• Journal of the Korean Regional Science Association
• /
• v.39 no.4
• /
• pp.53-71
• /
• 2023

This study aims to identify the contribution of factors to employment growth over the past 20 years (1996-2016) for seven metropolitan areas in Korea. For this purpose, we performed a multifactor partitioning (MFP) analysis based on the business survey data provided by Statistics Korea. The key findings of the analysis are as follows. First, over the long run, the region effect is dominant in metropolitan employment growth, followed by the industry mix effect. On the other hand, the dynamic MFP findings suggests that future regional employment disparities are likely to be explained by industry structure. Second, the gender mix and decent job mix effect do not significantly contribute to regional employment growth. However, the contributions of individual factors are not invalid, and it is possible to infer a pattern of declining employment for men-permanent workers and increasing employment for women-contingent workers. These results indicate the importance and necessity of employment policies that can promote structural transition in regional industries and qualitative growth accompanied by employment stability.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.34 no.2
• /
• pp.48-54
• /
• 2024

During the Hg₂Br₂ physical vapor transport process with self-diffusion, it is concluded that for 10^-3g₀≤ g ≤ 1g₀ the thermal buoyancy driven convection is dominant in the vapor phase; at the gravitational level of g = 10^-4g₀, the transition region from the convection to diffusion occurs; for 10^-6g₀ ≤ g ≤ 10^-5g₀, the diffusion mode is predominant. The total molar flux of Hg₂Br₂ decays exponentially with the decreasing of one tenth of gravitational magnitude. For 10℃ ≤ ΔT ≤ 50℃, the total molar flux increases linearly and directly with the temperature difference between the source and crystal regions.

• Journal of Korean Neurosurgical Society
• /
• v.67 no.1
• /
• pp.6-13
• /
• 2024

The integrity of the high cervical spine, the transition zone from the brainstem to the spinal cord, is crucial for survival and daily life. The region protects the enclosed neurovascular structure and allows a substantial portion of the head motion. Injuries of the high cervical spine are frequent, and the fractures of the C2 vertebra account for approximately 17-25% of acute cervical fractures. We review the two major types of C2 vertebral fractures, odontoid fracture and Hangman's fracture. For both types of fractures, favorable outcomes could be obtained if the delicately selected conservative treatment is performed. In odontoid fractures, as the most common fracture on the C2 vertebrae, anterior screw fixation is considered first for type II fractures, and C1-2 fusion is suggested when nonunion is a concern or occurs. Hangman's fractures are the second most common fracture. Many stable extension type I and II fractures can be treated with external immobilization, whereas the predominant flexion type IIA and III fractures require surgical stabilization. No result proves that either anterior or posterior surgery is superior, and the surgeon should decide on the surgical method after careful consideration according to each clinical situation. This review will briefly describe the basic principles and current treatment concepts of C2 fractures.

• Clinical and Experimental Reproductive Medicine
• /
• v.50 no.4
• /
• pp.253-261
• /
• 2023

Objective: Azoospermia (the total absence of sperm in the ejaculate) affects approximately 10% of infertile males. Despite diagnostic advances, azoospermia remains the most challenging issue associated with infertility treatment. Our study evaluated transition nuclear protein 2 (TNP2) and synaptonemal complex protein 3 (SYCP3) polymorphisms, azoospermia factor a (AZFa) microdeletion, and gene expression levels in 100 patients with azoospermia. Methods: We investigated a TNP2 single-nucleotide polymorphism through polymerase chain reaction (PCR) restriction fragment length polymorphism analysis using a particular endonuclease. An allele-specific PCR assay for SYCP3 was performed utilizing two forward primers and a common reverse primer in two PCR reactions. Based on the European Academy of Andrology guidelines, AZFa microdeletions were evaluated by multiplex PCR. TNP2, SYCP3, and the AZFa region main gene (DEAD-box helicase 3 and Y-linked [DDX3Y]) expression levels were assessed via quantitative PCR, and receiver operating characteristic curve analysis was used to determine the diagnostic capability of these genes. Results: The TNP2 genotyping and allelic frequency in infertile males did not differ significantly from fertile volunteers. In participants with azoospermia, the allelic frequency of the SYCP3 mutant allele (C allele) was significantly altered. Deletion of sY84 and sY86 was discovered in patients with azoospermia and oligozoospermia. Moreover, SYCP3 and DDX3Y showed decreased expression levels in the azoospermia group, and they exhibited potential as biomarkers for diagnosing azoospermia (area under the curve, 0.722 and 0.720, respectively). Conclusion: These results suggest that reduced SYCP3 and DDX3Y mRNA expression profiles in testicular tissue are associated with a higher likelihood of retrieving spermatozoa in individuals with azoospermia. The homozygous genotype TT of the SYCP3 polymorphism was significantly associated with azoospermia.

• Korean Journal of Heritage: History & Science
• /
• v.50 no.3
• /
• pp.4-29
• /
• 2017

The purpose of this study is to grasp the commencement date of Korean-type bronze dagger through the chronology of Chinese data. It focuses on the fact that the same section polishing technique appears both in Korean type bronze dagger and Dongzhou type bronze dagger. Dongzhou type bronze dagger in Anqiu Shandong, in which A1 type section polishing technique is observed, was said to have been collected remains in 1958, but the clear excavation cannot be identified. Therefore, this study presents Tomb No.1 Zuojiawa Jinan, Dongzhou type bronze dagger, and associated products. As associated products, bronze weapon and bronze ware were excavated, whose periods are estimated to be in the Spring and Autumn period, the transition period of Warring States, and the former part of the China's Warring States. Accordingly, the Korean bronze dagger, excavated in the remains of the Han Peninsula appears to have run parallel with the Dongzhou type bronze dagger of the A1 type section polishing technique, excavated in China for a fixed period. In addition, the chronology of Tomb No. 61MI grave in Wanrongmiaoqian, Shanxi is estimated to range from the former part to the middle part of the China's Warring States, which is identified to be connected to the A1 type section polishing technique. Examining the data of the relative date, we can find out that the Commencement Period of the Korean type bronze dagger Culture is seen to be the transition period and the former part of the China's Warring States, which is estimated to be the 5th and 4th centuries BC. This chronology is followed by Tomb No.6512 Zhengjiawazi Shenyang, recorded as the 6th century B.C. which reveals that Liaoning type bronze dagger culture and Korean-typed Bronze Dagger Culture are naturally connected. Furthermore, the A1 type section polishing technique was distributed in the southwestern area of the Korean peninsula and Shandong, China, while the A2 type section polishing technique was distributed in the southern area of the Korean peninsula, Shanxi-Province in China, and Northern Kyushu region in Japan. Seen from the weapon-shaped bronze ware of the section polishing technique, Shanxi area(Central Plains area), China. the southwestern area of the Korean peninsula (northwest area), and Northern Kyushu region in Japan are set up as one traffic road(spreading route). This demonstrates that the section polishing technique emerged around the Han Peninsular, spreading the technique regionally.

• Journal of the Korean Vacuum Society
• /
• v.20 no.6
• /
• pp.461-467
• /
• 2011

The valence band maximum and the conduction band miminum of GaAs, GaSb, InAs, and InSb (constituent binaries of the quaternaty alloy $Ga_xIn_{1-x}Sb_yAs_{1-y}$) are calculated by using TB analytical approach method. The band alignment types of their heterojunctions are determined directly from their relative position of band edges (VBM and CBM). For example, the GaAs/InAs, GaAs/InSb, and GaSb/InSb are in a type-I, the GaAs/GaSb in a type-II, and the GaSb/InAs and InSb/InAs in a type-III, respectively. The composition dependent VBM and CBM for the $Ga_xIn_{1-x}Sb_yAs_{1-y}$ alloy are obtained by using the univeral tight binding method. For the alloyed heterojunctions, the band alignments can be controlled by changing the composition which induce a band type transition. For the alloy $Ga_xIn_{1-x}Sb_yAs_{1-y}$ lattice mathced to GaSb, the type-II band alignment in the region of $x{\leq}0.15$ is changed to the type-III in the region of $x{\geq}0.81$. On the other hand, the alloy $Ga_xIn_{1-x}Sb_yAs_{1-y}$ lattice mathced to InAs has the type-II band alignment in the region of $x{\leq}0.15$ and the type-III band alignment in the region of $x{\geq}0.81$, respectively.

• Journal of Environmental Impact Assessment
• /
• v.25 no.4
• /
• pp.233-247
• /
• 2016

The purpose of this study is to offer the basic data for management of National Park by surveying and analysing the change of flora of damaged lands in Juwangsan National Park, Korea. In cause of occurring the damaged lands, site-1 was the vegetation damage by stamping, the removing Gwangamsa of site-2, 3, 4 and the removing Naewon village of site-5, 6, 7. Whole sites are caused by the artificial disturbance and interference. The numbers of flora were summarized as 135 taxa including 52 families, 109 genera, 116 species, 2 subspecies and 17 varieties in whole sites. The status of flora by sites, site-6 is the largest number of 52 taxa, site-1 is the lowest of 23 taxa. The rare plant is 1 taxa, 4 taxa of endemic plants, 10 taxa of specific plants by floristic region, 9 taxa of naturalized plants and 1 taxa of invasive alien plant. In the results of analysis about the change of coverage ratio, for this shrub layer, site-7 was changed to the most $0%{\rightarrow}50%$, and the herb layer, site-5 was changed to the most $75%{\rightarrow}95%$. In case of the change of species numbers, most sites tended to increase in the sites introduced different species or generated by the growth. It is contemplated that is similar to the restoration with the surrounding natural vegetation that is in progress is a transition occurs with the passage of time. In the dominant species, the shrub layer is Fraxinus sieboldiana, Lespedeza bicolor, Rhus javanica, Lespedezamaximowiczii, Salix koreensis and Zelkova serrata, and Miscanthus sinensis var. purpurascens, Oplismenus undulatifolius, Artemisia princeps, Bothriochloa ischaemum and Erigeron annuus of herb layer. In the results of analysing Naturalized Index(NI) and Urbanized Index(UI), NI was increased or decreased this phenomenon with the lapse of time, UI was the most increase. In particular, the increase in UI is due to the transition process, the pioneering plant, naturalized plant was imported to continue.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.14 no.4
• /
• pp.196-206
• /
• 2012

Studies of seasonal changes in $C_3/C_4$ mixed communities are rare, particularly in Asian summer monsoon climate zones. In our present study, seasonal changes in the profile and coverage of $C_3$ and $C_4$ plants were investigated in 2009 in Haenam, Yeongdong and Cheorwon regions of South Korea (all at different latitudes). The aim was to estimate the impacts of temperature and sunshine duration on species composition and transition timing of the $C_3$ and $C_4$ plants. From our results, the number of $C_3$ plants was found to increase from early spring to mid-May, and then decrease again until September in the Haenam and Yeongdong regions, but continuously increase from early spring to September in the Cheorwon region under relatively low summer temperatures. On the other hand, the number of $C_4$ plants increased from June or July to September in all three regions. These seasonal changes in species number and ratio have a direct impact upon species diversity which is highest when there are no dominant species. The relative coverage and relative summed dominance ratio (SDR') of the $C_3$ plants decreased from spring to autumn, but increased for the $C_4$ plants during this time in an exponential fashion with increasing accumulated temperature and sunshine duration. The transition timing from $C_3$ to $C_4$ plants occurred when the sum of sunshine duration for the days with daily mean temperature above $5^{\circ}C$ was 1017 hrs for the SDR'.

• Journal of the Geological Society of Korea
• /
• v.54 no.5
• /
• pp.489-499
• /
• 2018

A series of geological events such as the formation of the Antarctic continental ice sheets, the changes in ocean circulation and a mass extinction after the onset of Oligocene has been studied as major concerns by various researches. However, paleoclimatic and paleoceanographic changes during the most period of Oligocene since the Eocene-Oligocene transition (EOT) still remains unclear. Especially, although the late Oligocene warming (LOW) has been assessed as the largest period in the paleoceanographic changes, the detailed understanding on the changed components is very low. The purpose of this study is the reconstruction of the paleoceanographic history during the late Oligocene using core sediments from IODP Expedition 342 Site U1406 performed in J-Anomaly Ridge in North Atlantic. Because North Atlantic deep water (NADW) has flowed southward through the study area since the early Oligocene, this area has been considered to an important location for studies on the changes of NADW. The core sediment analyzed in this study were deposited from about 26.0 to 26.5 Ma as evidenced by both of onboard and shore-based paleomagnetic data, and this is corresponded to the earliest period of LOW. The sediment profile can be divided into three Units (Unit 1, 2 & 3) based on the changes in both of total number and test size of Oridorsalis umbonatus as well as grain size data of clastic sediments. Unit 2 represents largest values in these three data. Because the total number, test size of O. umbonatus and grain size can be proxy records on the oxygen concentration and circulation intensity of deep water, we interpreted that Unit 2 had been deposited during the period of relatively strengthened NADW. Previous Cibicidoides spp. stable isotope results from the low latitude region of the North Atlantic also support our interpretation that is the intensified formation of NADW during the identical period. In conclusion, our results present a new evidence for the previous ideas that the causes on LOW are directly related to the changes in NADW.

• International Commerce and Information Review
• /
• v.15 no.3
• /
• pp.25-39
• /
• 2013

This study is to analyze Gwangju's trade structures with China, Japan and the United Sates, and to contribute, through clarification of product competitiveness, to minimizing free-trade-induced costs as well as maximizing profits from free trade. To obtain this study purpose, two export competitiveness indicators are used; they are Trade Specialization Index (TSI) and Grubel & Lloyd(GL) Index. Intra-industry trade is examined to see if there exists a technological gap between nations. Intra-industry trade is divided into two; Low Quality Vertical Intra-Industry Trade (LQVIIT) and High Quality Vertical Intra-Industry Trade (HQVIIT). Gwangju's trade with China is HQVIIT; Gwangju exports high-quality and high-priced items to China, and imports low-quality and low-priced ones. On the other hand, Gwangu's trade with Japan is mainly LQVIIT; Gwangju exports low-quality and low-priced processed stuffs to Japan, and imports high-quality and high-priced ones from Japan. While Korea-US is mainly of both high-quality and low-quality Vertical Intra-Industry Trade; Gwangju exports low-quality and low-priced items as well as high-quality and high-priced items to the USA. Based on the analysis result, export marketing strategies are presented as follows: the transition to high value-added export system, the local entry networking, government support for trade exhibition, offer of special program on local small businesses.