• Journal of Intelligence and Information Systems
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• v.20 no.4
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• pp.107-120
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• 2014

This study proposes a novel recommender system using the structural hole analysis to reflect qualitative and emotional information in recommendation process. Although collaborative filtering (CF) is known as the most popular recommendation algorithm, it has some limitations including scalability and sparsity problems. The scalability problem arises when the volume of users and items become quite large. It means that CF cannot scale up due to large computation time for finding neighbors from the user-item matrix as the number of users and items increases in real-world e-commerce sites. Sparsity is a common problem of most recommender systems due to the fact that users generally evaluate only a small portion of the whole items. In addition, the cold-start problem is the special case of the sparsity problem when users or items newly added to the system with no ratings at all. When the user's preference evaluation data is sparse, two users or items are unlikely to have common ratings, and finally, CF will predict ratings using a very limited number of similar users. Moreover, it may produces biased recommendations because similarity weights may be estimated using only a small portion of rating data. In this study, we suggest a novel limitation of the conventional CF. The limitation is that CF does not consider qualitative and emotional information about users in the recommendation process because it only utilizes user's preference scores of the user-item matrix. To address this novel limitation, this study proposes cluster-indexing CF model with the structural hole analysis for recommendations. In general, the structural hole means a location which connects two separate actors without any redundant connections in the network. The actor who occupies the structural hole can easily access to non-redundant, various and fresh information. Therefore, the actor who occupies the structural hole may be a important person in the focal network and he or she may be the representative person in the focal subgroup in the network. Thus, his or her characteristics may represent the general characteristics of the users in the focal subgroup. In this sense, we can distinguish friends and strangers of the focal user utilizing the structural hole analysis. This study uses the structural hole analysis to select structural holes in subgroups as an initial seeds for a cluster analysis. First, we gather data about users' preference ratings for items and their social network information. For gathering research data, we develop a data collection system. Then, we perform structural hole analysis and find structural holes of social network. Next, we use these structural holes as cluster centroids for the clustering algorithm. Finally, this study makes recommendations using CF within user's cluster, and compare the recommendation performances of comparative models. For implementing experiments of the proposed model, we composite the experimental results from two experiments. The first experiment is the structural hole analysis. For the first one, this study employs a software package for the analysis of social network data - UCINET version 6. The second one is for performing modified clustering, and CF using the result of the cluster analysis. We develop an experimental system using VBA (Visual Basic for Application) of Microsoft Excel 2007 for the second one. This study designs to analyzing clustering based on a novel similarity measure - Pearson correlation between user preference rating vectors for the modified clustering experiment. In addition, this study uses 'all-but-one' approach for the CF experiment. In order to validate the effectiveness of our proposed model, we apply three comparative types of CF models to the same dataset. The experimental results show that the proposed model outperforms the other comparative models. In especial, the proposed model significantly performs better than two comparative modes with the cluster analysis from the statistical significance test. However, the difference between the proposed model and the naive model does not have statistical significance.

• Progress in Medical Physics
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• v.19 no.4
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• pp.263-268
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• 2008

The application of a respiratory gated radiotherpy method to the lung radiation surgery was evaluated compared with the conventional method in which the whole tumor motion range is considered in the delineation of PTV (Planning target volume). The four dimensional CT simulation images were acquired for the five NSCLC (Non-small cell lung cancer) patients for radiation surgery. The respiratory gated plan was prepared with the 50% phase CT images and the conventional method was planned based on the ITV (Internal target volume) which include all the target volumes created in each phase CT images within a whole respiratory period. The DVH (Dose volume histogram) of OAR (Organ at risk) which calculated in each method was compared for the evaluation of the plan properness. The relative decrease of OARs' DVH were verified in the application of respiratory gated method. The average decrease rate were $16.88{\pm}9.97%$ in the bronchus, $34.13{\pm}19.15%$ in the spinal cord, $28.42{\pm}18.49%$ in the chest wall and $32.48{\pm}16.66%$ in the lung. Based on these results, we can verified the applicability and the effectiveness of the respiratory gated method in the lung radiation surgery.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.3
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• pp.254-259
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• 2014

A pressurized heavy water reactor (PHWR) core has 380 fuel channels contained and supported by a horizontal cylindrical vessel known as the calandria, whereas a pressurized water reactor (PWR) has only a single reactor vessel. The pressure tube, which is a pressure-retaining component, has a 103.4 mm inside diameter ${\times}$ 4.19 mm wall thickness, and is 6.36 m long, made of a zirconium alloy (Zr-2.5 wt% Nb). This provides support for the fuel while transporting the $D_2O$ heat-transfer fluid. The simple tubular geometry invites highly automated inspection, and good approach for all inspection. Similar to all nuclear heat-transfer pressure boundaries, the PHWR pressure tube requires a rigorous, periodic inspection to assess the reactor integrity in accordance with the Korea Nuclear Safety Committee law. Volumetric-based nondestructive evaluation (NDE) techniques utilizing ultrasonic and eddy current testing have been adopted for use in the periodic inspection of the fuel channel. The eddy current testing, as a supplemental NDE method to ultrasonic testing, is used to confirm the flaws primarily detected through ultrasonic testing, however, eddy current testing offers a significant advantage in that its ability to detect surface flaws is superior to that of ultrasonic testing. In this paper, effectiveness of flaw detection and the depth sizing capability by eddy current testing for the inside surface of a pressure tube, will be introduced. As a result of this examination, the ET technique is found to be useful only as a detection technique for defects because it can detect fine defects on the surface with high resolution. However, the ET technique is not recommended for use as a depth sizing method because it has a large degree of error for depth sizing.

• Journal of Sericultural and Entomological Science
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• v.16 no.2
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• pp.99-109
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• 1974

These studies aimed to establishment of controlling measure of the bud blight of mulberry tree when intermediate cutting harvest in autumn. The results obtained as following. 1. Effect of chemicals a) Results of 1972 (1) Of the seventeen chemicals tested. according to in vitro, the mycelial growth of Gibberella lateritium f. sp. mori was highly inhibited by PTAB and Benlate. PTAB and Benlate were also highly effective under the conditions of pathogen inoculated to the piece of mulberry tree and fungicidal action of these chemicals were stronger than the others. (2) Topsin-M. organic fungicide and plant growth regulator were not effective to inhibition of mycelial growth. (3) The effectiveness of fungicides were reduced gradually as the time after treatment increased. PTAB and Benlate retained approximately 50 percent of the original activity even after 15 days. (t) Of the twelve chemicals tested in fold, Benlate combination of PTAB with Apion, Apion and PTAB were the most effective fungicides for the control of bud blight of mulberry tree. (5) There is a sigificant difference between the timing on spraying, but it is not greatly effective for the control of bud blight of mulberry tree. b) Results of 1975 (1) Of the ten chemicals tested, according to in vitro RH 893, combination of Benlate with TMTD and TMTD were the most effective to inhibition of mycelial growth, followed by Benlate and combination of Benlate with Topsin M. (2) Of the eleven chemicals tested, Benlate, combination of Benlate with Kinondu, combination of Benlate with Topsin-M and Topsin M were highly effective under the renditions of pathogen inoculated to the piece of mulberry tree. (3) Of the eleven chemical evaluation tests were conducted in 3 experiment fold of Seoul, Chuncheun and Pusan, Benlate, Topsin-M, Apion, TMTD. combination of Benlate with Topsin-M, combination of Benlate with TMTD, combination of Benlate with Apion were highly effective chemicals for the control of bud blight of mulberry tree. (4) There is no difference between the timing on the chemical spraying after intermediate cutting harvest mulberry tree in autumn. 2. Ecological Control. When the mulberry shoot were cut off one to two buds from the top of intermediate cutting from 15th to 30th on October, bud blight of mulberry tree was greatly reduced in next spring compared with the effective chemical spraying. 3. Economical analysis on the results of chemical and ecological tests. When the expenses of ecological control for bud blight of mulberry tree per one ha was 100. thats of chemical control was from 159 to 254 according to spraying machines.

• Journal of Food Hygiene and Safety
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• v.31 no.2
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• pp.74-84
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• 2016

Literacy on food additives of elementary school teachers (ET) and nutrition teachers (NT) could be influential factor on safe dietary education for school children. Therefore, the perceptions and information needs on food additives were surveyed from 351 elementary school teachers and nutrition teachers in metropolitan area of Korea, and the basic data for the promotion of risk communication on food additives among them were obtained. Compared to ET who consider 'taste' (39.1%) as the most important factor while purchasing food, NT considered 'safety' (68.1%) first (p < 0.001). Among the food labelling items, the level of understanding on food additives was the lowest both in ET (3.53) and NT (4.17), and NT showed better levels of understanding overall on food labels. Both ET and NT regarded hazardous factors of food as environmental pollutants, foodborne pathogens, and food additives in order, and tended to select 'no additives' or 'no artificial color' products while purchasing processed food. Although NT answered that they know all food additives had been passed the evaluation of safety and effectiveness tests (100%) and have standards of use (81.9%), majority of them (87.5%) believed the consumption of food additives are harmful on human health. ET (75.2%) also regarded food additives as dangerous materials. Above results suggested the necessity of proper and enough risk communication for both ET and NT. Both ET and NT wanted to have information on the safety or hazard of food additives. Most preferred media to get the information on food additives was TV (3.80) among ET and lecture (3.65) among NT. ET and NT trusted hospital, research institution/universities or the personnels working in these institutions as the provider of information on food additives. The result that the trust levels of ET and NT on government were relative low suggested the weakness of risk communication in Korean government. Although ET and NT answered that they do not trust mass media, their behaviors were affected by them such as reading food labels in ET (39.4%) and reducing the consumption of food additives in NT (50%). They also indicated mass media's problem of sensitive approach on food additives and asked the urgent reaction of government by providing sound information through experts on food additives. Above results revealed that ET and NT have different perceptions and information needs on food additives, therefore, proper risk communication should be provided for them to serve as dietary educators for elementary school children.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.377-382
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• 2009

Viral safety is an important prerequisite for clinical preparations of all biopharmaceuticals derived from plasma, cell lines, or tissues of human or animal origin. To ensure the safety, implementation of multiple viral clearance (inactivation and/or removal) steps has been highly recommended for manufacturing of biopharmaceuticals. Of the possible viral clearance strategies, Ultraviolet-C (UVC) irradiation has been known as an effective viral inactivating method. However it has been dismissed by biopharmaceutical industry as a result of the potential for protein damage and the difficulty in delivering uniform doses. Recently a continuous flow UVC reactor (UVivatec) was developed to provide highly efficient mixing and maximize virus exposure to the UV light. In order to investigate the effectiveness of UVivatec to inactivate viruses without causing significant protein damage, the feasibility of the UVC irradiation process was studied with a commercial therapeutic protein. Recovery yield in the optimized condition of $3,000\;J/m^2$ irradiation was more than 98%. The efficacy and robustness of the UVC reactor was evaluated with regard to the inactivation of human immunodeficiency virus (HIV), hepatitis A virus (HAV), bovine herpes virus (BHV), bovine viral diarrhea virus (BVDV), porcine parvovirus (PPV), bovine parvovirus (BPV), minute virus of mice (MVM), reovirus type 3 (REO), and bovine parainfluenza virus type 3 (BPIV). Non enveloped viruses (HAV, PPV, BPV, MVM, and REO) were completely inactivated to undetectable levels by $3,000\;J/m^2$ irradiation. Enveloped viruses such as HIV, BVDV, and BPIV were completely inactivated to undetectable levels. However BHV was incompletely inactivated with slight residual infectivity remaining even after $3,000\;J/m^2$ irradiation. The log reduction factors achieved by UVC irradiation were ${\geq}3.89$ for HIV, ${\geq}5.27$ for HAV, 5.29 for BHV, ${\geq}5.96$ for BVDV, ${\geq}4.37$ for PPV, ${\geq}3.55$ for BPV, ${\geq}3.51$ for MVM, ${\geq}4.20$ for REO, and ${\geq}4.15$ for BPIV. These results indicate that UVC irradiation using UVivatec was very effective and robust in inactivating all the viruses tested.

• Korean Security Journal
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• no.44
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• pp.7-35
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• 2015

The objective of this article is to inform and document the contemporary development of the private security industry in Queensland Australia, a premier holiday destination that provide entertainment for the larger region. The purpose of this review is to examine the comtemporary development of mandated licensing regimes regulating the industry, and the necessary reform agenda. The overall aim is threefold: first, to chart the main outcomes of the two-wave of reforms since the mid-'90s; second, to examine the effectiveness of changes in modes of regulation; and third, to identify the criteria that can be considered a best practice based on Button(2012) and Prenzler and Sarre's(2014) criteria. The survey of the Queensland regulatory regime has demonstrated that, despite the federal-guided reforms, there remain key areas where further initiatives remain pending, markedly case-by-case utilisation of more proactive strategies such as on-site alcohol/drug testing, psychological evaluations, and checks on close associates; lack of binding training arrangement for technical services providers; and targeted auditing of licensed premises and the vicinity of venues by the Office of Fair Trading, a licensing authority. The study has highlighted the need for more determined responses and active engagements in these priority areas. This study of the development of the licensing regimes in Queensland Australia provides useful insights for other jurisdictions including South Korea on how to better manage licensing system, including the measures required to assure an adequate level of professional competence in the industry. It should be noted that implementing a consistency in delivery mode and assessment in training was the strategic imperative for the Australian authority to intervene in the industry as part of stimulating police-private partnerships. Of particular note, competency elements have conventionally been given a low priority in South Korea, as exemplified through the lack of government-sponsored certificate; this is an area South Korean policymakers must assume an active role in implementing accredited scheme, via consulting transnational templates, including Australian qualifications framework.

• Geotechnical Engineering
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• v.12 no.4
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• pp.157-178
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• 1996

Current design methods for reinforced earth structures take no account of the magnitude of the strains induced in the tensile members as these are invariably manufactured from high modulus materials, such as steel, where straits are unlikely to be significant. With fabrics, however, large strains may frequently be induced and it is important to determine these to enable the stability of the structure to be assessed. In the present paper internal design method of analysis relating to the use of fabric reinforcements in reinforced earth structures for both stress and strain considerations is presented. For the internal stability analysis against rupture and pullout of the fabric reinforcements, a strain compatibility analysis procedure that considers the effects of reinforcement stiffness, relative movement between the soil and reinforcements, and compaction-induced stresses as studied by Ehrlich 8l Mitchell is used. I Bowever, the soil-reinforcement interaction is modeled by relating nonlinear elastic soil behavior to nonlinear response of the reinforcement. The soil constitutive model used is a modified vertsion of the hyperbolic soil model and compaction stress model proposed by Duncan et at., and iterative step-loading approach is used to take nonlinear soil behavior into consideration. The effects of seepage pressures are also dealt with in the proposed method of analy For purposes of assessing the strain behavior oi the fabric reinforcements, nonlinear model of hyperbolic form describing the load-extension relation of fabrics is employed. A procedure for specifying the strength characteristics of paraweb polyester fibre multicord, needle punched non-woven geotHxtile and knitted polyester geogrid is also described which may provide a more convenient procedure for incorporating the fablic properties into the prediction of fabric deformations. An attempt to define improvement in bond-linkage at the interconnecting nodes of the fabric reinforced earth stracture due to the confining stress is further made. The proposed method of analysis has been applied to estimate the maximum tensions, deformations and strains of the fabric reinforcements. The results are then compared with those of finite element analysis and experimental tests, and show in general good agreements indicating the effectiveness of the proposed method of analysis. Analytical parametric studies are also carried out to investigate the effects of relative soil-fabric reinforcement stiffness, locked-in stresses, compaction load and seepage pressures on the magnitude and variation of the fabric deformations.

• Journal of Environmental Policy
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• v.11 no.4
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• pp.3-37
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• 2012

In perspective of biodiversity conservation and protected areas (PAs), the aims of the study are to review the mid-long term national plans, which deal with national territory and environment in Korea, and to find out the way to improve this issue. Key issues were drawn by referring "Biodiversity 2011-2020 Strategic Targets" and "Protected Area Decision" in CBD CoP-10 and 7 National comprehensive or basic Plans were reviewed. Quoting Biodiversity 2011-2020 Strategic Target 5, "By 2020, the rate of loss of all natural habitats, including forests, is at least halved and where feasible brought close to zero, and degradation and fragmentation is significantly reduced", most of national plans included various methods such as "No Net Loss of Green", "No Net Loss of Wetlands", and so on. Regarding the target 11, "By 2020, at least 17% of terrestrial and inland water, and 10% of coastal and marine areas, ecologically representative and well connected systems of PAs and other effective area-based conservation measures, and integrated into the wider landscape and seascapes", 15% by 2015 was set up as a target of total PAs in Korea and 13% by 2015 or 2020 was set up as a target of coastal and marine PAs. CBD CoP-10 Decision X/31 (Protected Areas) invites parties to develop a national long-term action plan for the implementation of PoWPA and describes 10 issues that need greater attention. National action plan for the implementation of PoWPA doesn't be mentioned at any national plans even PoWPA. Regarding the 10 issues, most of issues were well reflected within various national plans, however there is still a need to improve the details and corelation between plans. Particularly, in terms of management effectiveness evaluation (MEE), there was no national plan to directly deal with MEE even though CBD invites parties to work towards assessing 60% of the total PAs by 2015. Based on the review results, below 4 items were suggested; (1)"The Comprehensive Plan of the National Territory" needs more attention on the Biodiversity Conservation and PAs, (2)Consider to establish "National PA System Plan" embedded into "the Comprehensive Plan of National Environment", (3)Establish a "National Action Plan for the implementation of PoWPA", (4)Improve the National Plans through linking with Biodiversity 2011-2020 Strategic Targets and relevant PA key issues.

• Journal of the Korean earth science society
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• v.34 no.7
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• pp.681-692
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• 2013

We aimed to evaluate the effectiveness of the Giggenbach bottle method and develop the related pretreatment and analytical methods using artificial fumarolic gases. The artificial fumarolic gases were generated by mixing $CO_2$, CO, $H_2S$, $SO_2$, $H_2$, and $CH_4$ gas streams with a $N_2$ stream sparged through an acidic medium containing HCl and HF, with their compositions varied by adjusting the gas flow rates. The resultant fumarolic gases were collected into an evacuated bottle partially filled with a NaOH absorption solution. While non-condensible gases such as CO, $H_2S$, and $CH_4$ accumulated in the headspace of the bottle, acidic components including $CO_2$, $SO_2$, HCl, and HF that were dissolved into the alkaline solution. Like other acidic components, $H_2S$ also dissolved into the solution, but it reacted with dissolved $Cd^{2+}$ to precipitate as CdS when $Cd(CH_3COO)_2$ was added. The non-condensible gases were analyzed on a gas chromatography. Then, CdS precipitates were separated from the alkaline solution by filtration, and they were pretreated with $H_2O_2$ to oxidize CdS-bound sulfide into sulfate. In addition, a portion of the solution was also pretreated with $H_2O_2$ to oxidize sulfite to sulfate. Following the pretreatment, the resultant samples were analyzed for $SO_4^{2-}$, $Cl^-$ and $F^-$ on an ion chromatography. In the meanwhile, dissolved $CO_2$ was analyzed on a total organic carbon-inorganic carbon analyzer without such pretreatment. According to our experimental results, the measured concentrations of the fumarolic gases were shown to be proportional to the gas flow rates, indicating that the Giggenbach bottle method is adequate for monitoring volcanic gas. The pretreatment and analytical methods employed in this study may also enhance the accuracy and reproducibility of the Giggenbach bottle method.