• 한국대기환경학회지
• /
• 제26권5호
• /
• pp.490-498
• /
• 2010

HCFC-22 (chlorodifluoromethane, $CHClF_2$), one of the major components in various refrigeration, is emitted mostly from developing countries, as its consumption is not limited until 2013 by the Montreal Protocol. In addition, HFC-23 (trifluoromethane, $CHF_3$), a by-product in the manufacture of HCFC-22, is also a powerful greenhouse gas. Here, we discuss the regional emission characteristics of these compounds based on high-frequency in-situ measurements using the "Medusa" GC-MS system. HCFC-22 and HFC-23 baseline concentrations measured at Gosan (Jeju Island, Korea) from November 2007 to December 2008 increased by 1.8 ppt/yr and 0.6 ppt/yr, respectively. Pollution events of these compounds were observed, very frequently (e.g., ~2~3 times) at Gosan than baseline levels. All the measurement data were divided into four groups by simultaneously considering the ratio (HFC-23/HCFC-22) and concentration (HCFC-22) at Trinidad Head (TH, California, USA). The residence time of trajectories were then analyzed in each of the four groups. The results exhibited the existence of a strong correlation with air mass origin for each group: 1) Air masses originating from Siberia in the north and from the Pacific in the south had ratios of 0.08~0.12 and concentrations of 196.9~254.3 ppt which is highly comparable to background air at TH. 2) Air masses passing over the Southern China exhibited similar ratios but higher HCFC-22 concentrations. 3) Air masses passing over the Northern China had ratios of 0.12~0.21. 4) Air masses passing over Korea and/or Japan had ratios of 0.01~0.08. Our results suggest that the HFC-23/HCFC-22 ratio can be used as a good indicator for the assessment of the pollution with Chinese origin. We also confirmed differences in air masses traveling over Northern and Southern China, most likely due to differences in air mass travelling speed over these regions before arriving at Gosan. This signature may be treated as one of the critical components in identifying the emission sources from different parts of China.

• 한국인구학
• /
• 제26권2호
• /
• pp.111-145
• /
• 2003

이 연구는 개혁개방정책 이후 중국 내 조선족이 보인 사회인구학적 행태의 변화를 설명하기 위한 것이다. 시장경제체제의 도입과 한중 국교수립 이후 조선족사회는 출산력수준의 급격한 저하와 인구구조의 고령화로 매우 급격한 변화를 겪고 있다. 조선족의 인구행태와 인구구조의 이러한 변화는 한족에 비해 두드러지게 나타난다. 중국 내 조선족인구가 가장 밀집되어 거주하고 있는 연변지역의 조선족사회는 최근 절대인구규모의 감소추세를 보이고 있다. 아울러 시장경제의 도입 이후 이동성향이 높아지고 통혼권과 거주지역이 확산되며. 조선족학교를 통한 민족교육이 급격히 위축되는 추세를 보인다. 그리고 이에 따라 조선족사회의 사회적 통합과 문화정체성이 약화되고 중국 내 소수민족사회로서의 위상도 점차 약화되는 과정에 있다. 연변 조선족사회의 사회인구학적 변화와 위기상황에 대한 설명을 위해 이 연구는 연변조선족자치주의 1990년과 2000년 인구센서스 자료와 각종 통계자료를 활용하였다. 또한, 이 연구에서는 인구센서스를 통하여 드러난 조선족인구의 연령구조가 매우 불규칙적이라는 점을 감안하여 1990년과 2000년 인구센서스 자료의 신뢰성과 정확도를 재검토하는 작업도 이루어졌다.

• 분석과 대안
• /
• 제7권3호
• /
• pp.1-26
• /
• 2023

This article will analyze and forecast important variables and dynamics in global power politics after the war in Ukraine. It tries to use several perspectives to analyze international relations, particularly liberal internationalism and structural realism. In short, core variables are as follows; First, how is the US-led liberal international order and globalization being adjusted? Second, how will the U.S.-China strategic competition, which is the biggest and structural variable, cause changes in the international order in the future? The third variable, how stable are Sino-Russia relations in the context of a structuring U.S.-China-Russia strategic new triangle? Fourth, to what extent will third middle hedging states outside the U.S. and China be able to exercise strategic autonomy in the face of multipolarization? To summarize, the first of these four variables is the largest basic variable at the global political and economic level in terms of its impact on the international community, and it has been led by the United States. The second variable, in terms of actors, seems to be the most influential structural variable in global competition, and the US-China strategic competition is likely to be a long game. Thus the world will not be able to escape the influence of the competition between the two global powers. For South Korea, this second variable is probably the biggest external variable and dilemma. The third variable, the stability of Sino-Russia relations, determines balance of global power in the 21st century. The U.S.-China-Russia strategic new triangle, as seen in the current war in Ukraine, will operate as the greatest power variable in not only global power competition but also changes in the international order. Just as the U.S. is eager for a Sino-Russia fragmentation strategy, such as a Tito-style wedge policy to manage balance of power in the early years of the Cold War, it needs a reverse Kissinger strategy to reset the U.S.-Russia relationship, in order to push for a Sino-Russia splitting in the 21st century. But with the war in Ukraine, it seems that this fragmentation strategy has already been broken. In the context of Northeast Asia, whether or not the stability of Sino-Russia relations depends not only on the United States, but also on the Korean Peninsula. Finally, the fourth variable is a dependent variable that emerged as a result of the interaction of the above three variables, but simultaneously it remains to be seen that this variable is likely to act as the most dynamic and independent variable that can promote multilateralism, multipolarization, and pan-regionalism of the global international community in the future. Taking into account these four variables together, we can make an outlook on the change in the international order.

• 지역사회간호학회지
• /
• 제22권3호
• /
• pp.234-240
• /
• 2011

Purpose: The purpose of this study was to compare exercise performance with related factors between Korean and Korean-Chinese nursing students. Methods: This study used a cross-sectional comparative survey method. One hundred sixty five Korean nursing students in Seoul, South Korea and 161 Korean-Chinese nursing students in Yanbian, China were recruited through convenience sampling. They were at the age of 19-26. Exercise performance and exercise-related factors were measured using the exercise performance degree scale and the scales of self-efficacy, perceived barriers, perceived benefits, and affection related to exercise. Results: No significant difference in exercise performance was seen between the two groups. Self-efficacy and perceived benefits related to exercise performance were significantly higher in the Korean nursing students than in the Korean-Chinese nursing students. However, there were no significant differences in affection and perceived barriers related to exercise. Conclusion: We suggest that the reasons for the differences in self-efficacy and in perceived benefits between these two groups need to be explored though future studies. We suggest more studies comparing different groups having the same ethnicity as Korean but who were born into different societies to give answers regarding the influence of immigrated transition on health.

• 한국환경보건학회지
• /
• 제36권5호
• /
• pp.360-372
• /
• 2010

Concentrations of ambient air particles such as total suspended particulates (TSP), particulate matter $(PM)_{10}$, and $PM_{2.5}$, were monitored simultaneously from May to June, 2007, at four locations at Alashan and Beijing in China, and Seoul and Gosan in South Korea. These monitoring sites are in the pathway of Asian dust (AD) storms traveling from China to the Korean peninsula. An AD event was observed in the Korean peninsula on May 25-26. During the sampling period, the average concentrations of TSP and PM10 were each higher than $150\;{\mu}g/m^3$ in Alashan and Beijing, but not in Seoul and Gosan. The concentration of TSP in Alashan (where the dust storm originated) on the day of the AD event reached $1824.7\;{\mu}g/m^3$, this being the highest concentration of air particles observed during the sampling period. The level was decreased to 15% of this ($274.7\;{\mu}g/m^3$) in Seoul and to 8.7% ($159.0\;{\mu}g/m^3$) in Gosan when the AD was observed two days later in Korea. Gosan, a representative background site in East Asia, displayed the lowest concentration of particles, with this maximal TSP concentration of $159\;{\mu}g/m^3$. Inorganic element contents in the air particles were also measured, and the concentrations in the four different regions compared. Concentrations of anthropogenically-enriched heavy metals in $PM_{10}$ and $PM_{2.5}$, such as lead, arsenic, cadmium, and mercury, were higher in the metropolitan cities of Beijing and Seoul compared to non-industrialized regions of Alashan and Gosan. However, the concentrations of inorganic soil elements including iron, magnesium, aluminum sodium, and manganese, were higher in Alashan compared to those in other sampling sites.

• 한국어류학회지
• /
• 제21권sup1호
• /
• pp.73-73
• /
• 2009

The modern cartilaginous fishes, class Chondrichthyes, are small group of Pisces, and comprisingmore 1,000 described valid species, and including approximately 190 genera, 55 families, and 15 orders. The Chondrichthyes consists of two subclasses, the Holocephali (chimeras) and the Elasmobranchii(sharks and rays). The dominant subclass Elasmobranchii includes sharks (Selachii) and rays (Batoidea), the former is more diverse than the latter in higher taxa (order, family, genus) but has fewer species. The Batoidea, batoids or rays, has long been recognized as monophyletic, however, the interrelationships of the groups are problematic and uncertain. In order to review biodiversity and systematics of batoids, valid species name and supraspecific taxa from the published materials are studied. Batoids (including sawfishes, Pristiformes; electric rays, Torpediniformes; stingrays, Myliobatiformes; skates, Rajiformes; wedgefishes, Rhiniformes; and guitarfishes, Rhinobatiformes) is speciose and worldwide with about 580 species in 4 to 6 orders, 17 to 19 families, and about 75 genera. In East Asian waters, the previous records of the Batoidea reveal about 170 species belonging to 41 genera, 18 families, 6 orders. The largest group of batoid fauna in the area is order Myliobatiformes comprising about 80 species, 16 genera of 7 families. The predominant families are Dasyatidae (whiptail stingrays: 46 spp. of 6 genera), Arhynchobatidae (softnose skates: 26 spp. of 3 genera), and Rajidae (skates: 21 spp. of 6 genera). The predominant genera are Bathyraja (softnoseskates: 20 spp.), Himantura (whiprays:19spp.), and Dasyatis (fantailstingrays: 18 spp.). There are 23 species in the Yellow Sea, 70 species in the East China Sea, 82 species in the South China Sea, and 58 species in the North Pacific coast of Japan. Batoid fauna from the East Sea (Sea of Japan) is the poorest of the five regions, consisting of 14 species. Korean waters include only 28 species, 16 genera, 10 families and 5 orders of batoids. Two species is torpediniforms, 4 rhinobatiforms, arhynchobatiforms, 11 rajiforms and 10 myliobatiforms. By the earlier works, the systematics and a check list of the valid species of batoids will be presented.

• Journal of Korea Trade
• /
• 제26권5호
• /
• pp.106-124
• /
• 2022

Purpose - The increasing share of Korean private label products (PLPs) in the domestic market helped generate lucrative revenue. In recent years, major South Korean retailers have begun to cast their sights on overseas markets and actively export their PLPs. In China, the proportion of private label fresh food (PLFF) is gradually expanding amid the development of the new retailing model. A profound understanding of the relationship between private label fresh produce and purchase intention may be the answer to helping Chinese retailer private labels expand supply chains in Korea. This study, taking Chinese retailers as an example, examines the impacts of selection factors of private label fresh food and perceived value on purchase intention. Apart from that, the relationship between the selection factors and purchase intention will be analyzed with perceived value as a mediator. Design/methodology - This work aims to empirically analyze the purchase intention of private label fresh food using statistical analysis. In this study, a hypothetical causal model consisting of 6 latent variables and 24 measured variables is developed based on the literature review. To validate the research hypotheses and the research model, SPSS23.0/AMOS23.0 is used to analyze factors such as validity and reliability, as well as structural equation modeling. Findings - The hypothetical model established in this study is of general applicability. In respect to PLFF, perceived value, while significantly influencing purchase intention in combination with four selection factors (perceived quality, perceived price, brand trust, and store image), mediates partially between the first three factors and purchase intention, which rules out the impact and mediating effect of store image on purchase intention. Originality/value - These research results, as helpful insights into the present circumstances of Chinese PLFF in the domestic market, provide useful information and guidance for Korean retailers and service providers to innovate production and service, as well as develop marketing and promotion strategies, so that they can shift private label goods with advantages from domestic demand to export, thus increasing overseas profitability. Further, this work will also contribute to relevant research.

• Fisheries and Aquatic Sciences
• /
• 제26권2호
• /
• pp.69-86
• /
• 2023

The bioactive secondary metabolites produced by sea cucumbers are very diverse with differences in composition, linkages, molecular weight, and various functional properties. Due to their physicochemical properties, these bioactive molecules in sea cucumbers have found applications in various market segments such as functional foods and cosmetics. Sea cucumber side dishes are a prominent food item in traditional cuisine in East Asian countries such as South Korea, China, and Japan. In addition, many studies have reported that the consumption of sea cucumbers can reduce the risk of cardiovascular disease, the pathogenesis of cancer cells, chronic inflammatory diseases, etc. In particular, many studies have recently reported the potential of sea cucumbers to develop functional products to reduce inflammation, oxidative stress, diabetes, and cancer. Additionally, these bioactive properties associated with sea cucumbers make them ideal compounds for use as functional ingredients in functional food products. However, no report has yet reviewed the properties of sea cucumbers related to functional foods. Therefore, in this review, the primary focus is given to collecting published scientific data (from 2019 to 2023) on the bioactive properties of sea cucumbers relevant to the functional food industry.

• 한국해양환경ㆍ에너지학회지
• /
• 제10권2호
• /
• pp.67-85
• /
• 2007

황해 및 동중국해에 있어서 하계 조석, 담수유입량과 풍향 풍속 변화에 따른 잔차류와 샨샤댐 건설 전과 후 양쯔강의 유량 변동에 따른 저염분 확산과 바람의 영향 등을 해석하고, 평가하였다. 3차원 해수유동모델에 의해 각 분조($M_2,\;S_2,\;K_1$과 $O_1$)의 정량적 그리고 정성적 측면의 진폭, 위상 및 흐름장이 실측값과 비교해서 재현성있게 시뮬레이션 되었다. $M_2,\;M_2+S_2$ 그리고 반일주조에 일주조 성분($K_1$과 $O_1$)의 합성에 의한 잔차류 결과는 유속의 변화와 더불어서 일부 지역에서 흐름패턴이 다르게 계산되었다. 하계 탁월풍의 세기가 커지면 양쯔강 하구에서 유출하는 힘과 대륙붕단 경계역에서 북상하는 흐름의 유속이 다소 증가하는 것으로 나타났다. 양쯔강에서 유출한 흐름은 근역에서는 동향성분이 강하게 나타나지만, 곧 황해에서 남하하는 성분에 의해 동쪽으로 충분히 확산하지 못하고 남하하거나 속도가 감소되는 것으로 나타났다. 육상 유입원의 하계 평균 유량(특히, 양쯔강은 약 $50,000\;m^3/s$)과 남풍 3.5 m/s를 고려했을 경우, 26 psu 이하의 저염수가 유입지점에서 약 95 km정도 확장되고, 30 psu 이하의 염분농도선도 약 160 km까지 확장되는 것으로 나타났고, 최대 홍수량인 $116,000\;m^3/s$를 고려했을 경우는 26 psu 이하의 저염수가 river mouth에서 약 150 km정도 확장되고, 30 psu 이하의 염분농도선도 약 300 km까지 확장되는 것으로 예측되었다. 하계 탁월풍에서 풍속이 약 1.5m/s 정도 강해지면, 저염의 확산 폭이 약 10 km정도 증가하는 것으로 나타났고, 외해에 있어서 저염수는 남서풍에 의해서는 남동방향으로 그리고 북서풍에 의해서는 남서방향으로 퍼져나가는 양상을 보였다. 양쯔강에서 유출되는 평균적인 담수량에 의한 관성력과 조류의 힘만으로는 저염수가 제주도까지 도달하는 것은 힘들겠지만, 바람장과 북상하는 난류의 흐름이 합쳐질 때는 충분히 제주도 인근 해역까지 그 영향을 미칠 수 있을 것으로 예측되었다.

• 한국지구과학회지
• /
• 제26권3호
• /
• pp.240-252
• /
• 2005

한반도 주변 해역의 5개 지점(덕적도, 칠발도, 거문도, 거제도, 동해 정점)에서 관측된 기상청의 해양 기상 관측 부이 자료를 이용하여 각 해역에서 바람과 파도의 관계를 분석하였다. 전반적으로는 서해 정점에서는 파도가 바람의 영향을 가장 많이 받고 남해 정점에서는 파도가 바람의 영향을 가장 적게 받으며 동해 정점에서는 그 중간이며 각 정점별 특징은 다음과 같다. 칠발도에서는 풍속이 강한 겨울철의 주 풍향인 북서방향으로 바다가 트여있고 얕은 수심에 의한 여울효과로 가장 높은 파고가 발달하며 풍향과 파향이 다른 정점에 비해서 가장 잘 일치한다. 이에 비해 덕적도는 북서방향이 황해도에 의해 막혀 있기 때문에 취송거리가 제한되어 겨울철에 충분히 발달한 파도가 생기지 않는다. 이러한 취송거리의 제한은 남해 정점에서 더 크다. 북풍이 우세한 남해의 두 정점에서는 북쪽의 육지 때문에 파도의 발달이 제한되어 바람이 강해도 파고는 거의 높아지지 않는다. 남해 정점에서는 어느 방향에서 바람이 불든지 모든 파향의 파가 고르게 유입되며 그 중 우세한 파향은 항상 동중국해에서 유입되는 방향이다. 그 방향은 거문도와 거제도에서 각각 남쪽 방향과 남서 방향이며 이 방향으로는 바람이 약할 때도 파도가 유입된다. 동해 정점에서는 수심이 깊어 파도가 크게 발달하지만 풍향과 파향이 일치하지 않는 경우가 많아 파고의 발달이 칠발도에서 보다는 낮다. 이와 같이 풍속과 더불어 풍향이 파랑발달에 중요한 이유는 풍향에 의해 취송거리가 결정되기 때문이다. 덕적도와 칠발도에서 풍향이 변하지 않고 오래 지속되는 경우를 보면 파향이 풍향과 일치하며 파고는 최대풍속 후에 최대파고가 나타나는 반응시간이 길수록 커지는 것을 볼 수 있다. 그러나 풍향과 파향이 일치하지 않는 동해 정점의 경우에서는 풍속이 크고 반응시간이 길어도 파고가 서해 정점에서와 같이 많이 높아지지는 않는다. 이상의 결과는 풍속이 클수록, 취송거리가 길수록, 지속시간이 길수록 파고가 크게 발달하는 일반적인 경향과 더불어 각 정점별로는 육지와 바다의 방향, 해저지형, 주변해역의 규모 등의 환경조건에 의해 바람에 의한 파도의 발달율이 달라지는 것을 보여준다.