• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.317-331
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• 1989

Chaenogobius laevis inhabit brackish waters. Adult male protects egg mass laid under the stones. The egg with small oil globule varied from 3.40 to 4.04 mm in diameter. When water temperature is $22.0\~23.0^{\circ}C$, larvae hatched about 113 hours after fertilization. The newly hatched larvae reared for 33 days grow up to 12.10 mm in total length and developed to the jevenile. When larvae length attained about 8.0 mm, jaw bones were more rapidly ossified than vertebrae and cranium.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.342-350
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• 1989

Maturity and spawning of Crangon affinis were studied based on the histological observation. The samples were monthly collected in Nakdong estuary from June, 1988 to May, 1989. The gonad lies on the dorsal side of the thorax. The cavity in which it lies is located below heart and above hepatopancreas. Anterior part of ovary is fused roundly, and the posterior part shows a pair of tubule-like structure. Testis is bilaterally symmetrical; the anterior part shows convoluted tubule, and the posterior part consists of a pair of tubule. Seminal vesicle is connected and opened to the base of the fifth pereiopod. Gametogenesis of ovum and spermatozoon is being repeated in short period without seasonality, and it is formed simultaneously in the whole parts of germinal epithelium. Diameter of a ripe oocyte is ca. $430{\mu}m$. Spermatozoa is oval with distinct nucleoplasm. Reproductive cycle is performed in ca. 40 days. Crangon affinis spawns all year round except November. Incubation period of brooded eggs took $12\~14$ days before hatching in the aquarium at $21^{\circ}C\~24^{\circ}C\;and\;33\%_{\circ}$.

• Korean Journal of Environmental Biology
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• v.18 no.3
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• pp.323-330
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• 2000

Early life history and spawning for Odontobutis interrupta were observed in the laboratory during May-August 1999 with a condition of natural habitats in the field. Optimal water temperature for spawning was between 17.5 and 22.$0^{\circ}C$ and appropriate water depth and current velocity in the natural habitat ranged 0.3-0.6 m and 0.1-0.3 m/sec, respectively. Ovary maturation index peaked at about 100mm in the total length and their values gradually decreased after the size. Male fishes showed a territory and courtship behavior to adult females and the males frequently pushed upper-ventral part of females for egg releases. After females spawned, the males guarded the egg masses and supplied dissolved oxygen using pectoral fins. According to observation of egg development in the laboratory, blastodisc formed in 1hr 17 min after the fertilization, cleavaging at 36-minute interval regularly. Blastulation occurred in 7 hr 12 min after the fertilization, with gastrulation after 11 hr 11 mins and formation of york plug after 32 hr 48 min. Embryo was formed in 33 hr 45 min after fertilization and optic vesicles appeared in 47 hr 27 mins when 30-31 somites were formed. Cardiac primordium was formed in 65 hr 15mins and its beat averaged 44- 48 time/min. Pectoral fins were formed in 138 hr 40 min, air-bladder and black vesicles were observed in lower portion of young fish. Embryo hatched from she-11 membrane after about 10 days and juvenile was 5.8$\pm$0.2mm in total length 3.0$\pm$0.5mg in weight.

• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.82-90
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• 1999

The buddhistic painting of Song-Kwang temple in Seungjoo-gun, Chonnam, Korea is not known in chronicle, but it could be estimated to works in the early 19th century through it's remaining records and qualities of materials. And it was analysed the qualities of materials consisting of pigment layer, silken-ground layer and support layer in order to preserve buddhistic painting, made back-adherent paper of the support layer proper to it, tested its compatibility, and then concluded as follows. 1. The section structures of buddhistic painting is consisted of the pigment layer, silken-ground layer of silk and the support layer of Korean hand made paper, it could be recognized that buddhistic painting in 19th century was basically composed of the pigment layer, the silken-ground layer and the support layer. Moreover the pigment layer and the silken-ground layer got adhered with glue, and sheets of support layers got back adhered with paste. 2. The support layer of buddhistic painting consisted of 5 layers and two kinds of paper were used for them. The first and second layers were composed of Korean hand made paper made of pure paper mulberry bast fibers, and the rest of them of paper that paper mulberry bast fibers were mixed into recycled hemp fibers. Though it is difficult to assert without the security of more data, finding out the then situation through the qualities of materials, it was presumed that the society in 19th century was suffered from economical difficulties and the operation of the paper industry of temples was rather difficult and so low-qualitative recycled hemp fibers might used for back-adherent paper. 3. Considering tension between silken-ground layers and support layers of this materials, newly made back-adherent paper was used for repair, and then I could conform that it was proper to back-adherent paper for repair.

• Korean Journal of Environment and Ecology
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• v.21 no.1
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• pp.93-100
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• 2007

This study was based on the breeding process of the Pacific Reef Herons (Egretta sacra) bred in Aewol-eup, Jeju Island, for two years from February 2004 to June 2005. The clutch size of the pacific reef herons was $3.24{\pm}0.75$(N=17, range: $2{\sim}4$), and the egg-laying was at dawn or night intervals of one to three days. The major diameter of the egg(N=39) was $46.73{\pm}1.91mm$, the minor diameter thereof $34.06{\pm}0.83mm$, the weight thereof $27.67{\pm}3.12g$, and the thickness of the egg shell thereof $0.26{\pm}0.03mm$. In relation to the breeding cycles of the Pacific Reef Herons, the nesting or nest repairing was made from February to the end of April each year, the egg laying from the beginning of March to the beginning of May, the hatching from the beginning of April to the middle of May, and the nest departure from the middle of May to the end of July. The supplement brood was started immediately from May to June when the first brood had failed. The incubation period was $28.17{\pm}4.12(N=6)$ days, and hatched asynchronously. The fledgling period was $40.00{\pm}6.84(N=5)$ days, and bill, wing, tarsus and weight developments of early hatched nestlings were the fastest among the same brood. Compared with other egret species, the egg laying period of the Pacific Reef Heron was faster than that of the Black-crowned Night Heron, Little Egret and Great Egret, but later than that of Grey Heron, in Korea.

• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.209-216
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• 1974

Life history and control methods of Aphanostigma iakusuiense Kishida were studied during April to November, 1974, in the Naju pear orchard area, Cholla Namdo. The results are summarized as follows: 1. More than $60\%$ of wintering eggs were found at the height of 1.5 to 2.0m from the soil surface, with approximately $10\%$ at 0.5 to 1.5m and 1.5 to 2.5m respectively. 2. There was little difference in the size of egg masses and hatching ratio $(12.7-13.7\%)$ between the varieties of host trees, Mansamkil and Kooksoo. 3. Hatching was not observed until April 6, but hatches of $12.8\%$ on April 13 and $90.6\%$ on May 4 were found. 4. During the hatching season in early spring, 8 chemicals were applied to test effectiveness of control. C8514, Metasystox, Acar 338, and Parathion were more effective than either Sevin or Malix for control of this insect. 5. Highest populations of pear phylloxera ocurred from August 20 to September 20 at which time levels of eggs and larvae were simillar in abundance. 6. In tests for control of this insect after in paper bags, DDVP, Loxon, C8514, Sevin, and Binapacryl were more effective than either EPN or Otran. 7. Predacious mite, Protolaelape pygmaeus Miller, and several species of lady beetles (Coccinellidae) preying on this insect as natural enemies were collected. The predation ratio of mites varied according to region: that is 0.77 to $18.6\%$ in Bia Orchard; $7.88-48.7\%$ in Noan Orchard and almost none in Youngsanoo Orchard. 8. The varietal difference in fruit damage by this insect was in the order of Choseng Chuck, Kooksoo, followed by Sin Ko, Mansamkil, Keumchon Choo, and Changsimrang.

• Journal of Oral Medicine and Pain
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• v.26 no.2
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• pp.107-114
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• 2001

Oral malodor is a problem that traverses history, culture, race and sex. But, up to the present the study on prevalence of oral malodor in normal popualtion is short, especially there is no study on oral malodor prevalence in Korean. In our study, we investigated self-evaluation of oral malodor, self-rating intensity of oral malodor, patients efforts for curing their oral malodor, and degree of satisfaction with their efforts. Investigation was carried out on 368 public Koreans resident in a big city(174 males, 194 females), by method of self-reporting to prepared questionnaire. There was no difference in self-reporting prevalence of oral malodor in sexes(57.5% in male, 58.8% in female), and the prevalence rate was increased with aging. Self-rating intensity of oral malodor in oral malodor patients group(by self-reporting) was ranked in order of slight, weak, middle, strong in both sexes, but the number of self-rating strong female group is significantly larger than that of self-rating strong male group(9.3% in male, 17.9% in female). In question on duration of oral malodor, most subjects answered that their oral malodor was developed in certain circumstances(61.3% in male, 76.3% in female), and oral malodor-developing circumstances was ranked in order of in the early morning, in hunger state, in fatigue, in stressful situations. Subjects effort for curing their oral malodor was ranked in order of more tooth brushing, gum chewing, use of commercial product for oral hygiene, visit dental clinic, and rates of no effort subjects were 15.3% in males and 10.7% in females. The degree of satisfaction with their efforts for curing their oral malodor was very low, only 5.6% of males and 6.6% of females were answered that there were satisfactory improvement in their oral malodor. Collectively, our result revealed that prevalence of oral malodor in public Koreans and their interest in oral malodor were much higher than our anticipation, and that patients satisfaction with improvement in oral malodor was short of their expectations. Considering the life quality of patients suffering from oral malodor, we conclude that developments of more improved diagnostic tools and treatment methods for oral malodor is indispensable in future.

• The Korean Journal of Air & Space Law and Policy
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• v.29 no.1
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• pp.97-126
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• 2014

October 4, 1957 the Soviet Sputnik 1 was launched into space the first time in the history of mankind. After launching, the realm of humankind was expanded to space. Today all countries of the world wage a fierce competition in order to utilize space for various purposes. World powers of space such as United States, Russia, China, and Japan, put reconnaissance satellites and ocean surveillance satellites into orbit, being able to easily see equipment and troops movement on earth. Each country makes efforts to occupy space assets through the militarization of space and expand national interests. Recently private companies or individuals involved in commercial space activities are becoming more prevalent. Thus, in addition to space activities for military purposes, commercial space activities become widespread. Individuals and private companies as well as nations are also involved in space activities. Outer space is not the monopoly of space powers such as the United States and Russia. The whole human race can benefit from free access to space, being the common heritage of mankind. In particular, outer space becomes an indispensable element of military activities and human life. Many countries are now entering space development, putting a lot of budget into new development programs. Republic of Korea also built the Narodo Space Center, starting its space development with budget and manpower. We have to find out ways to use space not only for military purposes but also for commercial space activities that can contribute to the national economy. In addition, through the joint efforts of the international community, we have to make efforts for preservation and peaceful use of space. Various issues relating to space activities and research should be studies in order to contribute to the progress of humanity. Those issues include the definition of outer space, space debris reduction and environmental conservation issues, non-bind measure cooperation - European International Code of Conduct, space law and national legislation related empowerment issues, arms control measures in space, and restrictions on the use of nuclear fuel. We also need to be involved in the discussion of those issues as one of responsible space countries. In addition, we try to find out regional cooperation schemes such as the ESA in the Europe actively. Currently in the Northeast Asia, cooperation bodies led by Japan and China respectively, are operated in the confrontational way. To avoid such confrontation, a new cooperative body needs to be established for cooperation on space exploration and information. The system to allow the exchange of satellite information for early warning of natural disasters needs to be built as well. In addition, efforts to enhance the effectiveness of the relevant international treaties on space, and fill in the blanks in international space laws should be made at the same time. To this end, we have to do a leading role in the establishment of standards such as non-binding measures (resolution) - Code of Conduct, being discussed in the UN and other organizations, and compliance with those standards. Courses in aerospace should be requires in law schools and educational institutes, and professional manpower need to be nurtured. In addition, the space-related technology and policy needs to be jointly studied among the private, public, and military groups, and the cross exchange among them should be encouraged.

• The Korean Journal of Zoology
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• v.9 no.1
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• pp.7-15
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• 1966

In a previous paper, the dirunal and monthly changes of the tidal flat temperature and chlorinity were observed. In this paper the resistance of the young short necked clam in various growth stages to the temperature, to the chlorinity and to the exposure were studies. The young clam used were in early (E), medium (M) and late (L) young stages whose shell lengths were 2.0-3.5mm, 9.0-11.0mm. and 14.0-16.0mm., respectively. The results were : 1. At various sea water temperatures , the chlorinity resistance of the young clam was directly proportional to the shell length. 2. When both inadequate sea water temperature and abnormal chlorinity are simultaneously applied, the resistance of these young clams was more markedly reduced than the case of applying either one of these conditions. 3. In clams of M and L, no lethal effect were observed when daily immersion of four to eight hours for a week into the sea water of any concentration of chloriity at 26-34$^{\circ}C$, whereas in E, 37-90% of mortalities were obtained by immersion of eight hours daily into both the fresh water and the sea water of higher chloriniites (more than 23.5$\textperthousand$ Cl) at the same temperature above. 4. The lower critical thermal maximum for lethal to the young clam was 38$^{\circ}C$. With four hours immersion daily at the water temperature of 38$^{\circ}C$, the mortalities of E, M and L to the lower chlorinities (less than 6.7$\textperthousand$Cl) were 100, 70-100 and 27-37% respectively ; to the higher chlorinities (more than 23.5$\textperthousand$Cl) 10-70, 10-37 and 3 % respectively ; to the normal range of chlorinities (13.4-16.8$\textperthousand$Cl) 0-13, 3 and 0 % respectively. 5. No lethal effects were observed in E and M clams immersed continuously for seven days in sea water with chlornities of 7.2 -21.7$\textperthousand$Cl at 18-24$^{\circ}C$, while notable mortalities were observed in E which had been kept at lower (less than 4.8$\textperthousand$ Cl) and higher (more than 24.1$\textperthousand$ Cl) chlorinites. 6. Although the resistance of the young clam to the chlorinity may have to be related closely to the life history of the clam prior subject to the experiment, the adapted chlorinity range was 7.2-19.3$\textperthousand$ Cl and the optimum range was 13.4-16.8$\textperthousand$Cl. 7. Remarkable lethal effects were observed for the E and M clams to the exposure temperature of 38$^{\circ}C$ whereas the L and had no such fatal results.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.2
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• pp.61-67
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• 2018

Jens Jensen was an American landscape architect and early conservationist who pioneered a unique naturalistic landscape style. The purpose of the present study is to study Jensen's life, careers, design philosophy, and his contributions to the history of landscape architecture. Inspired by nature, Jensen worked closely with native plants, local materials, curvilineal and circular forms, and native scenery. His pioneering work in the Chicago's West Parks, including the design of Columbus Park and Humboldt, Garfield and Douglas Parks, was informed by his philosophical belief in the humanizing power of parks. In summary, first, Jensen played a prominent role in the creation of a unique native landscape style respecting regional landscape. Second, as a devoted conservationist and educator he organized conservation movements preserving landscape heritage and founded a education institution. Third, as a social reformer he emphasized the value of parks and nearby nature for urban citizens and children. Jensen's visions and philosophies have influenced on recent naturalistic landscape style and conservation efforts to preserve cultural landscape and natural environment.