• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.11 no.2
• /
• pp.252-261
• /
• 2000

Objectivity：This study was conducted to examine the depression, self-concept, perception of stress & coping strategy in children with chronic physical illness. Methods：Two groups of participants were recruited for this study, 13 children with chronic illness in outpatient or inpatient treatment at Seoul National University Children's Hospital, and 13 nonpatient children. They were assessed using Korean form of the Piers-Harris Self-Concept Scale (PHSCS), Kovacs' Children's Depression Inventory(CDI) and three subscaleds('color how you feel' 'color how others make you feel' 'A children in the rain' of Children's Self-Report and Projective Inventory(CSRPI). Result：There were significant differences between the chronic ill children and the healthy children in scores of depression and self-concept. The chronicity ill children were more depressive and had very negative self-concept, and obtained significantly lower scores than the healthy children in the subscales of PHSCS, 'intellectual/school status' and 'popularity' Among three scales of CSRPI, there was no difference in 'color how you feel' and 'color how others make you feel' But there were significant differences in all items of 'A child in the rain'(quantity of raining, duration of raining, tool, and effectiveness). 'Duration of raining' correlated most negatively with PHSCS scores, and correlated positively with CDI scores. Conclusion：The children with chronic illness are more depressive and have very negative selfconcept. And they feel that the stresses are more permanent, but have no appropriate coping strategy. The results suggest that the chronic illness strongly affects the psychological and emotional adjustment of children(i.e. depression, peer relation, stress coping strategy).

• Journal of Intelligence and Information Systems
• /
• v.23 no.1
• /
• pp.127-141
• /
• 2017

Advances in Internet technologies and the proliferation of mobile devices enabled consumers to approach a wide range of goods and services, while causing an adverse effect that they have hard time reaching their congenial items even if they devote much time to searching for them. Accordingly, businesses are using the recommender systems to provide tools for consumers to find the desired items more easily. Association Rule Mining (ARM) technology is advantageous to recommender systems in that ARM provides intuitive form of a rule with interestingness measures (support, confidence, and lift) describing the relationship between items. Given an item, its relevant items can be distinguished with the help of the measures that show the strength of relationship between items. Based on the strength, the most pertinent items can be chosen among other items and exposed to a given item's web page. However, the diversity of the measures may confuse which items are more recommendable. Given two rules, for example, one rule's support and confidence may not be concurrently superior to the other rule's. Such discrepancy of the measures in distinguishing one rule's superiority from other rules may cause difficulty in selecting proper items for recommendation. In addition, in an online environment where a web page or mobile screen can provide a limited number of recommendations that attract consumer interest, the prudent selection of items to be included in the list of recommendations is very important. The exposure of items of little interest may lead consumers to ignore the recommendations. Then, such consumers will possibly not pay attention to other forms of marketing activities. Therefore, the measures should be aligned with the probability of consumer's acceptance of recommendations. For this reason, this study proposes a model-based approach to combine those measures into one unified measure that can consistently determine the ranking of recommended items. A regression model was designed to describe how well the measures (independent variables; i.e., support, confidence, and lift) explain consumer's acceptance of recommendations (dependent variables, hit rate of recommended items). The model is intuitive to understand and easy to use in that the equation consists of the commonly used measures for ARM and can be used in the estimation of hit rates. The experiment using transaction data from one of the Korea's largest online shopping malls was conducted to show that the proposed model can improve the hit rates of recommendations. From the top of the list to 13th place, recommended items in the higher rakings from the proposed model show the higher hit rates than those from the competitive model's. The result shows that the proposed model's performance is superior to the competitive model's in online recommendation environment. In a web page, consumers are provided around ten recommendations with which the proposed model outperforms. Moreover, a mobile device cannot expose many items simultaneously due to its limited screen size. Therefore, the result shows that the newly devised recommendation technique is suitable for the mobile recommender systems. While this study has been conducted to cover the cross-selling in online shopping malls that handle merchandise, the proposed method can be expected to be applied in various situations under which association rules apply. For example, this model can be applied to medical diagnostic systems that predict candidate diseases from a patient's symptoms. To increase the efficiency of the model, additional variables will need to be considered for the elaboration of the model in future studies. For example, price can be a good candidate for an explanatory variable because it has a major impact on consumer purchase decisions. If the prices of recommended items are much higher than the items in which a consumer is interested, the consumer may hesitate to accept the recommendations.

• Archives of design research
• /
• v.20 no.3 s.71
• /
• pp.151-162
• /
• 2007

How can new media devices and networks provide an effective response to the world's growing sector of cultural and historically-minded travelers? This study emerged from the question of how mobile handsets can change the nature of cultural and historical tourism in ubiquitous city environments. As wireless network and mobile IT have rapidly developed, it becomes possible to deliver cultural and historical information on the site through mobile handset as a tour guidance system. The paper describes the development of a new type of mobile tourism platform for site-specific cultural and historical information. The central objective of the project was to organize this cultural and historical walking tour around the mobile handset and its unique advantages (i.e. portability, multi-media capacity, access to wireless internet, and location-awareness potential) and then integrate the tour with a historical story and role-playing game that would deepen the mobile user's interest in the sites being visited, and enhance his or her overall experience of the area. The project was based on twelve locations that were culturally and historically significant to Korean War era in Busan. After the mobile tour game prototype was developed for this route, it was evaluated at the 10th PIFF (Pusan International Film Festival). After use test, some new strategies for developing mobile "edutainment content" to deliver cultural historical contents of the location were discussed. Combining 'edutainment' with a cultural and historical mobile walking tour brings a new dimension to existing approaches of the tourism and mobile content industry.

• The Korean Journal of Pharmacology
• /
• v.31 no.1 s.57
• /
• pp.1-9
• /
• 1995

The slow development of histopathological changes and long period required for stabilization of lesions have suggested that secondary injury processes exacerbate the effect of initial mechanical insult after traumatic spinal cord injury (SCI). The importance of glutamate receptors in the normal functions of spinal cord, in concert with the large body of evidence that points to their involvement in neurotoxicity due to both ischemic and traumatic insults to the CNS, suggested a probable role of glutamate receptors in secondary injury process after traumatic SCI. In order to investigate the involvement of excitatory amino acid in the secondary injury process after SCI, this study examined the effect of dextrorphan, a noncompetitive NMDA receptor antagonist, on the recovery of hindlimb function and the residual tissue at injury site following SCI. Locomotor function was assessed using open field test (21 point scale). At 8 weeks spinal cord tissue was examined using quantitative histopathologic technique. Prior to surgery female Long-Evans rats were adapted to the test environment. Rats received laminectomies (T9/T10), and spinal cord contusions (NYU impactor) were produced by a 10 gm weight dropped 25 mm. DXT (15 or 30 mg/kg, i.p.) or saline was injected 15 min before contusion. Behavioral testing resumed 2 days post-injury and continued twice a week for 8 weeks. No differences between DXT and saline groups were found for hindlimb function and sparing tissue at the lesion site. These results suggest that NMDA receptor might not be involved in secondary injury processes after traumatic SCI.

• Progress in Medical Physics
• /
• v.17 no.3
• /
• pp.131-135
• /
• 2006

A commercial ion chamber matrix was examined the characteristics and its performance for radiotherapy qualify assurance. The device was the I'mRT 2D-MatriXX (Scanditronix-Wellhofer, Schwarzenbruck, Germany). The 2D-MatriXX device consists of a 1020 vented ion chamber array, arranged in $24{\times}24cm^2$ matrix. Each ion chamber has a volume of $0.08cm^3$, spacing of 0.762 cm and minimum sampling time of 20 ms. For the investigation of the characteristics, dose linearity, output factor, short-term reproducibility and dose rate dependency were tested. In the testing of dose linearity. It has shown a good signal linearity within 1% in the range of $1{\sim}800$cGy. Dose rate dependency was found to be lower than 0.4% (Range: 100-600 Mu/min) relative to a dose rate of 300 Mu/min as a reference. Output factors matched very well within 0.5% compared with commissioned beam data using a ionization chamber (CC01, Scanditronix-Wellhofer, Schwarzenbruck, Germany) in the range of field sizes $3{\times}3{\sim}24{\times}24cm^2$. Short-term reproducibility (6 times with a interval of 15 minute) was also shown a good agreement within 0.5%, when the temperature and the pressure were corrected by each time of measurement. in addition, we compared enhanced dynamic wedge (EDW, Varian, Palo Alto, USA) profiles from calculated values in the radiation planning system with those from measurements of the MatriXX. Furthermore, anon-uniform IMRT dose fluence was tested. All the comparison studies have shown good agreements. In this study, the MatriXX was evaluated as a reliable dosimeter, and it could be used as a simplistic and convenient tool for radiotherapy qualify assurance.

• The Korean Journal of Air & Space Law and Policy
• /
• v.35 no.2
• /
• pp.375-402
• /
• 2020

The adoption and entering into force of the Registration Convention was another achievement in expanding and strengthening the corpus iuris spatialis. It was the fourth treaty negotiated by the member states of the UNCOPUOS and it elaborates further Articles 5 and 8 of the Outer Space Treaty(OST). The Registration Convention also complements and strengthens the Article 11 of the OST, which stipulates an obligation of state parties to inform the UN Secretary-General of the nature, conduct, locations, and results of their space activities in order to promote international cooperation. The prevailing purposes of the Registration Convention is the clarification of "jurisdiction and control" as a comprehensive concept mentioned in Article 5 8 of the OST. In addition to its overriding objective, the Registration Convention also contributes to the promotion and the exploration and use of outer space for peaceful purposes. Establishing and maintaining a public register reduces the possibility of the existence of unidentified space objects and thereby lowers the risk such as, for example, putting the weapons of mass destruction secretly into orbit. And furthermore it could serve for a better space traffic management. The Registration Convention is a treaty established to implement Article 5 of OST for the rescue and return of astronaut in more detail. In this respect, if OST is a general law, the Registration Convention would be said to be in a special law. If two laws conflict the principle of lex specialis will be applied. Countries that have not joined the Registration Convention will have to follow the rules concerning the registration of paragraph 7 of the Declaration by the United Nations General Assembly resolution 1721 (X V I) in 1961. UN Resolution 1721 (XVI) is essentially non-binding, but appears to have evolved into the norm of customary international law requiring all States launching space objects into orbit or beyond to promptly provide information about their launchings for registration to the United Nations. However, the nature and scope of the information to be supplied is left to the discretion of the notifying State. The Registration Convention is a treaty created for compulsory registration of space objects by nations, but in reality it is a treaty that does not deviate from existing practice because it is based on voluntary registration. With the situation of dealing with new problems due to the commercialization and privatization of the space market, issues related to the definition of a 'space object', including matter of the registry state of new state that purchased space objects and space debris matter caused by the suspension of space objects launched by the registry state should be considered as matters when amendments, additional protocols or new Registration Convention are established. Also the question of registration of a flight vehicle in the commercial space market using a space vehicle traveling in a sub-orbital in a short time should be considered.

• Tuberculosis and Respiratory Diseases
• /
• v.61 no.4
• /
• pp.366-373
• /
• 2006

Background: Paraquat is extremely toxic chemical material, which generates reactive oxygen species (ROS), causing multiple organ failure. In particular, paraquat leads to irreversible progressive pulmonary fibrosis. Exaggerated cell deaths exceeding the normal repair of type II pneumocytes leads to mesenchymal cells proliferation and fibrosis. This study examined the followings; i) whether or not paraquat induces cell death in lung epithelial cells; ii) whether or not paraquat-induced cell deaths are apoptosis or necrosis; and iii) the effects of N-acetylcysteine, dexamethasone, and bcl-2 on paraquat-induced cell deaths. Methods: A549 and BEAS-2B lung epithelial cell lines were used. The cell viability and apoptosis were evalluated using a MTT assay, Annexin V staining was monitored by fluorescence microscopy, The level of bcl-2 inhibition was examined by establishing stable A549 pcDNA3-bcl-2 cell lines throung the transfection of pcDNA3-bcl-2 with the mock. Results: Paraquat decreased the cell viability in A549 and BEAS-2B cells in a dose and time dependent manner. The Annexin V assay showed that apoptosis was the type of paraquat-induced cell death. Paraquat-induced cell deaths was significantly inhibited by N-acetylcysteine, dexamethasone, and bcl-2 overexpression. The cell viability of A549 cells treated with N-acetylcysteine, and dexamethasone on the paraquat-induced cell deaths were increased significantly by 10 ~ 20%, particularly at high doses. In addition, the cell viability of A549 pcDNA3-bcl-2 cells overexpressing bcl-2 was significantly higher than the untransfected A549 cells. Conclusion: Paraquat induces apoptotic cell deaths in lung epithelial cells in a dose and time dependent manner. The paraquat-induced apoptosis of lung epithelial cells might occur through the mitochondrial pathway.

• Korea Journal of Hospital Management
• /
• v.9 no.1
• /
• pp.66-94
• /
• 2004

The objective of this study is to examine how to maximize the efficiency of hospital management by minimizing the unit cost of hospital operation. For this purpose, this paper proposes to develop a model of the profit maximization based on the cost minimization dictum using the statistical tools of arriving at the maximum likelihood values. The preliminary survey data are collected from the annual statistics and their analyses published by Korea Health Industry Development Institute and Korean Hospital Association. The maximum likelihood value statistical analyses are conducted from the information on the cost (function) of each of 36 hospitals selected by the random stratified sampling method according to the size and location (urban or rural) of hospitals. We believe that, although the size of sample is relatively small, because of the sampling method used and the high response rate, the power of estimation of the results of the statistical analyses of the sample hospitals is acceptable. The conceptual framework of analyses is adopted from the various models of the determinants of hospital costs used by the previous studies. According to this framework, the study postulates that the unit cost of hospital operation is determined by the size, scope of service, technology (production function) as measured by capacity utilization, labor capital ratio and labor input-mix variables, and by exogeneous variables. The variables to represent the above cost determinants are selected by using the step-wise regression so that only the statistically significant variables may be utilized in analyzing how these variables impact on the hospital unit cost. The results of the analyses show that the models of hospital cost determinants adopted are well chosen. The various models analyzed have the (goodness of fit) overall determination (R2) which all turned out to be significant, regardless of the variables put in to represent the cost determinants. Specifically, the size and scope of service, no matter how it is measured, i. e., number of admissions per bed, number of ambulatory visits per bed, adjusted inpatient days and adjusted outpatients, have overall effects of reducing the hospital unit costs as measured by the cost per admission, per inpatient day, or office visit implying the existence of the economy of scale in the hospital operation. Thirdly, the technology used in operating a hospital has turned out to have its ramifications on the hospital unit cost similar to those postulated in the static theory of the firm. For example, the capacity utilization as represented by the inpatient days per employee tuned out to have statistically significant negative impacts on the unit cost of hospital operation, while payroll expenses per inpatient cost has a positive effect. The input-mix of hospital operation, as represented by the ratio of the number of doctor, nurse or medical staff per general employee, supports the known thesis that the specialized manpower costs more than the general employees. The labor/capital ratio as represented by the employees per 100 beds is shown to have a positive effect on the cost as expected. As for the exogeneous variable's impacts on the cost, when this variable is represented by the percent of urban 100 population at the location where the hospital is located, the regression analysis shows that the hospitals located in the urban area have a higher cost than those in the rural area. Finally, the case study of the sample hospitals offers a specific information to hospital administrators about how they share in terms of the cost they are incurring in comparison to other hospitals. For example, if his/her hospital is of small size and located in a city, he/she can compare the various costs of his/her hospital operation with those of other similar hospitals. Therefore, he/she may be able to find the reasons why the cost of his/her hospital operation has a higher or lower cost than other similar hospitals in what factors of the hospital cost determinants.

• KSBB Journal
• /
• v.23 no.3
• /
• pp.231-238
• /
• 2008

The second family member of tissue inhibitors of matrix metalloproteinases, TIMP-2, is a 21kDa protein which inhibits matrix metalloproteinases 2 (MMP-2). Expression of mammalian proteins in E. coli often forms inclusion bodies that are made up of mis-folded or insoluble protein aggregates. The requirement for the formation of 6 disulfide bonds in the process of the TIMP-2 folding is likely to be incompatible with the reducing environment of E. coli. However, this incompatibility can be often overcome by introducing a mutagenesis that could lead to enhancement of the protein solubility. In this reason, we have attempted to express the soluble TIMP-2 in E. coli by applying a modified staggered extension process (StEP), one of the in vitro PCR-based recombinant mutagenesis methods, and error-prone PCR. C-terminally located CAT fusion protein with respect to mutated TIMP-2 proteins enables us to differentiate the soluble TIMP-2 from the insoluble in E. coli by virtue of chloramphenicol resistance. According to this scheme, E. coli harboring properly-folded CAT fused to TIMP-2 protein was selected, and some of the resulting colonies exhibited an enhanced, soluble expression of TIMP-2 compared to the wild type, implying (i) the StEP technique is successfully employed to enhance the proper folding thereby increasing the solubility of TIMP-2, and (ii) the CAT dependent screening may be a simple and effective method to differentiate the soluble protein expression in E. coli.

• Journal of Korean Society of Forest Science
• /
• v.80 no.2
• /
• pp.151-161
• /
• 1991

I tried to specify the taxa of Fagaceae in Korea by the character of their pollen grains. The light microscope(LM) and the Scanning electron microscope(SEM) were used to examine the pollen grains of 19 taxa, 5 genera. The result are as follows. 1. The pollen of Fagaceae in Korea could be grouped into four types and 4 subtypes. 1) Fagus type 2) Castanea type 3) Lithocarpus, Castanopsis type 4) Quercus type (1) Cyclobalanopsis subtype (2) Prinus subtype (3) Dentatae subtype (4) Cerris subtype. 2. The morphology of the granula on the pollen of Quercus was closely related to the differantiation of the shape of the cup scales. 1) The uniformity of branching granula on the pollen grain surface corresponds to the morphological features of the concentric arrangement of cup scales. 2) The morphological features of the pollen grain surface intermingled with large or small granula, simple-granula and tuber granula which have small points of circular prominence, corresponded to those of short cup scales. 3) The morphological features of the polllen grain surface intermingled with large or small granula, simple-granula and tuber granula with an apex of amoeba type corresponded to those of Q. dentata Thunb, with thin, fine and long cup scales. 4) The morphological features of the pollen grain surface intermingled with large of small granula of with only simple-granula, corresponded to those of Q. acutissima carr. with thick, fine and long cup scales. 3. The result of cluster analysis by coding the sculpture pattern of the pollen grain surface, the existence and nonexistence of surface perforate, the grain size and granula type were coincident with the system of classification of plants and showed an intimated relationship even under th level of species.