• Journal of the Korean Chemical Society
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• v.38 no.10
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• pp.753-762
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• 1994

Dephosphorylation of diphenyl- or isopropylphenyl-4-nitrophenylphosphinate (DPNPIN or IPNPIN) mediated by $OH^-$ or o-iodosobenzoate ion ($IB^-$) are relatively slow in aqueous solution. The reactions in CTAX micellar solutions are, however, very accelerated, because CTAX micelles can accommodate both reactants in their Stern layer in which they can easily react, while hydrophilic $OH^-$(or $IB^-$) and hydrophobic phosphinates are not mixed in water. Even though the concentrations (> $10^{-3}$ M) of $OH^-$(or $IB^-$) in CTAX solutions are much larger amounts than those ($6{\times}10^{-6}$ M) of phosphinates, the rate constants of the dephosphorylations are largely influenced by change of the concentration of the ions, which means that the reactions are not followed by the pseudo first order kinetics. In comparison to effect of the counter ions of CTAX in the reactions, CTACl is more effective on the dephosphorylation of DPNPIN (or IPNPIN) than CTABr due to easier expelling of $Cl^-$ ion by $OH^-$(or $IB^-$) ion from the micelle, because of easier solvation $Cl^-$ ion by water molecules. The reactivity of IPNPIN with $OH^-$(or $IB^-$) is lower than that of DPNPIN. The reason seems that the 'bulky' isopropyl group of IPNPIN hinders the attack of the nucleophiles. The mechanism of reaction of IPNPIN with IB- ion concluded as 'nucleophilic' instead of 'general basic' by a trapping experiment and a measured kinetic isotope effect.

• Journal of Korea Port Economic Association
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• v.34 no.1
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• pp.111-132
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• 2018

As China continues to evolve as a major economic power and the Free Trade Agreement (FTA) between the Republic of Korea and China was ratified on June 1, 2015, market volume between the two countries is expected to grow more rapidly. This study aims on improving the efficiency of car-ferry lines. We conducted two surveys- for shippers and forwarders of car-ferry companies, and container liners. The study analyzes the decision factors for delivery companies and their importance for shippers and forwarders of car-ferry companies and container liners. Based on analysis of prior studies on the competition for car-ferry companies and liners, three primary variables are selected-promptness, economics, and safety. The promptness variable consists of shipping time, loading/unloading time, and customs clearing time. The economic variable consists of marine transportation cost from a domestic harbor to China, loading/unloading cost in the harbor, and overland transport cost from the harbor to shippers inland. Finally, the safety variable consists of cargo damage rates, safety facilities, such as lashing and shoring, and punctuality of transportation time. The survey and AHP results show that the promptness, safety, and economics factors are 0.549, 0.309, and 0.142 in the shipper groups of car-ferry companies' category, respectively. It indicates that there is considerable difference in the importance of each factor. In contrast, the factors are 0.350, 0.348, and 0.302 in the forwarders category, which suggests that there is little difference in each factor's importance. As for shippers and forwarders of liners, the importance of each factor is found to be in the following order: economics, safety, and promptness.

• Clean Technology
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• v.17 no.2
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• pp.124-133
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• 2011

In addition to six substances regulated in EU RoHS including lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE), priority substances are identified in new RoHS II as hexabromocyclododecane (HBCDD), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP) and diethylhexyl phthalate (DEHP). In this study, 20 plastic samples were collected from 12 domestic electrotechnical companies and levels of four restricted substances were determined by gas chromatography-mass spectrometry, Among 20 parts that compose washer, refrigerator or microwave oven, HBCDD was detected in three samples of NBR material with the amount of 42~381 mg/kg while DBP and BBP was not detected in any samples collected respectively, implying that these substance may not be used widely in plastic materials for EEE. However, DEHP was detected in all samples of NBR, PP, PBT, EPDM and PVC materials with the amount of 42 up to 59,400 mg/kg that exceeds the limit value of 0.1 wt% (1,000 mg/kg). Presence of a restricted substance in polymer material makes a great negative influence on a number of final product. To cope with coming RoHS II as well as REACH, action not to use DEHP in plastic material or the relevant notification in case of REACH seems to be needed. Screening test of Arsenic compounds such as diarsenic pentaoxide, diarsenic trioxide, lead hydrogen arsenate, triethyl arsenate that are included in REACH SVHC was done by ICP measurement Arsenium was detected in four samples made of NBR and PBT materials in the level of 15~700 mg/kg. By considering the screening method used in this study, the amount of arsenium compounds in the thermistor made of PBT material has a high chance of exceeding the regulated limit value.

• The Korean Journal of Air & Space Law and Policy
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• v.22 no.1
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• pp.9-27
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• 2007

The purpose of this paper is to study about the legal system of the Inter-governmental Agreement on the International Space Station('IGA') which was signed on Jan 29,1998. This paper is divided into three main parts ; 1) a review of ISS, 2) the principal rules of IGA, 3) the legal system of IGA. First, the paper draws an outline of ISS by dealing with (1) the definition, characteristics, and functions of ISS, (2) the composition of ISS. Second, the paper explains the principal rules of IGA which include (1) the rule of 'Partnership' and (2) the rule of 'Peaceful Purpose'. Third, the legal system of IGA is studied by looking at five different aspects: (1) the registration system, (2) a general jurisdiction, criminal jurisdiction and a control of jurisdiction, (3) intellectual property rights and other rights beside intellectual property, (4) cross-waiver of liability and several elements in compensation of damages, (5) the dispute resolution. IGA contains new contents and applications of legal system which was not included in the former space law. Therefore IGA will work as a model law for international cooperation of space development. It is important for us to study the matter of ISS, because disputes on the ISS are left solely to contracting parties although IGA will regulate overall situations. The renewed IGA is even more important because all the space development is expected to take place on an international cooperation basis. On the basis of this paper, all the important parts of IGA is expected to be further studied so that the research can contribute to the establishment of the legal system of space development in Korea.

• Korean Journal of Construction Engineering and Management
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• v.19 no.2
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• pp.15-24
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• 2018

Despite the recognition of the need for productivity information and its importance, the feedback of productivity information is not well-established in the construction industry. Effective use of productivity information is required to improve the reliability of construction planning. However, in many cases, on-site productivity information is hardly management effectively, but rather it relies on the experience and/or intuition of project participants. Based on the literature review and expert interviews, the authors recognized that one of the possible solutions is to develop a systematic approach in dealing with productivity information of the construction job-sites. It is required that the new system should not be burdensome to users, purpose-oriented information management, easy-to follow information structure, real-time information feedback, and productivity-related factor recognition. Based on the preliminary investigations, this study proposed a framework for a novel system that facilitate the effective management of construction productivity information. This system has utilized Sketchup software which has good user accessibility by minimizing additional data input and related workload. The proposed system has been designed to input, process, and output the pertinent information through a four-stage process: preparation, input, processing, and output. The inputted construction information is classified into Task Breakdown Structure (TBS) and Material Breakdown Structure (MBS), which are constructed by referring to the contents of the standard specification of building construction, and converted into productivity information. In addition, the converted information is also graphically visualized on the screen, allowing the users to use the productivity information from the job-site. The productivity information management system proposed in this study has been pilot-tested in terms of practical applicability and information availability in the real construction project. Very positive results have been obtained from the usability and the applicability of the system and benefits are expected from the validity test of the system. If the proposed system is used in the planning stage in the construction, the productivity information and the continuous information is accumulated, the expected effectiveness of this study would be conceivably further enhanced.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.980-987
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• 2012

Nonpoint source pollution causes leaks and overtopping, depending on the state of the sewer network as well as aggravates the pollution load of the aqueous water system as it is introduced into the sewer by wash-off. According, the need for efficient sewer monitoring system which can manage the sewage flowrate, water quality, inflow/infiltration and overflow has increased for sewer maintenance and the prevention of environmental pollution. However, the sewer monitoring is not easy since the sewer network is built in underground with the complex nature of its structure and connections. Sewer decontamination mechanism as well as pipe network monitoring and fault diagnosis of water network system on system analysis proposed in this study. First, the pollution removal pattern and behavior of contaminants in the sewer pipe network is analyzed by using sewer process simulation program, stormwater & wastewater management model for expert (XP-SWMM). Second, the sewer network fault diagnosis was performed using the multivariate statistical monitoring to monitor water quality in the sewer and detect the sewer leakage and burst. Sewer decontamination mechanism analysis with static and dynamic state system results showed that loads of total nitrogen (TN) and total phosphorous (TP) during rainfall are greatly increased than non-rainfall, which will aggravate the pollution load of the water system. Accordingly, the sewer outflow in pipe network is analyzed due to the increased flow and inflow of pollutant concentration caused by rainfall. The proposed sewer network monitoring and fault diagnosis technique can be used effectively for the nonpoint source pollution management of the urban watershed as well as continuous monitoring system.

• Journal of Korean Society of Forest Science
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• v.39 no.1
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• pp.47-56
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• 1978

This study aimed to know difference in freezing resistance among different clonal seedlings or different seed source seedlings of Cryptomeria japonica which has been selected where extreme cold prevails in Korea and Japan. The freezing resistance of three 12-50 year old trees was also measured in the experiment. The freezing resistance was measured in different tissue parts: mainly leaf, cambiam and xylem, at three different collection dates in two different collection places during the winter of 1977-1978. The following results and discussions were made: 1. The clonal difference in freezing resistance of Cryptomeria japonica was $9^{\circ}$ to $15^{\circ}C$ in maximum according to the collection place. However, the clonal difference in freezing resistance was not related to the difference in climatic conditions where the parent tree have been growing. This impiled that the natural selection of cold resistant genes in Cryptomeria japonica has not reached its evolutional equilibrium yet since most of the Cryptomeria forest has been established by artificial regeneration. 2. The difference in freezing resistance among leaf, cambium and xylem was not apparent except that leaf of several clones showed higher freezing resistance than cambium or xylem when they collected at mid-winter. The least freezing resistant tissue part, thought its freezing resistance was not measure in all clones and all temperatures were appeared in the apical buds. The new shoot growth was observed in the next spring with being replaced by its dormant or adventitious bud growth when the apical bud was injured dy cold during winter. 3. The freezing resistance of leaf, cambium and xylem was shown high enough so that freezing resistance Cryptomeria clones in this experiment were supposed to be able to survive in cold winter conditions at the middle part of Korea. However, it was reported that the most susceptible tissue part to winter injury was the basal stem, but of which freezing resistance was not-measured in this experiment. Several silvicultural methods for prevention of Cryptomeria seedlings from cold damage were discussed in literature.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.3
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• pp.92-106
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• 2017

This paper examines the validity of issuing municipal bonds for land compensation of long-term unexecuted urban parks and greenbelts. Then it suggests that municipal bonds should be issued for compensation priority areas with high rising prices. By conducting correlation analysis and PLS(Partial Least Squares) regression for 32 long-term unexecuted urban parks and greenbelts, the factors were identified that affected 'rising prices of IAPLP(Individually Announced Public Land Price) after seven years'. According to the analysis results, Variable Importance in the Projection in PLS regression was higher in 'IAPLP of base year(1.919)' and 'Accumulated rising Rates of average IAPLP in the borough(1.176).' The implications of this study are as follows. In Seoul, the accumulated rising rates of average IAPLP over the past 12 years is higher than the accumulated interest rates for seven years of urban planning facility bonds, which means that IAPLP have risen more than the interest payments due to the issuance of municipal bonds. In addition, since the actual compensation is three times that of IAPLP, it is judged that the land price is actually much higher than the interest payments. This shows that issuing municipal bonds and preferentially compensating for areas like high rising land prices can increase the economic efficiency of the budget execution. Also, for economic efficiency of budget execution, it is necessary to propose an 'area with high IAPLP' or 'a part in the borough with high rising rate of average IAPLP,' which is expected to have a high rising land price as criteria for compensation priority areas. In the future, when issuing municipal bonds to compensate long-term unexecuted urban parks and greenbelts, variousresearch on financing for municipal bonds repayment should be conducted.

• The Korean Journal of Ecology
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• v.22 no.3
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• pp.169-179
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• 1999

The present study was undertaken to classify and describe the spring naturalized plant communities in old-Andong city by the methodology of the ZM school of phytosociology. As a result, the vegetation was classified into the six communities and two subcommunities: A. Bromus tectorum community A-a. Bromus japonicus subcommunity, A-b. Melica onoei subcommunity; B. Poa pratensis community; C. Rumex crispus community; D. Oenothera lamarckiana community; E. Ambrosia artemisiifolia var. eiatior community; F. Rumex conglomeratus community. The total taxa of the naturalized plant communities consisted of 31 families, 86 genera, 114 species and 13 varieties. Of which the taxa of the naturalized plant species consisted of 8 families, 21 genera, 25 species and 1 variety. The result of Bray-Curtis ordination revealed that the plots suveyed were arranged according largely to the vegetation units of' the communities. Also the interspecific affinity was examined by an analysis of interspecific association and the main component species in the communities were divided into two groups. The naturalized rate was higher in the communitise affected by strong human impacts, while was lower in the communities affected relatively less by human impacts. On the other hand the seasonal changes of the communities and the naturalized rate between the spring and the autumn were investigated. Many naturalized communities present in Spring were replaced by the other native ruderal communitues in the Autumn. The naturalized rate based on the dominance was largely decreased over from the spring to the Autumn.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.3
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• pp.327-336
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• 2011

Reported causes of mandibular nerve injury in relation to neuropathic pain in dentistry include extraction, dental implant surgery, oral and maxillofacial surgery, periodontal treatment, and root-canal therapy. This study analyzed the characteristics of pharmacologic management of neuropathy after root-canal therapy. 32 patients who complain of abnormal sensation or pain after root-canal therapy and were referred to Department of Oral Medicine and the Temporomandibular Joint and Orofacial Pain Clinic at the Dental Hospital of Yonsei University, Seoul, Korea from 2004 to 2011 enrolled in this analysis and improvement of symptom was evaluated after pharmacologic management. Thirty-two patients who had hypoesthesia or dysesthesia at the initial visit were analyzed(9 men, 23 women; mean age: 44 years). The causes of neuropathy were local anesthesia(46.9%), chemical trauma from the sealant in root-canal(25%), endodontic surgery(15.6%), and unknown causes(12.5%). Medications such as steroids, anticonvulsants, antidepressants, and analgesics were took for improvement of symptoms and titrated for a variety of period from 1 week to 11 months. It was found that neuropathy of the inferior alveolar nerve and the lingual nerve was in 25 and 7 patients. The improvement of neurosensory disturbance and no improvement after pharmacotherapy was in 21(66%) and 11(34%) patients respectively. The hypoesthesia and dysesthesia was improved 67% and 65% respectively. These results suggest that symptomatic improvement by pharmacologic management can be possible in patients with neuropathy after root-canal therapy. But improvement of symptoms was influenced by the causes and degree of nerve injury, the periods of pharmacotherapy, and the choice of treatment methods. So, further investigation is needed by quantitative measurement of more variables in more individuals.