• Korean journal of applied entomology
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• v.32 no.3
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• pp.338-347
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• 1993

The study was to investigate the bionomics, host plants, and oviposition preference of Hishimonus sellatus Uhler. It has 5 generations under natural conditions and the peak of the 3rd generation was observed about mid and late August. Its average developmental durations were 80 days in spring, 69 days in summer, and 77.8 days in autumn. The lengths of each stage were 0.8mm in eggs, 0.9mm in 1st instar, 1.4mm in 2nd instar, 2.1mm in 3rd instar, 2.5mm in 4th instar, 3.2mm in 5th instar, 4.1mm in female, and 3.8mm in male. Hishimonus sellatus overwintered as egg in Morus alba, Humulus japonicus, and Zizyphus jujuba begining mid October, and attacked the shoot of M. alba and H. japonicus about mid and late May, migrated to the Zizyphus jujuba from late June to early July. Female oviposites 32~62 eggs into epidermis of shoot, vagina and vein during their life. The preferred host plants of H. sellatus were Humulus japonicus, Morus alba, Zizyphus jujuba, and ligustrum obtusifolium. Highly preferable oviposition site was H. japonicus, M. albal, Z. jujuba, and L. obtusifolium, etc. On audlt longevity, the host plants as H. japonicus, M. alba, and Z. jujuba were 43$\pm$2 days and A. brevipedenculata, C. mimosoides, L. obtusifolium, V. rosa, A. sinicus and, A. graveolens were more than 25 days, and other host plants were less than 20 days.

• 한국벤처창업학회:학술대회논문집
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• 2017.08a
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• pp.15-35
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• 2017

The purpose of this research is to investigate the factors which effect the intention to reemploy after the retirement and the mediation effect of the social capitalism for retired and prospective retired baby boomers. Starting from 2010, baby boomers have been retiring at a large scale. However retirement at a large scale without securing provision for fiancial wise in later life can lead to many issues regarding social and fiancial wise such as instability of labour market and increase of spending in society welfare cost and such on. Change of individual's self prospective and institutional support to help prepare find new career for next 3decade after the retirement needs to be concretized. Also, while in the work force, potential retiring baby boomer workers should be systematically supported with education, training and reemployment program based on individual's career orientation and allowing them to stay for a longer period in the labour market can be the implication to the solution for the economic stability and increasing social cost such as public pensions.

• Korean journal of applied entomology
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• v.40 no.1
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• pp.45-45
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• 2001

Development and predation of an aphidophagous gall midge, Aphidoletes aphydimyza (Rondani) , on the green peach aphid, Myzus persicae Sulzer, were studied under laboratory and greenhouse conditions. The developmental threshold temperature of the gall midge larvae was estimated to be $13^{\circ}C$. Larval and total developmental periods were 5.3 and 29 days at 25 $\pm$$2^{\circ}C$. The gall midge attacked more aphids as increasing density of peach aphids, and consumed 4 out of 10 peach aphids per day in a petri dish (9 cm in diameter) at maximum. In green house, the gall midge could control the density of the green peach aphids efficiently with a delayed density dependent-like pattern.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.55-62
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• 2012

This paper analyze the DEA(Data Envelopment Analysis) efficiency of government budget to HRD program(ITRC) and correlation and regression between its inputs and outputs in the field of information technology. First, empirical results show that the relationship between the supporting period of government budget and scientific research & HRD outputs is respectively irrelevant. Second, another finding is that the relationship between government budget and HRD output is positive. Finally, DEA efficiency analysis implicates that SW/digital contents, digital TV, information security, intelligence robot, next generation PC, next generation mobile telecommunication, home network, mathematics, IT SoC are more efficient than any other technology fields.

• Korean journal of applied entomology
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• v.25 no.1 s.66
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• pp.37-40
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• 1986

We surveyed the IRRI farm to determine the extent of parasitization of yellow stemborer egg masses. The egg masses were randomly collected at weekly intervals from July to October 1984 from rice fields, 15-20 days after transplanting, and brought to the laboratory for collection of emerging parasites. Three species of hymenopterous parasitoids-Tetrasticus schoenobii, Telenomus rowani, and Trichogramma japonicum-were found from 700 egg masses. We introduced a method to calculate percent parasitism as based on parasite biology and behaviour. Among the three species, the combination of T. rowani and T. japonicum was the highest multiparasitization of yellow stem borer egg masses, and T. rowani, a solitary parasite had the highest number based on immature and adult stages counted. However, T. schoenobii may be the most efficient parasite because two to four host eggs are needed to complete the larval period, and it took $10{\sim}14$ days for one generation.

• Land and Housing Review
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• v.14 no.2
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• pp.73-82
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• 2023

This study empirically analyzes the policy demand for population inflow in Hongcheon-gun, a region that has experienced population decline over the past decade. The results of this study based on the multinominal logit model provide the policy implications as follows. First, due to the differing factors influencing the demand for population inflow policies among the young and the elderly, local governments should clearly define the policy targets for population inflow. Second, in the context of policy demand for population inflow through corporate attraction, we identify statistically significant and positive effects of the length of residence for both young and old people, and the level of formal education for the elderly. These results emphasize the importance of formulating population inflow policies distinctively targeted for the young and the elderly generations, respectively, thereby increasing population inflow in the population reduction area.

• Korean journal of applied entomology
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• v.41 no.2
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• pp.123-128
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• 2002

This study was carried out to test the effects of temperatures between 2$0^{\circ}C$ and 3$0^{\circ}C$ on the reproduction and development of the rice water weevil, Lissorhoptrus oryzophilus. Preoviposition periods were much longer (17.2 to 51.0 days) in the overwintering adult females collected in March than those collected in May, regardless of temperature. Oviposition periods, however, were longer (16.9 to 22.0 days) in the adult females collected in May than those collected in March at the same temperatures. The longer oviposition period observed in the females collected in May were directly associated with higher fecundity. Egg periods were shortened from as temperature increased, but the hatching rate was highest (100%) at 27$^{\circ}C$. The developmental periods from egg to adult were shortened as temperature increased : from 77.9 days at 2$0^{\circ}C$ to 38.3 days at 3$0^{\circ}C$. The developmental zero point temperature (T) and the total effect temperature (K) for egg were 16.3$^{\circ}C$ and 62.1 dgree days, respectively. The T and K from egg to adult emergence were 13.9$^{\circ}C$ and 577.6 dgree days, respectively. The adult females of the first generation did not oviposit at 2$0^{\circ}C$, but did at $25^{\circ}C$ and 3$0^{\circ}C$. The intrinsic rate of natural increase (r$_{m}$) increased as temperature augmented. Net reproductive rate (Ro) per generation was highest (75.3) at $25^{\circ}C$.>.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.6B
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• pp.1165-1173
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• 1999

In order to support various multimedia communication services, a well balanced backbone network should be designed using recently advanced optical communication technologies. In this paper an optimal backbone network configuration design is presented fur Korean traffic environment. A new traffic model, Population-Distance-Gross Group Products(PDG) traffic model, is devised. In Korean network traffic environment, six regional centers are selected, link capacities between the regional centers are estimated from the PDG traffic model, and the overall network configuration is designed for the all-optical backbone network in Korea. A simulation study is carried out to verify the desired performance of the designed backbone network. Simulation results show that performance of the backbone network is well balanced to support various communication services in Korea in the 2000s.

• Pediatric Infection and Vaccine
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• v.11 no.1
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• pp.81-89
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• 2004

Purpose : Retropharyngeal and parapharyngeal abscesses are often distinguishable from other head and neck abscesses on clinical grounds, but these infections can combine and the presentations are similar to one another. Because of the advances of antibiotic therapy, the frequency of the diseases decreased considerably, but recently the incidence of neck abscesses has increased. We sought to describe the clinical presentation of patients with deep neck abscess, and implications on management. Methods : For 10 year periods, 94 cases of charts were reviewed retrospectively, who were diagnosed as neck abscesses aged below 16 years old(between January 1993 to August 2003) in 4 hospitals. Deep neck abscesses were diagnosed by surgical pus drainage, neck CT (homogenous, hypodense area with ring enhancement) and neck sono findings. Results : The annual incidence of deep neck abscess has been increased since 2000. The median age of the patients was 4 years(range, 26 days~15 years); 63% of the patients were younger than 5 years. Abscesses in the submandibular space(34%) were most common, followed by peritonsillar space(29.7%), retropharyngeal space(11.7%), combined(10.8%), parotid space(7.4%) and parapharyngeal space(6.4%). Fever(73.4%), sore throat(37.2%), decreased oral intake(34%) and neck pain(27.7%) were the most common symptoms. In 6 children(6.4%), there was refusal to move neck, in 6(6.4%) headache, and in 4(4.3%) torticollis. Respiratory distress was observed in only 1 patient(2.1%) and stridor in 1 other(2.1%). The most common physical examinations were neck swelling/mass(67%), pharyngitis(46.8%), tonsillitis(36.2 %), and cervical lymphadenopathy(28.7%). Neck stiffness was observed in 4 patients(4.3%). Total 35 organisms were isolated in 33 patients. The most common organisms cultured by patients' blood or pus were S. aureus(34%) and S. pyogenes(28.6%). Most organisms were gram positive, and had sensitivities in vancomycin(96.4%), cefotaxime(88.9%), cephalothin (86.4%), trimethoprime-sulfamethoxazole(83.3%), and clindamycin(77.8%). 77 patients(81.9%) underwent surgery plus antibiotics; 17 patients(18.1%) were treated with antibiotics only. There is no significant differences between two groups. In duration of admission, fever after admission, and antibiotic treatment. Conclusion : The incidence of deep neck abscess has increased recently and the major symptoms have been changed. The incidence of respiratory distress or stridor is decreasing, while the incidence of abnormal head and neck symptoms and signs like headache, neck stiffness, refusal to move neck, or torticollis are increasing. Gram positive organisms are predominant, S. aureus is the most common followed by S. pyogenes. 1st generation cephalosporin has high sensitivity on gram positive organisms. Treatment with surgery plus antibiotics dose not significantly decrease total duration of antibiotic treatment or admission compared to treatment with antibiotics alone.

• Korea journal of population studies
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• v.25 no.2
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• pp.5-40
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• 2002

Using detailed data of women's work history, this study analyses the transition process between employment and non-employment over the life history in order to identity individual and structural determinants in the processes. Korean women comprise very heterogeneous groups in terms of work continuity: one group having a continuous work history and another having an interrupted work experience. While 4.0% of total women have stayed in the labor market since leaving school, 17.3% have not worked outside at all and remaining 87.9% have experienced into and out of the labor market at least once. On the average, the cumulated time of employment per woman is 8.2 years and the cumulated time of unemployment is 13.1 years. Thus Korean women work a total of only 38.5% of their whole lifetime after leaving school. We can conclude that the increase of the employment rate of married women in Korea since the 1970s has been due to the increase of the new entrants with short or little working careers into the labor market, not to the increase of women's work continuity on the whole. A women's educational achievement does not seem to be positively related to employment duration, contrary to the suggestion of the human capital theory, Rather, family variables, especially the existence of the child under 6 yens old, is a more significant determining factor for an individual's exit from employment. And there is little difference among different age cohorts which implies little improvement in the employment continuity of younger women. This study also documents the importance of structural variables, such as the type of occupation, as significant determining factors for the hazard rate. Specially women with professional jobs tend to stay longer in the labor market. Therefore, women's entry into more professional occupations is expected to contribute to the continuity of employment. Our results also show that duration-dependence is not spurious. When unobserved heterogeneity is controlled, the negative relation between the rate from employment and the duration of employment does not disappear.