIFs materials to adsorb $CO_2$ under typical PSA temperatures and pressures. The usual operating conditions are adsorption temperatures of $15{\sim}40^{\circ}C$ and adsorption pressures of 4~6 bar based on numerous PSA processes which are widely employed in gases industry for adsorptive separation of $CO_2$. The extent of $CO_2$ adsorption on the microporous materials depends on the metal species and organic linkers existing in the frameworks. The pore size and the surface area, and the process variables are the key parameters to be associated with the efficiency of the adsorbents, particularly adsorption pressures if other variables are comparable each other. The MOFs and ZIFs materials require high pressures greater than 15 bar to yield significant $CO_2$ uptakes. They possess a $CO_2$ adsorption capacity which is very similar to or less than that of conventional benchmark adsorbents such as zeolites and activated carbons. Consequently, those materials have been much less cost-effective for adsorptive $CO_2$ separation to date because of very high production price and the absence of commercially-proven PSA processes using such new adsorbents.

• Fire Science and Engineering
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• v.29 no.2
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• pp.79-83
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• 2015

The fire accident is a representative type of disaster that can largely impact on business. Therefore, precautionary measures and rapid initial response is very important when a disaster occurs. The storage of porous combustibles is inevitable in coal yard, plywood processing industry, and others that are currently operating. Initial fire fighting of fire and identifying the ignition point in such a porous combustible storage space are so difficult that if the initial response is failed, being led to deep-seated fire, surface fire is likely to result in secondary damage. In addition, deep-seated fire can cause personal injuries and property damage due to a large amount of toxic gases and reignition. Therefore damage reduction measures is required around the storage space to handle a porous flammable. Improving the penetration performance of the concentration of the surfactant is carried out as underlying study, which is about an deep-seated fire extinguishing efficiency augmentation when using wetting agents. The porous materials used in the experiments is radiata pine wood flour, which occupies more than 75% of the domestic wood market. Fire fighting water is selected as Butyl Di Glycol (BDG), which is being used for infiltration extinguishing agent, and the experiment was carried out by producing a standard solution. The experiment was carried out on the basis of the Deep-Seated Fire Test of NFPA 18. The amount of watering, porous material to the internal amount of penetration, and runoff measurement out of the porous material was conducted. According to experimental results, as the surface tension is reduced, the surfactant concentration macroscopic penetration rate decreases, but infiltration to a porous material is shown to have growth characteristics.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.4
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• pp.91-97
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• 2008

The objective of this research is to investigate the effect of the addition of granular activated carbon (GAC) and granular sludge on the performance of upflow anaerobic sludge blanket (UASB) reactors for treating leachate. For the control reactor, sludge obtained from an anaerobic digester was used as a seed material. On the other hand, GAC and granular sludge were incorporated with the seed sludge in the GAC reactor and the Granule reactor, respectively. The shortest acclimation period was observed in the Granule reactor. The GAC reactor also gave comparable performance to the Granule reactor at the beginning of operation. However, as the adsorptive capacity of GAC was exhausted, the effluent COD concentration increased gradually. Once the systems were stabilized, the GAC reactor showed slightly better results than the other two reactors in terms of chemical oxygen demand (COD) removal. COD removal in all reactors was more than 90% at hydraulic retention time of 1.0 day. Furthermore, GAC reactor showed little variation in COD removal rate and remained at 95% with organic loading rate (OLR) of 4.0 to $8.2kg\;COD/m^3.d$. Initial operating period was reduced by the addition of granular sludge, while the treatment efficiency was enhanced by the addition of GAC.

• Journal of the Korean association of regional geographers
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• v.13 no.6
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• pp.674-694
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• 2007

Recently private procurement projects for urban infrastructure have been emphasized and introduced by government(both central and local) as an important method to supplement public budget shortage and to improve creativity and efficiency in its construction and operation, and hence to promote regional development. But these private procurement projects seem to be implemented under the neoliberal condition of urban policy for private capital to extend its sphere of investment and to ensure its opportunity of profit. Such private procurement projects for urban infrastructure have been legislated and widely applied since 1994 in S. Korea, but in recent years they have triggered out a variety of serious problems. In results of this study on the private procurement for construction and operation of Burnan Road in Daegu, it can be pointed out, it has led serious problems such as overestimation of traffic volume in plan, over-appropriation of construction cost and appurtenant business, irYational operation and account of the operating firm, problem in refinancing and change in contents of practical agreement, and over-compensation of minimum operation revenue. Some measures that can be considered as alternatives to resolve those problems and to operate more rationally the Buman Road include those of increasing traffic revenues, of reducing supports of public financing, and withdrawal of (part or whole of) operational right from the private firm.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.752-756
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• 2006

The independent anoxic reactor was introduced in biological aerated filters as the regulation of water quality requirement, especially total nitrogen, had been strengthened. The process studied in this work was upflow $Biobead^{(R)}$ process which was used commercial invented for removal of organic materials and nitrification. For the purpose of evaluating the independent anoxic reactor, PCR-DGGE, of the molecular biological methods, was performed. Two types of nitrite reductase genes were selected. One is nirS represented cytocrome $cd_1$ nitrite reductase gene and the other is nirK represented Cu-containing nitrite reductase gene. Denitrifier community in the independent anoxic reactor was analyzed with PCR-DGGE using these two denitrifying functional genes. As the result of the PCR, only nirS gene was detected between nirS and nirK. With the result of the DGGE, specific bands became strong, as the operating days were longer, nitrate loading rate was increased. otherwise those of the initial activated sludge showed various bands. In the consequence of the sequence of DGGE bands, various denitrifiers were sequenced in the initial activated sludge, while specific denitrifiers like alcaligenes faecalis were predominant in the anoxic reactor. Consequently, introduction of the independent anoxic reactor made it possible to achieve 96% denitrification efficiency, and was proper for the modification of BAF process.

• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.667-676
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• 2016

The purpose of study was to determine the differences in organizational culture between social enterprises and commercial enterprises and assess the impact on organizational performance in Korea. Main results are as follows. First, Social enterprises employ a lot of low-imcome women and the elderly worker. Second, rational culture is high in profit businesses, but cultural group is high in social enterprises. In commercial enterprise, productivity and efficiency, planning and goal setting, assessing goals and looking for the evaluation of the performance are important. and in social enterprise, affinity and participation, employees individual development and group morale and cohesion, emphasis on mutual cooperation and trust are important. In addition, both social performance and economic performance, social enterprises are higher than in commercial enterprises. Social enterprises are operating transparently based on workers participation and understanding is expected that economic performance is also highly recognized. Third, social performance is higher development and group culture are higher in commercial enterprises, and development, group and hierarchy culture are higher in social enterprises. Economic performance is higher reasonal culture is lower in commercial enterprises, and group culture is higher in social enterprises. Therefore, the social enterprise workers are recognizing social and economic performance are higher than commercial enterprise workers. In short, social enterprises is making discriminatory organizational culture, and this is contributing to achieving organizational performance.