• Journal of Forest and Environmental Science
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• v.17 no.1
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• pp.1-17
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• 2001

Forming a part of "Cooperative Practical Study for the Modernization of the Management of National Forest", this study was conducted to provide overall ecological information for the natural regeneration of major tree species on the basis of community structural attributes in the deciduous forest ecosystem. Followings are summarized characteristics of the natural regeneration for the selected tree species. Betula costata : Although large number of seeds are dispersed by wind, they require mineral soils to germinate. Thick litter layer could be an obstacle to germinate. After germination, the seedling requires large amount of light for successful establishment. Acer mono : Characterized by high shade tolerance and weak drought resistance, the seedling should be overcasted with more than 50% of canopy coverage. High stand density should be maintained to produce good quality of timber. The potential of coppice may be high. Ulmus laciniata : Since this species needs high rate of troll moisture and light, around 60% of canopy coverage should be maintained to retain moisture and incoming light. The competition with other vegetation should be removed for the favor of successful seedling establishment. Fraxinus mandshurica : This species requires moist mineral soils to germinate. After germination, the seedling needs large amount of light and moisture for successful establishment. Site preparation should be applied to reduce competition with weedy vegetation. Fraxinus rhynchophylla : Interval of large seed crops may be highly varied. Thick litter layer could be an obstacle to germinate. Site preparation should be applied to reduce competition with weedy vegetation so as to achieve successful seedling establishment. Quercus mongolica : Including the difficulty of seed supply by the consumption, thick litter layer and mountain bamboo cover could be the obstacle to germinate. More than 50% of relative light intensity is necessary to achieve successful seedling establishment. Kalopanax pictus : Thick litter layer could be an obstacle to germinate. The seedling needs large amount of light and moisture for successful establishment. Abies holophylla : In spite of high shade tolerance, the growth rate in sapling stage may be extremely slow. Cornus controversa : Seeds (drups) are consumed and dispersed by animals, tending to be not sufficient in seed supply. This species requires large amount of light for successful germination and seedling establishment. Tilia amurensis : The difficulty of seed supply might be expected with low seed purity and double dormancy. Since thick litter layer could be an obstacle to germinate, the species requires moist mineral soils for successful germination. The potential of coppice may be extremely high.

• Asia pacific journal of information systems
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• v.18 no.2
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• pp.1-14
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• 2008

According to technology acceptance model(TAN) which is one of the most important research models for explaining IT users' behavior, on intention of using IT is determined by usefulness and ease of use of it. However, TAM wouldn't explain the performance of using IT while it has been considered as a very good model for prediction of the intention. Many people would not be confirmed in the performance of using IT until they can control it at their will, although they think it useful and easy to use. In other words, in addition to usefulness and ease of use as in TAM, controllability is also should be a factor to determine acceptance of IT. Especially, there is a very close relationship between controllability and ease of use, both of which explain the other sides of control over the performance of using IT, so called perceived behavioral control(PBC) in social psychology. The objective of this study is to identify the relationship between ease of use and controllability, and analyse the effects of both two beliefs over performance and intention in using IT. For this purpose, we review the issues related with PBC in information systems studies as well as social psychology, Based on a review of PBC, we suggest a research model which includes the relationship between control and performance in using IT, and prove its validity empirically. Since it was introduced as qa variable for explaining volitional control for actions in theory of planned behavior(TPB), there have been confusion about concept of PBC in spite of its important role in predicting so many kinds of actions. Some studies define PBC as self-efficacy that means actor's perception of difficulty or ease of actions, while others as controllability. However, this confusion dose not imply conceptual contradiction but a double-faced feature of PBC since the performance of actions is related with both self-efficacy and controllability. In other words, these two concepts are discriminated and correlated with each other. Therefore, PBC should be considered as a composite concept consisting of self-efficacy and controllability, Use of IT has been also one of important areas for predictions by PBC. Most of them have been studied by analysis of comparison in prediction power between TAM and TPB or modification of TAM by inclusion of PBC as another belief as like usefulness and ease of use. Interestingly, unlike the other applications in social psychology, it is hard to find such confusion in the concept of PBC in the studies for use of IT. In most of studies, controllability is adapted as PBC since the concept of self-efficacy is included in ease of use explicitly. Based on these discussions, we can suggest perceived use control(PUC) which is defined as perception of control over the performance of using IT and composed of controllability and ease of use as sub-concepts. We suggest a research model explaining acceptance of IT which includes the relationships of PUC with attitude and performance of using IT. For empirical test of our research model, two user groups are selected for surveying questionnaires. In the first group, there are freshmen who take a basic course for Microsoft Excel, and the second group consists of senior students who take a course for analysis of management information by Excel. Most of measurements are adapted ones that have been validated in the other studies, while performance is real score of mid-term in each class. In result, four hypotheses related with PUC are supported statistically with very low significance level. Main contribution of this study is suggestion of PUC through theoretical review of PBC. Specifically, a hierarchical model of PUC are derived from very rigorous studies in the relationship between self-efficacy and controllability with a view of PBC in social psychology. The relationship between PUC and performance is another main contribution.

• Korea journal of population studies
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• v.12 no.2
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• pp.1-21
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• 1989

For the analysis of mortality differentials by socioeconomic factors based on death registration data, we have considered four variables : place of residence, educational attainment, marital status and occupation. The age range adopted were 5 to 64 years of age for place of residence, and 25 to 64 years of age for the other factors. The mortality differentials by socioeconomic variables were clear and in the expected direction: mortality levels among urban residents, better educated groups, and non- agricultural workers were lower than among the other sub- groups. The average mortality level in rural areas is much higher than in urban areas : the rural mortality levels were at least double the urban levels at ages below 40 years, but became smaller after age 40, and no clear differentials by urban I rural residence increased until 1974~76 for the both sexes, but since the then differentials have declined slowley for both sexes. This changing pattern of mortality differentials by place of residence can be explained by historical socioeconomic development : the development generally started in urban areas, and rural areas followed : in the course of socioeconomic development the differences between the death rates in the two areas became smaller and finally the mortality levels in the two areas became nearly the same, as is found in the developed countries nowadays. The inverse relationships between mortality and educational level became stronger between the periods 1970~72 and 1984~86, but showed the same atterns of mortality differentials in both period : larger differences among the younger age groups, and for males, than among the older age groups, and for females. The increasing mortality differentials in the fourteen-year period between 1970~72 and 1984~86 were caused by inadequate living standards of the non- educated, whose proportion in the total population, however, dropped sharply during that period. Also, the much lower proportions of low - educated groups or of persons with no formal education among males than females helped to establish the clearly pronounced differentials. The mortality differentials by marital status in Korea showed the usual pattern : the mortality rates of the married in each age and sex group were clearly lower than those of others during the fourteen-year period between 1970~72 and 1984~86. In Korean society which remotes universal marriage, the never married recorded especially high death rates, presumably mainly because of ill - health, but also possibly because of the stigma attached to celibacy. However, the mortality differentials by marital status changed with the changes in the proportionate distribution by marital status during the period : the differences between the death rates of the married and never married groups became smaller, the proportion of the never married group increased : in contrast, the differences between mortalities of the married and widowed / divorced / separated groups widened, with the decrease in the proportion of the later group ; this tendency was perticularly marked for females. Occupational groups also showed clear mortality differences : among four occupational groups mortality of males was highest among agricultural workers and lowest among 'professional, admi-nistrative and clerical workers, However, when the death rates were standardized by educational level, the death rates by occupation in age group 45~64 years were nearly the same (excet for the mixed group consisting of unemployed, students, military servicemen and unknown). Therefore, the clear mortality dfferentials by occupation in Korea resulted mainly from the differences in educational level between different occupation groups. Since socioeconomic characteristics are related to each other, the net effect of each variable was examined. Each of the three variables - ducational level, marital status and urban / rural residence affected significantly Korean adult mortality when the effects of the other variables were controlled. Among the three variables educational level was the most important factor for the determination of the adult mortality level. When male's occupation was added to the above three variables, the effects of occupation on adult mortality were notably smaller after control for the effects of the other three variables while the net effects of these three variables were nearly the same irrespectively whether occupation was included or not. Thus, the differences in educational level (mainly), place of residence and marital status bring out the clear differences in observed mortality levels by occupation.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.539-554
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• 2002

To identify the trend of pediatric dentistry in USA and Japan, closely related to Korean pediatric dentistry. The Japanese Journal of Pediatric Dentistry(JJPD) and The Journal of the American Academy of Pediatric Dentistry(PD) were reviewed. We collected the bibliographical data of the articles published in the two journals from 1991 to 2000. We analyzed thematic distributions and chronological changes, and then compare those of two groups. The following results were obtained: 1. The 869 articles were published in JJPD and 672 in PD. This was about 30% more in JJPD. 2. In both JJPD and PD, the case reports were a quarter of scientific articles in quantity. 3. The studies on the systemic diseases had the highest proportion in both JJPD and PD. The studies on the dental caries and restorative materials also had high proportion in both journals. 4. The studies on the sedation and biochemical survey had high proportion in PD when had low proportion in JJPD. To the contrary, The studies on the behavior science in JJPD were about double of those in PD. 5. There was no statistically significant difference in quantity between JJPD and PD in the studies on the dental caries, prevention of dental caries, community dental survey, conservative treatment, restorative materials, pulp treatment, diagnosis and treatment of malocclusion, oral pathology and minor surgery, local anesthesia and nerve tissue, traumatic injuries. 6. There was statistically significant increase in the studies on the dental equipment in JJPD and in those on restorative materials in PD. 7. There was statistically significant decrease in the studies on the prevention of dental caries and local anesthesia and nerve tissue in JJPD, and those on conservative treatment in PD.

• Journal of Intelligence and Information Systems
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• v.17 no.2
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• pp.97-107
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• 2011

Nowadays there are a lot of issues about copyright infringement in the Internet world because the digital content on the network can be copied and delivered easily. Indeed the copied version has same quality with the original one. So, copyright owners and content provider want a powerful solution to protect their content. The popular one of the solutions was DRM (digital rights management) that is based on encryption technology and rights control. However, DRM-free service was launched after Steve Jobs who is CEO of Apple proposed a new music service paradigm without DRM, and the DRM is disappeared at the online music market. Even though the online music service decided to not equip the DRM solution, copyright owners and content providers are still searching a solution to protect their content. A solution to replace the DRM technology is digital audio watermarking technology which can embed copyright information into the music. In this paper, the author proposed a new audio watermarking algorithm with two approaches. First, the watermark information is generated by two dimensional barcode which has error correction code. So, the information can be recovered by itself if the errors fall into the range of the error tolerance. The other one is to use chirp sequence of CDMA (code division multiple access). These make the algorithm robust to the several malicious attacks. There are many 2D barcodes. Especially, QR code which is one of the matrix barcodes can express the information and the expression is freer than that of the other matrix barcodes. QR code has the square patterns with double at the three corners and these indicate the boundary of the symbol. This feature of the QR code is proper to express the watermark information. That is, because the QR code is 2D barcodes, nonlinear code and matrix code, it can be modulated to the spread spectrum and can be used for the watermarking algorithm. The proposed algorithm assigns the different spread spectrum sequences to the individual users respectively. In the case that the assigned code sequences are orthogonal, we can identify the watermark information of the individual user from an audio content. The algorithm used the Walsh code as an orthogonal code. The watermark information is rearranged to the 1D sequence from 2D barcode and modulated by the Walsh code. The modulated watermark information is embedded into the DCT (discrete cosine transform) domain of the original audio content. For the performance evaluation, I used 3 audio samples, "Amazing Grace", "Oh! Carol" and "Take me home country roads", The attacks for the robustness test were MP3 compression, echo attack, and sub woofer boost. The MP3 compression was performed by a tool of Cool Edit Pro 2.0. The specification of MP3 was CBR(Constant Bit Rate) 128kbps, 44,100Hz, and stereo. The echo attack had the echo with initial volume 70%, decay 75%, and delay 100msec. The sub woofer boost attack was a modification attack of low frequency part in the Fourier coefficients. The test results showed the proposed algorithm is robust to the attacks. In the MP3 attack, the strength of the watermark information is not affected, and then the watermark can be detected from all of the sample audios. In the sub woofer boost attack, the watermark was detected when the strength is 0.3. Also, in the case of echo attack, the watermark can be identified if the strength is greater and equal than 0.5.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.6
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• pp.309-315
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• 2006

Purpose: Accurate evaluation of cervical lymph node (LN) metastasis of head and neck squamous cell canter (SCC) is important to treatment planning. We evaluated the diagnostic accuracy of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for the detection of cervical LN metastasis of head and neck SCC and performed a retrospective comparison with CT/MRI findings. Materials & Methods: Seventeen patients with pathologically proven head and neck SCC underwent F-18 FDG PET/CT and CT/MRI within 4 week before surgery. We recorded lymph node metastases according to the neck level system of imaging-based nodal classification. F-18 FDG PET/CT images were analyzed visually for assessment of regional tracer uptake in LN. We analyzed the differences in sensitivity and specificity between F-18 FDG PET/CT and CT/MRI using the Chi-square test. Results: Among the 17 patients, a total of 123 LN levels were dissected, 29 of which showed metastatic involvement. The sensitivity and specificity of F-18 FDG PET/CT for detecting cervical LN metastasis on a level-by-level basis were 69% (20/29) and 99% (93/94). The sensitivity and specificity of CT/MRI were 62% (18/29) and 96% (90/94). There was no significant difference in diagnostic accuracy between F-18 FDG PET/CT and CT/MRI. Interestingly, F-18 FDG PET/CT detected double primary tumor (hepatocellular carcinoma) and rib metastasis, respectively. Conclusion: There was not statistically significant difference of diagnostic accuracy between F-18 FDG PET/CT and CT/MRI for the detection of cervical LN metastasis of head and neck SCC. The low sensitivity of F-18 FDG PET/CT was due to limited resolution for small metastatic deposits.

• Clinical and Experimental Pediatrics
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• v.48 no.2
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• pp.186-190
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• 2005

Purpose : The purpose of this study was to evaluate the responses and toxicities of risk-adapted chemotherapy in pediatric intracranial germ cell tumors(IC-GCT). Methods : Fourteen patients who were diagnosed as IC-GCT from October 2002 to December 2003 received chemotherapy as an initial treatment modality. The low risk(LR) group was defined as follows : Pure germinoma and normal AFP level. Beta-hCG level 50 mIU/mL or less. The others belonged to the high risk(HR) group. Chemotherapy was composed of cisplatin, cyclophosphamide, etoposide and vincristine. Double doses of cisplatin and cyclophosphamide was used in HR patients. Results : Pathologic confirmation was done in all but one. Median age at diagnosis was 11.6 yr (1.2-18.7 yr), and nine patients belonged to the HR group. Tumor markers were normalized after chemotherapy in all patients whose tumor markers had been elevated. Four LR patients(80 percent) and seven HR patients(77.8 percent) showed complete response(CR) at the end of chemotherapy. An additional two of the three patients with partial response(PR) achieved CR after radiation therapy (RT), and the remaining one relapsed before RT. Four LR and all HR patients experienced infectious episodes that required hospitalization. Four of the nine HR patients(44.4 percent) suffered from tinnitus, three of whom developed sensorineural hearing loss. All but one are surviving, event-free, with a median follow-up of 13.9 mo(8.1-22.3 mo). Conclusion : Risk-adapted cisplatin-based chemotherapy was effective even in HR patients, but regimen modification seems to be necessary to avoid an unacceptably high toxicity rate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.4
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• pp.283-289
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• 2016

This study was carried out to identify the optimum seeding dates for selecting a double-cropping system and to assess the effect of polyethylene film mulching on the yield of Proso millet. Seeds of the varieties Hwanggeumgijang and Ibaegchal were sown in Miryang on five different dates: 1st (May 25), 2nd (June 15), 3rd (June 25), 4th (July 5), and 5th (July 15), with and without polyvinyl mulching. The varieties have different characteristics, for example, Hwanggeumgijang is an early-maturing type and more sensitive to temperature, whereas Ibaegchal is a medium-maturing type and more sensitive to the duration for which it is exposed to sunlight. Late-sown Hwanggeumgijang had a short heading date from seeding and required a low accumulated temperature. It also had a shorter period of heading, a shorter culm length and a shorter diameter of stem. In contrast, it had had a higher number of ears $per\;m^2$ although similar ear length and similar 1000-grain weight. The yield potential of Hwanggeumgijang was found to decrease at a late seeding date. In particular, it significantly decreased at the seeding date of July 15. In the case of cultivation with polyvinyl mulching, the period of heading was shorter by 2-4 days and the yield potential was increased by approximately 12-32%. The length and diameter of culm in Ibaegchal were slowly decreased, but the length of ear, the 1000-grain weight and the yield potential were similar for all seeding dates (except July 15) and cultivation with and without mulching. When sown late, the length and diameter of the culm of Ibaegchal very rapidly decreased by the July 15 seeding date. The protein content of Ibaegchal was higher but the amlyose content of Ibaechal was lower compared to Hwanggeumgijang. At late seeding dates, the protein contents of the two varieties increased but the amylose contents were similar.

• The Korean Society of Law and Medicine
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• v.17 no.2
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• pp.281-313
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• 2016

Our Constitution obliges the state to protect the health of the people, and the Medical Law, which embodied Constitution, sets out in detail the matters related to open the medical institution and one of them is to prohibit the operation of multiple medical institutions In the past, there was a provision stipulating the same purpose. But because the Supreme Court interpreted that several medical institutions could be opened if the medical treatment was not made at the additional medical instition which was opened in the another doctor,s license, multiple medical institutions could be opened and operated. However, some health care providers opened the several medical institutions to another doctor's license just by the excuse of the business management and then did illegal medical cares like the unfair luring of patients, overtreatment, and commition treatment for more profits. So, the health rights of the people came to be infringed on. Accordingly, lawmakers amended the Medical Law for medical personnel not to open and to operate more than one medical institution. As the amended medical law prohibited a medical personnel to open multiple medical institution, some medical personnels insisted that the amended medical law is unconstitutional under which they could not be able to open and operate medical institutions on based on free investment and bring out the benefits of network hospitals. But the regulation to prohibit multiple institutions does not apply only to a medical personnel. Many other experts like lawyer and pharmacist can open only one office under such a restriction. If the regulation goes out of force, the procedure that multiple medical institutions should be opened and operated in the capacity as a medical corporation or a non-profit corporation does not have to be followed. And we should keep in mind that the permission for medical personels to open multiple medical institutions could lead virtually to commercial hospital. If in the nation with a very low rate of public medical service, If only a few medical personnels with capital own many medical institutions and operate commercially them, this could cause a falling-off in quality of medical service, ultimately infringe on the health rights and the life right of the people.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1062-1068
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• 1997

From August 1989 to January 1996, a total of 105 cases of bidirectional Glean operations have been done as the interim stage for the patien s with some risk of univentricular correction at Sejong General Hospital. From December 1992, we started the conversion to Fontal operations for them, and 42 cases underwent Fontal-stage operation till February 1996. Their diagnoses were univentricular heart in 19(right ventricular type : 14), tricuspid atresia 11, double outlet of right ventricle 9, and others in 3 cases. The median age of bidirectional Glerln-stage operation was 12.5 months(range 2 months to 8 years) and Fontan-stage operation was at 59.6 months of median age(range 1 year 5 months to ,9 year 7 months). The mean waiting interval between the two operations was 33.88 $\pm$ 17.85 months with a range of 10 months to 6 years 3 months. During the waiting periods, 18 patients developed significant systemic-pulmonary collaterals andfor systemic verso-veno collateral channels. There were 5 hospital deaths after operations due to low cardiac output in 4 and sepsis in one. Most of the Fontal-stage operations were done by the late al tunneling with Core-Tex tube graft patch and fenestrated with the size of 2.5 ~6 mm. All the patients were followed-up(7 months to 4 years 2 months, mean 21.97$\pm$10.82 months) and there were 5 late deaths(postoperatively 6 months to 2 years) due to thromboembolism in 1, after heart transplantation 1, plastic bronchitis 1, protein loosing enteropathy 1, and pneumonia in 1. Dividing the patients by the waiting interval of 2 years, the early correction to Fontal group (N=16) showed the better results(hospital mortality 1116, late mortality 1116, significant collateral development 2/16) compared to the other group(N=26) (4/26, 4/26, 16/26). In conclusion, after the bidirectional Glean-stage operation successfully got rid of the previous risk factors, we recommand to do the Fontan-stage operation no later than 2 years of interval.