• KDI Journal of Economic Policy
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• v.32 no.1
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• pp.131-169
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• 2010

I develop a matching model in which risk-averse workers face borrowing constraints and make a labor force participation decision as well as a job search decision. A sharp distinction between unemployment and out of the labor force is made: those who look for work for a certain period but find no job are classified as the unemployed and those who do not look for work are classified as those out of the labor force. In the model, the job search decision consists of two steps. First, each individual who is not working obtains information about employment opportunities. Second, each individual who decides to search has to take costly actions to find a job. Since individuals differ with respect to asset holdings, they have different reservation job-finding probabilities at which an individual is indifferent between searching and not searching. Individuals, who have large asset holdings and thereby are less likely to participate in the labor market, have high reservation job-finding probability, and they are less likely to search if they have less quality of information. In other words, if individuals with large asset holdings search for job, they must have very high quality of information and face very high actual job-finding probability. On the other hand, individuals with small asset holdings have low reservation job-finding probability and they are likely to search for less quality of information. They face very low actual job-finding probability and seem to remain unemployed for a long time. Therefore, differences in the quality of information explain heterogeneous job search decisions among individuals as well as higher job finding probability for those who reenter the labor market than for those who remain in the labor force. The effect of the extended maximum duration of unemployment insurance benefits on the aggregate labor market and the labor market flows is investigated. The benchmark benefit duration is set to three months. As maximum benefit duration is extended up to six months, the employment-population ratio decreases while the unemployment rate increases because individuals who are eligible for benefits have strong incentives to remain unemployed and decide to search even if they obtain less quality of information, which leads to low job-finding probability and then high unemployment rate. Then, the vacancy-unemployment ratio decreases and, in turn, the job-finding probability for both the unemployed and those out of the labor force decrease. Finally, the outflow from nonparticipation decreases with benefit duration because the equilibrium job-finding probability decreases. As the job-finding probability decreases, those who are out of the labor force are less likely to search for the same quality of information. I also consider the matching model with two states of employment and unemployment. Compared to the results of the two-state model, the simulated effects of changes in benefit duration on the aggregate labor market and the labor market flows are quite large and significant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1897-1904
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• 2010

The administration data of the national health insurance and health insurance bills were utilized in this study. The data of 432,915 patients who were at the age of 30 and up and used the out-patient departments of every medical institution located in some regions involving two southern and northern provinces once or more during a 184-day period from July to December. As a result of analyzing their prescription compliance and factors affecting it, the following findings were given: The average rate of the prescription compliance of the patients stood at 61.5 percent. It denoted that they were prescribed to take medicine for approximately 113 days during the six-month(184 days) period of time, and the rate of the patients who complied with the prescriptions just stood at 13.0 percent. They used out-patient department for 4.3 days on the average due to hypertension and they visited 1.1 medical institutions on the average. 94.9 percent just used a medical institution. The largest group (11.6%) suffered from diabetes as co-morbidity, and 23.3 percent of the hypertensives had co-morbidity. Concerning the relationship between their characteristics and prescription compliance, those who were male, who were beneficiaries of the national health insurance, who mainly used general hospitals and who suffered from co-morbidity complied better with the prescription they got. Their prescription compliance got better at the age of 65 to 74 and got worse afterwards. As for factors affecting their prescription compliance, the patients who were male, who were aged between 55 and 64 and who were beneficiaries of the national health insurance, who mainly used specialized general hospitals, general hospitals and public health centers and who had heart diseases and diabetes as co-morbidity complied better with the prescriptions. The above-mentioned findings of the study suggested that it's needed to make a factor analysis of the poor prescription compliance of patients from diverse angles, and that existing hypertension care plans should carefully be reviewed to improve the prescription compliance of patients and to find a feasible alternative. As hypertensives are easily likely to develop co-morbidity like diabetes, systematic health education should be provided for them to get into the right life habits such as taking low-salt meals or quitting smoking. In addition, the development of health care programs is required.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.315-327
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• 2007

This study investigated temporal and spatial variation of Pb and stable Pb isotopes accumulated in Ulleung Basin core sediments (4) using MC ICP/MS in order to identify the sources of anthropogenic Pb in the East/Japan Sea. Leached (1M HCl) Pb concentration and isotope ratios ($^{207}Pb/^{206}Pb\;and\;^{208}Pb/^{206}Pb$) were nearly constant during 300 yrs past than 1930, but increased up to twice in concentration and as much as 3.41% (1.70%) after 2000. On the other hand, residual Pb concentrations were nearly constant for past 400 yrs. The accumulation rates of anthropogenic Pb in the basin area were in the range of $3.1-3.5mg/m^2/yr$, which were similar levels to total atmospheric Pb deposition fluxes from 1990s to the present. In the slope area, more increase of anthropogenic Pb accumulation than the levels expected from mass accumulation rate could be found after the middle of 1990s. From the detailed evaluation for the temporal and spatial variation of accumulation rate and isotope ratios of anthropogenic Pb, we proposed probable sources and pathways of anthropogenic Pb. Pb emmision by coal burning from the China and Korea initiated the accumulation of anthropogenic Pb in the sediments of East/Japan Sea from 1930s. The accumulation of Pb increased by the addition of anti-nocking agents from both countries untill the beginning of 1990s, but from the middle of 1990s to the present, the phase-out of gasoline additives and the rapid increase of coal burning from the China maintained the atmospheric Pb levels in the Ulleung basin nearly similar to before. However, the local sources within this basin might take an important role in the rapid increase of anthropogenic Pb accumulation in slope areas from the middle of 1990s.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1051-1054
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• 1993

The International Atomic Energy Agency's Statute in Article III.A.5 allows it“to establish and administer safeguards designed to ensure that special fissionable and other materials, services, equipment, facilities and information made available by the Agency or at its request or under its supervision or control are not used in such a way as to further any military purpose; and to apply safeguards, at the request of the parties, to any bilateral or multilateral arrangement, or at the request of a State, to any of that State's activities in the field of atomic energy”. Safeguards are essentially a technical means of verifying the fulfilment of political obligations undertaken by States and given a legal force in international agreements relating to the peaceful uses of nuclear energy. The main political objectives are: to assure the international community that States are complying with their non-proliferation and other peaceful undertakings; and to deter (a) the diversion of afeguarded nuclear materials to the production of nuclear explosives or for military purposes and (b) the misuse of safeguarded facilities with the aim of producing unsafeguarded nuclear material. It is clear that no international safeguards system can physically prevent diversion. The IAEA safeguards system is basically a verification measure designed to provide assurance in those cases in which diversion has not occurred. Verification is accomplished by two basic means: material accountancy and containment and surveillance measures. Nuclear material accountancy is the fundamental IAEA safeguards mechanism, while containment and surveillance serve as important complementary measures. Material accountancy refers to a collection of measurements and other determinations which enable the State and the Agency to maintain a current picture of the location and movement of nuclear material into and out of material balance areas, i. e. areas where all material entering or leaving is measurab e. A containment measure is one that is designed by taking advantage of structural characteristics, such as containers, tanks or pipes, etc. To establish the physical integrity of an area or item by preventing the undetected movement of nuclear material or equipment. Such measures involve the application of tamper-indicating or surveillance devices. Surveillance refers to both human and instrumental observation aimed at indicating the movement of nuclear material. The verification process consists of three over-lapping elements: (a) Provision by the State of information such as - design information describing nuclear installations; - accounting reports listing nuclear material inventories, receipts and shipments; - documents amplifying and clarifying reports, as applicable; - notification of international transfers of nuclear material. (b) Collection by the IAEA of information through inspection activities such as - verification of design information - examination of records and repo ts - measurement of nuclear material - examination of containment and surveillance measures - follow-up activities in case of unusual findings. (c) Evaluation of the information provided by the State and of that collected by inspectors to determine the completeness, accuracy and validity of the information provided by the State and to resolve any anomalies and discrepancies. To design an effective verification system, one must identify possible ways and means by which nuclear material could be diverted from peaceful uses, including means to conceal such diversions. These theoretical ways and means, which have become known as diversion strategies, are used as one of the basic inputs for the development of safeguards procedures, equipment and instrumentation. For analysis of implementation strategy purposes, it is assumed that non-compliance cannot be excluded a priori and that consequently there is a low but non-zero probability that a diversion could be attempted in all safeguards ituations. An important element of diversion strategies is the identification of various possible diversion paths; the amount, type and location of nuclear material involved, the physical route and conversion of the material that may take place, rate of removal and concealment methods, as appropriate. With regard to the physical route and conversion of nuclear material the following main categories may be considered: - unreported removal of nuclear material from an installation or during transit - unreported introduction of nuclear material into an installation - unreported transfer of nuclear material from one material balance area to another - unreported production of nuclear material, e. g. enrichment of uranium or production of plutonium - undeclared uses of the material within the installation. With respect to the amount of nuclear material that might be diverted in a given time (the diversion rate), the continuum between the following two limiting cases is cons dered: - one significant quantity or more in a short time, often known as abrupt diversion; and - one significant quantity or more per year, for example, by accumulation of smaller amounts each time to add up to a significant quantity over a period of one year, often called protracted diversion. Concealment methods may include: - restriction of access of inspectors - falsification of records, reports and other material balance areas - replacement of nuclear material, e. g. use of dummy objects - falsification of measurements or of their evaluation - interference with IAEA installed equipment.As a result of diversion and its concealment or other actions, anomalies will occur. All reasonable diversion routes, scenarios/strategies and concealment methods have to be taken into account in designing safeguards implementation strategies so as to provide sufficient opportunities for the IAEA to observe such anomalies. The safeguards approach for each facility will make a different use of these procedures, equipment and instrumentation according to the various diversion strategies which could be applicable to that facility and according to the detection and inspection goals which are applied. Postulated pathways sets of scenarios comprise those elements of diversion strategies which might be carried out at a facility or across a State's fuel cycle with declared or undeclared activities. All such factors, however, contain a degree of fuzziness that need a human judgment to make the ultimate conclusion that all material is being used for peaceful purposes. Safeguards has been traditionally based on verification of declared material and facilities using material accountancy as a fundamental measure. The strength of material accountancy is based on the fact that it allows to detect any diversion independent of the diversion route taken. Material accountancy detects a diversion after it actually happened and thus is powerless to physically prevent it and can only deter by the risk of early detection any contemplation by State authorities to carry out a diversion. Recently the IAEA has been faced with new challenges. To deal with these, various measures are being reconsidered to strengthen the safeguards system such as enhanced assessment of the completeness of the State's initial declaration of nuclear material and installations under its jurisdiction enhanced monitoring and analysis of open information and analysis of open information that may indicate inconsistencies with the State's safeguards obligations. Precise information vital for such enhanced assessments and analyses is normally not available or, if available, difficult and expensive collection of information would be necessary. Above all, realistic appraisal of truth needs sound human judgment.

• Research in Community and Public Health Nursing
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• v.7 no.1
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• pp.69-79
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• 1996

To investigate the factors related with the compliance and the treatment of the patients with pulmonary tuberculosis in urban and suburb area, we followed up all the 755 registered patients(at urban Public Health Office 544, at suburb 210) as follow from January 1,1992 to December 31, 1993. We describe the general characteristics and the characteristics related with the disease of the patients according to the area as follow. 150 patients(27.5%) were at their age of 20 to 29 years in the urban area, whereas 45 patients (21.4%) were 60 to 69 years and another 45 patients(21.4%) were 70 to 79 years in the suburb area. According to the first chest X -ray examination, 54.5% of all cases were proved to be mild in the urban area. But in the suburb area, moderate cases (44.3%) were more than mild cases(p<0.01). Follow-up X-ray's were performed more properly(p<0.05) in the urban area(94.3%) than in the suburb area(90.0%). Most cases were found in the chest X -ray examination performed by Public Health Office (p<0.01) : payable chest X-ray in the urban area (56.7%) and free chest X-ray in the suburb area(35.2%). More patients were cured in the urban area(90.8%) than in the suburb area(87.1%). The presence of supporting family member were significantly higher(p<0.05) in the urban area(79.1%) than in the suburb area(88.1%). In the analysis of the treatment efficacy, more cure ate were found in the patients cytologically confirmed to be culture (+). In the urban area, 201 culture (+) patients (93.5%) 294 culture (-) patients (89.1%) were cured. In the suburb area, 99 culture (+) patients(91.7%) and 84 culture (-) patients(82.4%) were cured. Age, the presence of supporting family member, and the socioeconomic status of the patient had significant association with the prescription compliance related with the general characteristics of the patients. Whereas, X-ray finding and AFB culture finding were the significant factors associated with the prescription compliance related with pulmonary tuberculosis (p<0.05). The cumulative compliance in the survival analysis was 92.5% in the urban area and 88.1% in suburb area, at sixth month of follow-up. Failure rate for regular drug receipt was highest at second month in the urban area(3.75%) and at fourth month in the suburb area(4.15%). In logistic regression of the factors related with the tratment result, first X-ray examination and prescription compliance were significantly associated in the urban area(p<0.05). However, there is no factor significantly associated with the treatment result in the suburb area. It could be explained by too small size of the sample. In logistic regression of the factors related with the prescription compliance, first chest X-ray, sputum culture outcome and the presence of supporting family member were significant variables in the urban area(p<0.05). Most patients with family member were proved to be compliant with the prescription. This shows that it is important for the patients with long-lasting ilnesses to have supporting family member. Therefore, to improve prescription compliance we should strengthen the health education before the initiation of treatment and take special interest in the patients without supporting family member.

• Applied Biological Chemistry
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• v.15 no.1
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• pp.77-84
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• 1972

A field experiment was conducted to determine the factors responsible in limiting nutrient up take and root activity in low productive paddy fold. Radiosotope of phosphorus-32 was used as a tracer. Results of the study were as follows: 1. On yield components responsible for increase yield indicated that number of ears per panicle and ripening ratio were closely related to increase yield. 2. Root volume or root feeding area has significant influence in increasing rice yield. 3. Root volume indicative of root activity and nutrient uptake can be effected by reasonable water control. 4. The combined application of calcium, silica, and magnesium(as a fused magnesium phosphate. the Kyun-gi Chemical Co. products.) with water control, although under conditions of large amount application of nitrogen, was found to be increased the maturing rate. 5. In the plots of water control, the number of roots per one volume were less than that of the continuous flooding plots, but the weight per root was heavier than the flooding plot ones. 6. Improvement of the present native culture method could effectively increase paddy rice yield.

• Economic and Environmental Geology
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• v.12 no.1
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• pp.41-49
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• 1979

A literature review is made on the physical and chemical characteristics of clay minerals in acidic solutions from the mineralogical and hydrometallurgical viewpoints. Some of the important characteristics of clays are their ability to cation exchange, swelling, and incongruent dissolution in acidic solutions. Various clay minerals can take up metallic ions from solution via cation exchange mechanism. Generally, cation exchange capacity increases in the following order : kaolinite, halloysite, illite, vermiculite, and montmorillonite. In acidic solutions, the cation uptake such as copper by clay minerals is strongly inhibited by hydrogen and aluminum ions and thus is not economically significant factor for recovery of metals such as uranium and copper. In acidic solutions, the cation uptake is substial. Swelling is minimal at lower pH, possibly due to lattice collapse. Swelling may be controllable with montmorillonite type clays by exchanging interlayer sodium with lithium and/or hydroxylated aluminum species. The effect of add on clay minerals are : 1. Division of aggregates into smaller plates with increase in surface area and porosity. 2. Clay-acid reactions occur in the following order: (i) $H^+$ replacement of interlayer cations, (ii) removal of octahedral cations, such as Al, Fe, and Mg, and (iii) removal of tetrahedral Al ions. Acid attack initiates, around the edges of the clay particles and continued inward, leaving hydrated silica gel residue around the edges. 3. Reaction rates of (ii) and (iii) are pseudo-1st order and proportional to acid concentration. Rate doubles for every temperature increment of $10^{\circ}C$. Implications in in-situ leaching of copper or uranium with acid are : 1. Over the life span of the operation for a year or more, clays attacked by acid will leave silica gel. If such gel covers the surface of valuable mineral surfaces being leached, recovery could be substantially delayed. 2. For a copper deposit containing 0.5% each of clay minerals and recoverable copper, the added cost due to clay-acid reaction is about 1.5c/lb of copper (or 0.93 lbs of $H_2SO_4/1b$ of copper). This acid consumption by clay may be a factor for economic evaluation of in-situ leaching of an oxide copper deposit.

• Journal of Preventive Medicine and Public Health
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• v.1 no.1
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• pp.51-66
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• 1968

During a period of about one year(November '66 to December '67), the Yonsei University College of Medicine conducted a field trial of the oral contraceptive(Ovulen) in order to study its acceptability and use-effectiveness among IUD drop-outs in Koyang county. We can summarize the outstanding findings from this investigation as follows; 1. 61.4% of the IUD drop-outs interviewed (911 women) wanted to use the pill. Most of the reasons for not wanting to use it(352 women) pertained to either use of other contraceptive methods(98) or subfecundity(150) following IUD terminations. Only 83 out of 911 women gave reasons related to the difficulty of obtaining pills. Therefore, we can state that most IUD drop-outs if still in need of a contraceptive methods are in favor of trying the pill, and especially so if this method is conveniently available. 2. The 467 women or 37% of those who terminated IUD use actually visited the clinic for medical screening, and only 11 of them or 2.4% were rejected because of pregnancy and other medical reasons such as cervical erosion, myoma, breast mass, etc. 5.5% or 25 of the 456 women who received the first cycle did not take a single pill during the study period. 3. When we defined those 431 women who accepted and took one or more tablets we found that women over age 30, with 4 or more children, and/or with a higher educational level were the best prospects for recruitment. 4. In accuracy of use, about two thirds of the users started taking the pill on the 5 th day as directed for the first three cycles, but the percentages rose sharply to about 80% in later cycles. Tardiness in starting pill use in the first cycle may have occurred partly because they had to return to the clinic monthly to get each new cycle. Among acceptors who did not quit between cycles, 80 to 90% were regular users, missing two or less tablets in each cycle. 5) More than 60% of the users felt well and sometimes lost their pre-acceptance symptoms. especially dysmenorrhea. However, 27.4% (58 women) had side effects attributable to the pill compund as nausea, vomiting, indigestion, breast tenderness, decreased lactation or breakthrough bleeding. 25.0% (53 women) also complained of medical diseases or symptoms not related to the pill, especially during the first three cycles. However, as the confidence and experience of the client and the field workers grew, the incidence of unrelated medical complaints quickly fell to a lower level in the later cycles. 6. As of the end of this study, on December 31, 1967, 49.2% (212 women) had discontinued the use of the pill for medical reasons as well as for the non medical reasons. Only one case terminated use due to a pregnancy after taking pills. The cumulative continuation rates (by the life table method), were 58.9%, 51.9%, 41.0% at the end of 3 months, 6 months and one year, respectively. These rates are lower than in the U.S. studies. Even when we add the retaking group to the first segment, the continuation rate goes up only about 5% above the first segment rates mentioned above. Possible explanations are different dosages, the newerness of the method and the use of only one point for pill distribution in the country together with a monthly return for cycle 1, 2, 3, and 4-6.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.62-68
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• 1994

This study was aimed to compare the density of the functional microcirculation of hepatocellular carcinoma (HCC) with normal liver and to investigate the effect of hepatic-arterial oily chemoembolization (HAE) by radionuclide examination. Methods : Eight patients with HCC proven by biopsy in five, and clinically and radiologically in three were included. The mixture of 2 cc normal saline with three to four mCi of $^{99m}Tc$-MAA was infused through a hepatic-arterial catheter for a minute. Dynamic images were obtained at a rate of 4 sec per frame for a minute, and static images and SPECT were followed. Results : In three patients who underwent hepatic arterial angiography (HAA) alone, radioactivity was markedly increased in tumors compared to the adjacent liver immediately after infusion of $^{99m}Tc$-MAA. The ratios of tumoral and extratumoral up-take (T/E ratio) were above 6.5 (range; $6.5{\sim}l9$, mean; 12.5). In four of the five patients who under-went superselective HAE, T/E ratio were remark-ably decreased ($0.5{\sim}1.3$). The areas of embolization were better delineated in radionuclide study than in postembolization HAA. In the other one who was considered to be embolized completely on HAA, strong radiouptake in the tumor was disclosed (T/E ratio; 7.0). Conclusions : Therefore hepatic-arterial flow study with radionuclide imaging using $^{99m}Tc$-MAA can be a valuable method to assess the accurate embolization effect in HCC.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.4
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• pp.57-68
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• 1982

The paddy fiels slope located in Kangweon province Hwyongsung gun Gonggeun myon Shinchonri was considerably steep and so it was impossible to economically consolidate the field up to date. But for the porpose of farm mechanization, the field (32. 27ha) was consolidated by the auther under the assitance of the Ministry of Agriculture and Fishery and,;the Administration of Kangweon province. This paddy field consolidation was caused by the treatise on "Land-consolidation methods for farm mechanization in the steep-sloped paddy field", of which the auther is the same. The constrution was carried out from September, 1981 to April, 1982. During the 4esign and construction, some Peculiarities were found and discussed. That is, in design, besides the common condititions for a design, some special conditions were considered and written below; (1) The ranges of field slope in this design were 1/100-1/30. (2) Long sides of the land readjustment blocks must be arranged abreast contour line, and so they make the amount of cutting and banking decreased so as to take the maximum advantage of the configuration of the field. (3) In design, the main principles of dividing blocks were written below; i) First of all, long side of a block should be drawn straight abreast a contour line. ii) Long side of a block should arrange abreast contour line and make its length 100-150m, if not, l)reak the side in order to make a bended rectangle. iii) Length of a short side should be determinded within differences of elevation (0.6 -1. 2m) between the two adjacent blocks toward the normal to a contour line. iv) Length of a short side should be above 15m and the ratio of long and short side should be slso kept 1: (4-6). v) A new field surface leveling was determinded from the elevation which produce the least amount of cuttingand banking within the range of 0.6-1. 2m diffe rences of elevation between the two adjacent blocks. vi) In the course of dividing blocks with the same width along the line which was normal to a contour line, all blocks connot keep their shape in a retangle because of steep slope of the field and so on, and so it was also necessory to make some non-retanglar and small blocks such as a trianglar or trapezoidal shape, which was impossible to use some of farm machinery. But because this non-rectanglar and small blocks were divided, larger and many rectanglar blocks can be divided and construction cost can also be lowered. According to the conditions discussed above, the paddy field consolidation project designed and constructed. And the results of this study were obtained as below; (1) Three-forth of total cost of this paddy field consolidation was not construction cost, and these cost consist of land grading (1/4), road and canal construction cost (1/4) and the other cost (1/4) such as surveying or materials and 56 on. (2) The steeper the land slope, the greater cost was assigned for road and canal construction, and than land grading. (3) Curtailment of the road and canal construction cost depended on simplificating their strutures. (4) In the case of the land slopes were low, the land grading cost was high by 1: 1.4 in comparison with the road and canal construction cost, and conversely when the slops were steep, the road and canal construction cost was high by 1 : 5 in compa- rison with the land grading cost. (5) The densities of irrigation canal, drainage canal and trunk and branch road were 150. Sm/ha, 60. im/ha and 17. 4m/ha respectively. The density of irrigation canal of the area was high by 2 times in comparison with the average one of Kangweon Province, and the others were nearly the same. (6) Most farmers (above 85%) knew the effects of paddy field consolidation. The effects are; 1) Improvement of irrigation 2) Improvement of farm management 3) Improvement of transportarion 4) farm mechanization and 5) grouping of the scattered land. And the more farm modernization was accomplished by these projects, the more farmers wanted to live in their land. (7) In spite of the very steep sloped paddy field, the diminution rate of the net farm land caused by consolidation was 7.7% which was nearly the same as the one of Chulweon plain of Kangweon province. Land grading cost was 971, OOOwon/ha which was rather cheap by 13.2% than the one of Ghulweon plain, and unit construction cost was 5, 341, OOOwon/ha (included soil addition) which was also nearly the same as the one of Chulweon plain and FNFIA (The federation of national farmland improvement association).