• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.68 no.4
• /
• pp.236-245
• /
• 2023

We investigated the basic vegetative phase (BVP), photoperiod-sensitivity (PS), and thermo-sensitivity (TS) of 40 rice varieties to characterize their heading ecology that is adaptable to North Korean rice production areas. The ranges were 12 - 43 days for BVP, 0 - 74 days for PS, and 15 - 33 days for TS, depending on the variety. The number of days from transplanting to the heading stage (DTH) was significantly correlated with PS in the 13 major rice production regions where all 40 varieties (including early-, middle-, and mid-late-maturing varieties) were tested. DTH was significantly correlated with BVP and TS but not with PS in the 10 low-temperature regions where only 28 early-maturing varieties were tested. The heading ecology of the adaptable varieties for each region could be characterized by an exponential equation between the BVP and PS of varieties that headed at the border of the safe marginal heading date (SMHD) for each of the seven regional environments (Kaesong, Haeju, Yongyon, Singye, Sariwon, Nampo, and Pyongyang). A PS of 25 - 30 days or less was an additional adaptive trait in the Sariwon and Pyongyang environments. The varieties that reached the heading stage not later than the SMHD in six regional environments (Anju, Kusong, Sinuiju, Changjon, Wonsan, and Supung) and those that reached the heading stage not later than the late marginal heading date (LMHD) in four regional environments (Hamhung, Pyonggang, Huichon, and Kanggye) had both a PS of 26 days or less and a BVP of 25 - 28 days or less. In the Yangdok, Sinpo, and Chunggang environments, varieties that reached the heading stage not later than the LMHD for each region had a BVP of 15 - 20 days or less. The results suggested that a shortened BVP trait should be introduced to existing early-maturing rice varieties to reduce the duration of growth period to reach the heading stage.

• Economic and Environmental Geology
• /
• v.48 no.1
• /
• pp.51-63
• /
• 2015

I produced a secular variation model of geomagnetic field by using the magnetic component data from four geomagnetic observatories located in Northeast Asia during the years between 1997 and 2011. The Earth's magnetic field varies with time and location due to the dynamics of fluid outer core and the magnetic observatories on the surface measure in time series. To adequately represent the magnetic field or secular variations of the Earth, a spatio-temporal model is required. In making a global model, satellite observations as well as limited observatory data are necessary to cover the regions and time intervals. However, you need a considerable work and time to process a huge amount of the dataset with complicated signal separation procedures. When you update the model, the same amount of chores is demanded. Besides, the global model might be affected by the measurement errors of each observatory that are biased and the processing errors in satellite data so that the accuracy of the model would be degraded. In this study, as considered these problems, I introduced a localized method in modeling secular variation of the Earth's magnetic field over Northeast Asia region. Secular variation data from three Japanese observatories and one Chinese observatory that are all in the INTERMAGNET are implemented in the model valid between 1997 to 2011 with the interval of 6 months. With the resulting model, I compared with the global model called CHAOS-4, which includes the main, secular variation and secular acceleration models between 1997 to 2013 by using the three satellites' databases and INTERMAGNET observatory data. Also, the geomagnetic 'jerk' which is known as a sudden change in the time derivatives of the main field of the Earth, was discussed from the localized secular acceleration coefficients derived from spline models.

• Journal of Navigation and Port Research
• /
• v.28 no.1
• /
• pp.59-67
• /
• 2004

As the environment for international logistics varies according to the globalization in world economy, world-class seaports are struggling for the position as strongholds in their own block. As a new government begins its own era in Korea, they are positively implementing their strategies at the level of government for making the Korean Peninsula the logistics centre in North-eastern Asia, marking the most of its geographic advantage. As one of those strategies, it plans to foster a specific area as an international logistics base camp in Northeast Asia by activating its logistics industry through inducing multinational logistics enterprises. In reality, however, in order for Busan seaport, the late-comer, to induce investment from the world-class multinational companies, a considerably large volume of investment should be given from both central and local governments. Accordingly, the objective of this study is to assess its competitiveness and to suggest an activation plan for BSDFA(Busan Seaport Duty-Free Area), based upon the results of on-the-spot interviews in China and Japan. The survey for the respondent's preference by way of Conjoint Analysis indicated that Investment procedures and limitations get the highest 36.2％ preference, so the most critical strategy to be considered for attracting enterprises into DFA(Duty-Free Area) is to solve the problems related to the investment procedures and limitations. The simulation analysis results for market share showed that UAE has the highest preference and BSDFA the lowest preference among the five countries. However, when the levels of investment procedures and limitations and production costare upgraded, the competitiveness of BSDFA was elevated next to that of UAE among the 5 countries. Thus, in order for BSDFA to obtain competitiveness, it is implied that production cost level as well as investment procedures and limitations level, should be lowered so that it could meet companies' demand.

• Korean Journal of Remote Sensing
• /
• v.20 no.2
• /
• pp.77-89
• /
• 2004

The spatial and temporal variations of aerosol optical depth (AOD) over Northeast Asia regions have special importance in the aerosol research for estimation of aerosol radiative forcing parameters and climate change. Aerosol optical and physical properties (AOD and ${\AA}$ngstrom parameter) have been investigated by using Moderate Resolution Imaging Spectroradiometer (MODIS) and Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) to estimate aerosol characteristics over the study region during 2001. Additionally, aerosol characteristics over the Korean peninsular during Aerosol Characteristic Experiment in Asia (ACE-Asia) Intensive Observation Period (IOP) have been investigated by using satellite observations. The results showed that the daily-observed aerosol data indicate seasonal variations with relatively higher aerosol loading in the spring and very low during the winter. The typical Asian dust case showed higher AOD (>0.7) with lower Angstrom exponent (<0.5) and higher AI (>0.5) that is mainly due to the composition of coarse particles in the springtime. Mean AOD for 2001 at 4 different places showed 0.65$\pm$0.37 at Beijing, 0.31$\pm$0.19 at Gosan, 0.54$\pm$0.26 at Seoul, and 0.38$\pm$0.19 at Kwangju, respectively. An interesting result was found in the present study that polluted aerosol events with small size dominated-aerosol loading around the Korean peninsular are sometimes observed. The origin of these polluted aerosols was thought to East China. Aerosol distribution from satellite images and trajectory results shows the proof of aerosol transport. Therefore, aerosol monitoring using satellite data is very useful.

• Journal of Korea Port Economic Association
• /
• v.32 no.3
• /
• pp.95-108
• /
• 2016

China has recently advocated a national strategy called "One Belt One Road" and transferred to execution to refine it into detailed action plans and has continued to fix the complement. However, the Korean Peninsula, including the North Korea remains could not be included at all in the Chinese development policy and framework in terms of the International Logistics. Currently it is raised between Korea-China rail ferry system again and that is when we need to make effective policy development on international multimodal transport system in Northeast Asia. This paper introduces the K-LB (Korea LandBridge) as its execution plan and conducted a feasibility study on this. K-LB consists of a Korea-Russian train ferry system based in Pohang Yeongil New Port(light-wing) and a Korea-China train ferry system based in Saemangeum New Port(left-wing). These two wings are linked to the existing rail system in Korea. This study is convinced that the K-LB is an effective international logistics system in the current terms and conditions and also demonstrated that it is feasible to introduce th K-LB on the peninsula. More strictly speaking, through a linear programming under objective function that minimize the transport cost quantified prior to demonstrate the feasibility, the available ranges and conditions for the transportation costs that are ensured the effectiveness of the K-LB are presented as results. According to the results, if the transport cost of K-LB is cheaper about 34.5% than that of sea transport such as container transport, the object goods may be transported by K-LB on this route. It means that the K-LB system has a competitive advantage due to more rapid customs clearance as well as omitted loading and unloading procedures over container transportation system. It also noted that the threshold level may not be large. Therefore, K-LB has competitive enough to prove its introduction in the Northeast Asian logistics system.

• Journal of Korea Port Economic Association
• /
• v.24 no.4
• /
• pp.363-384
• /
• 2008

This study aims at improving Korea's competitiveness in port logistics through marketing strategy with integrating the conceptual approach into the empirical one and combining both the oldest military treatise and the newest evaluating model in social science that was applied by the HFP(hierarchical fuzzy process) model enhanced by the KJ method. The empirical results of this study show Busan in the middle among subject ports. At present, Korea plays a reciprocal role in the port market in East Asia, but in the medium- and long-term, Korea's ports will vie together with most major ports in the East Asian region. A descriptive investigation shows that Korea's developing tasks in port logistics must be considered in the context of the direction for developing port policies, the necessity of expanding port facilities in the capital region, securing the sufficient traffic volume through the establishment of the hinterland linking system and its positive utilization, and reforming the direction for developing the global logistics through increased port competitiveness. In the short- and medium-term, Korea must use the opportunity factor of 'Growth and open door policy of China' as a geoeconomic advantage and to utilize Korea's ports as a gate to Chinese foreign trade. With the rise of China's economy, China also plays a significant role in both port and airport markets. Hence, the linking system between the two must be established to meet the expanding traffic volume, especially in the capital area. Moreover, it is necessary for Korea to secure port logistics through the establishment of the hinterland linking system and its positive utilization. The great accomplishment of this paper is to present strategies to increase Korea's port competitiveness in the rapidly changing environments of world logistics with the focus on both the oldest military strategic treatise and the newest empirical method in social science. In order to reinforce this study, it needs further compensative research because the evaluation structure could be subdivided with more extensive and precise criteria.

• Korean Journal of Heritage: History & Science
• /
• v.43 no.1
• /
• pp.260-279
• /
• 2010

The analysis on bibliography and field investigation of Callipogon relictus Semenov, 1898 (Korean natural monument number 218) shows that the size varies from country to country, and Korean specimens, for which male is 85~120mm and female is 65~85mm, are found to be the largest. The average diameter and length of egg are 2.60mm and 6.72mm respectively. The larva has milky color and is about 100~150mm in length. The pupa is nearly 70~110mm. An adult generally appears from June to September in Korea in the broadleaf forest of lowland, whereas it appears from June to July in China. It is known that the pupa largely feed on the old tree trunk of Carpinus laxiflora (Siebold & Zucc.) blume in Korea, but no such data have been reported in China and Russia, showing differences in host plants. While the larva period is not exactly known in Korea, it is reported to be two years in China. It appears that the species inhabits in very limited regions of approximately between geographical latitude $37.5^{\circ}{\sim}47.8^{\circ}$ and longitude $126^{\circ}{\sim}140^{\circ}$ including Korea, China and Russia. To conserve the long-horned beetle in Korea, this research drew out following some conclusions through analyzing the references and field survey data. First, it need to perform precise survey on the natural environment of occurring and collected area or place including host plant kinds, temperate, humidity, latitude, longitude etc. Second, habitat region must be designated as a restricted development area, and it need to exclude or reduce the damage factors to prosper reproduction of the species. Third, it is necessary to keep loosing cautiously artificial breeding individuals in the reported sites, not disturbing scope of natural populations. Fourth, it needs to educate or publicize many people importance and value of this species through many methods.

• The Korean Journal of Air & Space Law and Policy
• /
• v.32 no.1
• /
• pp.287-325
• /
• 2017

Considering the development of aerospace, military science and technology since the 20th century, the sky is very important for the nation's existence and prosperity. The proverb "Whosoever commands the space commands the world itself!" emphasizes the need for the command of the air. This essay is the first study on the status of airspace after reunification. First, the territorial airspace is over the territory and territorial sea, and its horizontal extent is determined by the territorial boundary lines. Acceptance of the present order is most reasonable, rather than attempting to reconfigure through historical truths about border issues, and it could be supported by neighboring countries in the reunification period. For peace in Northeast Asia, the reunified Korea needs to respect the existing border agreement between North Korea and China or Russia. However, the North Korean straight baselines established in the East Sea and the Yellow Sea should be discarded because they are not available under United Nations Convention on the Law of the Sea. It is desirable for the reunified Korea to redefine the straight baselines that comply with international law and determine the territorial waters up to and including the 12-nautical mile outside it. Second, the Flight Information Region (hereinafter "FIR") is a region defined by the International Civil Aviation Organization (hereinafter "ICAO") in order to provide information necessary for the safe and efficient flight of aircraft and the search and rescue of aircraft. At present, Korea is divided into Incheon FIR which is under the jurisdiction of South Korea and Pyongyang FIR which is under the jurisdiction of North Korea. If North Korea can not temporarily exercise control of Pyongyang FIR due to a sudden change of circumstances, it is desirable for South Korea to exercise control of Pyongyang FIR, and if it is unavoidable, ICAO should temporarily exercise it. In reunified Korea, it is desirable to abolish Pyongyang FIR and integrate it into Incheon FIR with the approval of ICAO, considering systematic management and control of FIR, establishment of route, and efficiency of management. Third, the Air Defense Identification Zone (hereinafter "ADIZ") is a zone that requires easy identification, positioning, and control of aircraft for national security purposes, and is set up unilaterally by the country concerned. The US unilaterally established the Korea Air Defense Identification Area (KADIZ) by the Declaration of Commitment on March 22, 1951. The Ministry of Defense proclaimed a new KADIZ which extended to the area including IEODO on December 13, 2013. At present, North Korea's military warning zone is set only at maritime boundaries such as the East Sea and the Yellow Sea. But in view of its lack of function as ADIZ in relations with China and Russia, the reunified Korea has no obligation to succeed it. Since the depth of the Korean peninsula is short, it is necessary to set ADIZ boundary on the outskirts of the territorial airspace to achieve the original purpose of ADIZ. Therefore, KADIZ of the reunified Korea should be newly established by the boundary line that coincides with the Incheon FIR of the reunified Korea. However, if there is no buffer zone overlapping with or adjacent to the ADIZs of neighboring countries, military tensions may rise. Therefore, through bilateral negotiations for peace in Northeast Asia, a buffer zone is established between adjacent ADIZs.

• Korean Journal of Breeding Science
• /
• v.42 no.6
• /
• pp.615-622
• /
• 2010

A new rice cultivar, 'Joami', was developed by the rice breeding team of Sangju Substation, National Institute of Crop Science (NICS), Rural Development Administration. It was selected by a bulk and pedigree methods from a cross-combination among 'Sambaegbyeo', 'Yukara', and 'Tonggae112'. A promising line of YR20557-1-1-3-B-3 was designated as 'Sangju 36' in 2006. Local adaptability test of 'Sangju 36' was conducted at ten sites throughout the Korean peninsula during three years from 2006 to 2008. 'Sangju 36', thereafter, was registered as 'Joami' in 2008. The cultivar headed on July 30 in the test of local adaptability. Endosperm of 'Joami' is translucent with clear chalkiness and has 5.4% higher head rice ratio than that of 'Odaebyeo'. The yield potential of 'Joami' in milled rice is about 5.40 MT/ha under ordinary fertilizer level of local adaptability test, which was 6% higher than that of 'Odaebyeo'. In an alpine area of Korea, the rice variety needs a cold tolerance and a resistance to blast disease. 'Joami' showed a tolerance reaction at Chuncheon cold tolerance screening nursery and exhibited resistance reaction to blast disease in nation-wide disease screening nursery. Therefore, 'Joami' would be well adaptable to mid-mountainous area at central and southern part of Korean peninsula.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.2
• /
• pp.22-37
• /
• 2021

The wind chime is a longstanding Jangeomgu (majestic article) found in Korea, China, and Japan. However, basic research on wind chimes is currently inadequate as it is difficult to estimate the time of production, and there are few relics. Therefore, this research morphologically classifies the eight bronze wind chimes decorating the baldachin of the Stone Standing Maitreya Bodhisattva of Gwanchoksa Temple, Nonsan. Based on this, the manufacturing techniques and production period are scientifically demonstrated. The synthesis of the research results reveals that the structure and characteristics of the wind chimes of the Stone Standing Maitreya Bodhisattva of Gwanchoksa Temple, Nonsan differ depending on their location on the baldachin. The four large-sized wind chimes on the lower-baldachin were manufactured by casting a Cu-Sn-Pb alloy, and they are estimated to have been made during the early period of Goryeo. The two medium-sized wind chimes of the upper-baldachin's northern direction were manufactured through forging a Cu-Sn or Cu-Sn-Pb alloy, and they appear to have a similar structure to the cylindrical wind chimes appearing during the latter period of Goryeo and the Joseon period. The two small-sized wind chimes of the upper-baldachin's southern direction were manufactured by casting a Cu-Sn-Pb alloy containing Zn, and based on the chemical composition of the alloy and the shape of the clapper, they are estimated to have been manufactured during the latter period of Joseon. Through the observation of microstructures and a chemical composition analysis, it is demonstrated that two wind chimes of the lowerbaldachin were manufactured by casting and slow cooling the alloy with an alloy ratio of Cu:Sn:Pb≒80:15:5. In addition, it is estimated that the wind chimes of the upper-baldachin's northeast direction were manufactured by forging an alloy of Cu-Sn with a similar alloy ratio to that of forged high tin bronze. The results of a comparative analysis of prior research on domestic wind chimes confirm that two wind chimes of the lower-baldachin have a similar composition ratio to the wind chime excavated from Wolnamsaji in Gangjin, containing an amount of tin that corresponds with ancient records. Having a similar alloy ratio to forged high tin bronze, the wind chimes of the upper-baldachin's northeast direction are the only instances among all of the wind chimes that have been examined to date that were manufactured using this forging method. The purpose of this research is to collect baseline data to verify and classify the manufacturing period of wind chimes according to their morphological characteristics based on scientific evidence. It is hoped that this data can be utilized for the restoration and conservation processes of the wind chimes of the Stone Standing Maitreya Bodhisattva of Gwanchoksa Temple, Nonsan.