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A Study on Illegal Transfer Paths of North Korea’s Strategic Items
Han-Sol Ko,Su-Hyeon Kim 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1
In the previous study, the types of North Korea’s strategic items, foreign trading partners, and export items were investigated. From North Korea’s typical trade paths, it is possible to predict the paths through which North Korea’s strategic items are illegally exported upon denuclearization. Trading partners of North Korea are the potential importing countries or end-users of strategic items, which can be disguised or concealed as if it is general export items during typical export procedures. So, in this study, transfer paths of North Korea’s export items are examined by utilizing KOTRA statistics, including item type HS code and its total price. Also, AnyLogic, a comprehensive simulation modeling tool, the simulation will be conducted to identify the paths for illegal transfer and calculate the time required. The information on North Korea’s trading partners and items is used for establishing export scenarios in which strategic items are transferred to other countries through North Korea’s ports, airports, railroads, and roads. To be specific, China, Russia, and South Korea, countries that share a border with North Korea, export items transported only by land; the items will arrive first in the referred three countries. Since the types of items, North Korea transacts with each country are different, the total amount and frequency of transactions are different; the probability of strategic items being included in general export items and transferred during customs clearance also varies. Even if it does not border North Korea, North Korea can export items through ports to countries adjacent to the coastline, and North Korea can even export items to any country by airspace even if it is not adjacent to the coastline. So, all publicly open ports, airports, railways, and roads are surveyed. Their geographic information, such as EPSG 4326 and EPSG 3857 coordinate system, are applied to confirm and visualize valid export paths starting from North Korea. In conclusion, effective export paths in North Korea are identified based on North Korea’s each major transportation hub by using AnyLogic simulation. It is possible to predict the paths through which North Korea’s strategic items will be transferred by combining information on major export items and countries that North Korea mainly transacts with.
A Review of North Korea’s Major Trading Partners and Items
Han-Sol Ko,Su-Hyeon Kim 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1
Investigating major trading partners and items with North Korea is informative in terms that it can predict the path through which North Korea’s strategic items will transfer to non-nuclear-weapon states when North Korea denuclearizes. By analyzing North Korea’s trading partners and the items, it is possible to identify the relevant countries through which items arrive from the first importing country to the end-user in the process of exporting items and to predict the way how North Korea disguise or conceal their strategic items among general items during normal export procedures. As of 2020, North Korea’s major trading partners are China, Russia, Vietnam, India, Nigeria, and Switzerland. Compared to 2019, Mozambique, Tanzania, Ghana, and Thailand entered the top 10, while Brazil, Bangladesh, Pakistan, and South Africa pushed out of the top 10. North Korea’s trade dependence on China accounts for 88.2%, making it the largest trading partner for years, and it shows that North Korea is mainly conducting trade with Asian and African countries. North Korea’s most important export items are mineral products (HS 25-27) and steel & metal products (HS 72-83) and the most significant import items are mineral products (HS 25-27) and oils & fats & prepared foods (HS 15-24). In 2017, due to UN Security Council sanctions for North Korea’s international ballistic missile (ICBM) test-fire, North Korea’s exports from 3 billion dollars fell by 90% to less than 300 million dollars. This is the result of most of North Korea’s major export items included in the export ban, and changes have occurred in its export items. In 2020, export fell to less than 100 million dollars due to border lockdown measures to prevent the spread of COVID-19, which also affected the change of North Korea’s major export items. Although North Korea does not officially publish its foreign trade statistics, in order to review North Korea’s trade information, KOTRA statistics are utilized. KOTRA statistics provide only two digits of HS code number, so it is challenging to identify detailed item classification. Moreover, these statistics are based on the export amount, so it is difficult to determine the exact quantity of export items. It is expected that information on North Korean trading partners and items will be used to predict potential transferable export methods of North Korea’s strategic items when North Korea denuclearizes.
Analysis of North Korea’s Foreign Trade and Logistics Infrastructure
Han-sol Ko,Chan-suh Lee,Seung-hyo Yang 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2
From 1970 to 1990, North Korea’s trade mainly carried out maritime trade through ports for countries around the world. This trend is due to UN sanctions against North Korea, and after the third nuclear test in 2016, North Korea gradually became isolated from the outside world as it expanded to include maritime sanctions in the form of comprehensive sanctions targeting an unspecified majority of North Korea. The logistics structure of North Korea is due to the logistics infrastructure left during the Japanese colonial period in the 1950s and the political structure of the country, with railroads being the main source of logistics and passenger transportation, and roads being secondary. North Korea faced rapid deterioration and lack of facilities after 1990 due to the lack of investment in facilities and improvement of the operating system despite the advanced logistics infrastructure and operating system compared to the South. In particular, the power shortage in North Korea hindered the operation of the railroad and accelerated the aging of the railroad facilities, which has continued to this day. In the 2010s, 96% of cargo transportation in North Korea’s logistics infrastructure depended on railroads and roads, and ports that were developed until the 1980s have deteriorated with little investment since the economic crisis of the 1990s. Although some ports have been developed since 2010, North Korea’s east and west coasts are separated and there is no function of shipping to connect ports, so it did not have a significant impact on enhancing the nation’s port capacity. As North Korea’s trade dependence on China has increased, North Korea has largely relied on land transport, except for some cargoes that are advantageous for marine transport, such as coal. This structure again leads to a decrease in investment in ports, and the current vicious cycle of causing problems with North Korean port facilities is repeated. In this study, North Korea’s land and marine trade logistics system such as railway, road, and shipping and the trend of foreign trade due to sanctions against North Korea were analyzed. Through this analysis, it is planned to be used as a basis for developing the routes and scenarios through which major nuclear items can be transferred in the event of denuclearization of North Korea in the future.
Han Sol,Song Sung Wook,Hong Hansol,김우정,강영준,Park Chang Bae,Kang Jeong Ho,Bu Ji Hwan,이성근,Ko Seo Young,이수훈,Kang Chul-Hoo 대한응급의학회 2023 Clinical and Experimental Emergency Medicine Vol.10 No.2
Objective: This study investigated the hospital diagnoses and characteristics of uncooperative prehospital patients suspected of acute stroke who could not undergo a prehospital stroke screening test (PHSST). Methods: This retrospective observational study was conducted at a single academic hospital with a regional stroke center. We analyzed three scenario-based prehospital stroke screening performances using the final hospital diagnoses: (1) a conservative approach only in patients who underwent the PHSST, (2) a real-world approach that considered all uncooperative patients as screening positive, and (3) a contrapositive approach that all uncooperative patients were considered as negative. Results: Of the 2,836 emergency medical services (EMS)-transported adult patients who met the prehospital criteria for suspicion of acute stroke, 486 (17.1%) were uncooperative, and 570 (20.1%) had a confirmed final diagnosis of acute stroke. The diagnosis in the uncooperative group did not differ from that in the cooperative group (22.0% vs. 19.7%, P=0.246). The diagnostic performances of the PHSST in the conservative approach were as follows: 79.5% sensitivity (95% confidence interval [CI], 75.5%–83.1%), 90.2% specificity (95% CI, 88.8%–91.6%), and 0.849 area under the receiver operating characteristic curve (AUC; 95% CI, 0.829–0.868). The sensitivity and specificity were 83.3% (95% CI, 80.0%–86.3%) and 75.2% (95% CI, 73.3%–76.9%), respectively, in the real-world approach and 64.6% (95% CI, 60.5%–68.5%) and 91.9% (95% CI, 90.7%–93.0%), respectively, in the contrapositive approach. No significant difference was evident in the AUC between the real-world approach and the contrapositive approach (0.792 [95% CI, 0.775–0.810] vs. 0.782 [95% CI, 0.762–0.803], P>0.05). Conclusion: We found overestimation (false positive) and underestimation (false negative) in the uncooperative group depending on the scenario-based EMS stroke screening policy for uncooperative prehospital patients suspected of acute stroke.
Sol Han,Hong Jin Kim,Myung Ki Hong,Byoung Ho Kwon,Kuntack Lee,Youngsun Ko 대한금속·재료학회 2013 ELECTRONIC MATERIALS LETTERS Vol.9 No.2
In this paper, effect of ultrafine ceria (UFC) particle of which size is as small as 20 nm on CMP performance was investigated. Compared to conventionally used 100 nm abrasive particle which is made by calcination process, almost 80% scratch reduction was obtained by using UFC. However, a UFC slurry showed unstable material removal rate behavior from less than 200 Å/min to over 2000 Å/min, depending on polishing pad surface characteristics. As pad surface roughness increases, oxide removal rate using UFC drops abruptly to less than 200 Å/min. In order to use UFC for scratch reduction, the pad surface roughness optimization is necessary to avoid a sudden drop in the removal rate. This study gives a possible boundary for pad surface roughness for UFC application for CMP.
Lee, Han Sol,Choi, Kyunghee,Kim, Jin Sung,Yu, Sanghyuck,Ko, Kyeong Rok,Im, Seongil American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.18
<P>We report the fabrication of hybrid PN junction diode and complementary (CMOS) inverters, where 2D p-type MoTe2 and n-type thin film InGaZnO (IGZO) are coupled for each device process. IGZO thin film was initially patterned by conventional photolithography either for n-type material in a PN diode or for n-channel of top-gate field-effect transistors (FET) in CMOS inverter. The hybrid PN junction diode shows a good ideality factor of 1.57 and quite a high ON/OFF rectification ratio of similar to 3 x 10(4). Under photons, our hybrid PN diode appeared somewhat stable only responding to high-energy photons of blue and ultraviolet. Our 2D nanosheet oxide film hybrid CMOS inverter exhibits voltage gains as high as similar to 40 at 5 V, low power consumption less than around a few nW at 1 V, and similar to 200 mu s switching dynamics.</P>