Aplicación del proceso de jerarquía analítica (AHP) en la selección de tecnología logística

El transporte terrestre es una de las modalidades más utilizadas en el mundo para transportar mercaderías, luego del transporte marítimo, moviéndose anualmente más de 6.000 Tn/km (Banco Mundial, 2019). Por lo tanto, es un motor fundamental en la economía de los países y esto lleva a que exista un gran interés por parte de las empresas transportistas y de los clientes para encontrar formas de optimizar este proceso. En la composición de los costos empresariales, se calcula que el costo total de distribución representa un 7,65%, del cual el costo de transporte es el de mayor incidencia con un 3,34% (Ballou, 2004), por lo tanto, su análisis y optimización son fundamentales para lograr competitividad. En la empresa logística bajo estudio, se cuenta con personal encargado para la carga y selección de la mejor ubicación de las mercaderías dentro de semirremolques, quienes utilizan su experiencia y métodos empíricos para hacer el trabajo. Para esta organización en particular, no está establecido el uso de alguna plataforma digital para la gestión del llenado eficiente de los vehículos de carga. En este trabajo, se abordó, el problema de selección de un sistema computacional logístico para la gestión de la carga y su ubicación eficiente dentro de semirremolques de una empresa paraguaya, importadora y exportadora de mercaderías. Dado que, para la elección del mejor software, especializado para la carga eficiente de móviles con mercaderías, se debe tener en cuenta múltiples criterios, se presenta una propuesta de selección basada en el Proceso de Jerarquía Analítica (Analytical Hierarchy Process, AHP), para comparar los sistemas computacionales para la logística de carga y ubicación de mercaderías. De esta manera, se pudo definir una ponderación de los criterios a evaluar en términos de pesos, de acuerdo con su nivel de importancia, gerencial y operacional, para finalmente tener una elección objetiva y que cumpla con los requerimientos predefinidos. Los sistemas computacionales disponibles son Easy Cargo, Searates, Goodloading y Logen Solutions. Mientras que los criterios analizados fueron funcionalidad, practicidad, precio, idiomas de interfaz, y conectividad con otras plataformas, con ese orden para el valor de las ponderaciones de mayor a menor. Con estas variables, se realizó la jerarquización, construyendo matrices de comparación pareadas para evaluar cada alternativa respecto de cada criterio, como así también, criterio versus criterio. Se realizó un test de consistencia para cada matriz pareada; por un lado, para matrices de comparación entre alternativas criterio por criterio, y para la matriz de comparación criterio versus criterio. Al efectuar el test de consistencia de cada matriz pareada, se determinó que cada Razón de Consistencia (RC) para las matrices de comparación entre alternativas fue menor a 0.09 (9%), cota superior permitida para matrices de orden 4x4 según Aznar y Guijarro (2012). En cuanto a la RC de la matriz de comparación criterio versus criterio, no se sobrepasó la cota superior de 0,1(10%) para matrices de orden 5x5. Se concluye que la metodología propuesta es aceptable, pues permitió la jerarquización y la selección del mejor sistema computacional logístico para carga y ubicación de mercaderías, de acuerdo con los criterios tomados en cuenta. De acuerdo con los resultados de la ponderación final para la elección el mejor sistema es Logen Solutions (0.38). Se propone como trabajo futuro, incrementar el número de opciones de sistemas computacionales, y ahondar en más criterios como costo de mantenimiento, tiempo de capacitación, tiempo de implementación, entre otros.Sociedad Argentina de Informática e Investigación Operativ

Diseño de un modelo de optimización para la disposición final de envases de vidrios en los barrios de la ciudad de Asunción - Paraguay

Una gestión integral de residuos sólidos eficiente y sostenible en términos ambientales, es aquella que permite que llegue como máximo un 20% de los residuos totales a vertederos o rellenos sanitarios como destino final (Abbate, 2011). Para el 2017, el Ministerio del Ambiente y Desarrollo Sostenible estimó que un 20% de los 254 municipios del Paraguay cuentan con programas de reciclajes (MADES, 2020), utilizando precarios procesos de separación de materiales en vertederos municipales y clandestinos, con trabajadores informales. Actualmente, existe una brecha enorme entre los negocios realizados por los grupos de recicladores en el principal relleno sanitario de la capital, Cateura, y el volumen potencial de negocios que podría realizarse en el mismo lugar, desde una perspectiva distinta. Salvo casos aislados, como el programa Recicla 2.0 de Asunción para potenciar el reciclaje en barrios, se resalta que la separación y recolección de residuos tiene poca participación en las agendas medioambientales, y en este trabajo se da foco a uno de los residuos menos considerados: el vidrio (MADES, 2020). En este sentido, con el fin de fortalecer la gestión de residuos en los municipios, se plantea la posibilidad de estructurar la disposición temporal y final del vidrio, mediante un modelo de programación mixta entera lineal que permita ubicar puntos de captación de residuos (puntos verdes) en los barrios de la ciudad de Asunción, y también localizar centros de acopio con posibilidades de triturado y/o acondicionamiento de dicho residuo. Además, se desea asignar y rutear vehículos para la recolección desde los puntos verdes hasta los centros de acopio, y programar la distribución de materiales procesados hasta los clientes finales. Conjuntamente, se analizarán estrategias económicamente viables para determinar la rentabilidad de la inversión en una unidad de negocio verde, proveedora de clientes que utilicen productos reciclados o reutilizados como insumo industrial o comercial. Finalmente, es axiomático que, si se clasifican los residuos de las viviendas en reciclables y no reciclables, el mercado del reciclaje se incrementará considerablemente con el consecuente impacto social, económico y ambiental positivo que ello conlleva, además de la mejora ambiental que implicaría no enterrar un gran porcentaje de materiales que hoy tienen valor comercial (Abbate, 2011); razón por la que se emprende esta investigación.Sociedad Argentina de Informática e Investigación Operativ

Selección de establecimientos escolares en el departamento de Caazapá aplicando programación matemática

Las decisiones en infraestructura educativa en el departamento de Caazapá, como en otras regiones del Paraguay, generan algunos inconvenientes. En particular, la distribución de alumnos respecto a los establecimientos escolares presenta cierta inconsistencia, esto se ve reflejado en sobrecostos por reparación o por mantener aulas/escuelas abiertas. Actualmente, existen 469 escuelas en este departamento, y en promedio se tiene 83 alumnos por escuela. Igualmente, se debe considerar que el 66% de las escuelas tienen menos de 25 alumnos, y se puede inferir que existe una subutilización de la infraestructura y de los costos operativos asociados. Un dato no menor, es que el 1% de las escuelas tiene en promedio más de 49 estudiantes por aula, muy por arriba del promedio en todo el departamento. El diseño de la red educativa es ineficiente, con una concentración de escuelas que excede las necesidades en determinadas zonas y es deficitaria en otras; esto tiene como consecuencia problemas de gestión de recursos y altos costos de inversión para mejorar y mantener las escuelas en distritos que no cuentan con el presupuesto suficiente. Es imperativa la aplicación de estrategias que estén orientadas a la optimización de los recursos disponibles. En este estudio, se identificó un modelo de programación lineal entera mixta (PLEM) existen-te en la literatura, para seleccionar establecimientos escolares a fin de minimizar los costos operativos, de inversión en infraestructura y de transporte. Se combinaron técnicas de investigación operativa con sistemas de información geográfica para analizar el problema e interpretar los resultados. Los resultados muestran oportunidades de mejora en el diseño de la red educativa en los 11 distritos del departamento de Caazapá, y es posible reducir los costos de inversión al consolidar la demanda en menos establecimientos de los que ya existen actualmente. En la selección y distribución de establecimientos escolares, propuesta como solución, se reduce al 50% el número de escuelas, disminuyendo también los costos de inversión y costos operativos. Por otra parte, será necesario incurrir en costos de transporte que representarán el 7% de los costos. Finalmente, con esta propuesta, se reduce el costo estimado para el diseño de la red de infraestructura del sistema educativo en el departamento de Caazapá en un 24% con respecto al costo actual.Sociedad Argentina de Informática e Investigación Operativ

Introduction STATE OF THE CLIMATE IN 2022

Abstract —J. BLUNDEN, T. BOYER, AND E. BARTOW-GILLIES Earth’s global climate system is vast, complex, and intricately interrelated. Many areas are influenced by global-scale phenomena, including the “triple dip” La Niña conditions that prevailed in the eastern Pacific Ocean nearly continuously from mid-2020 through all of 2022; by regional phenomena such as the positive winter and summer North Atlantic Oscillation that impacted weather in parts the Northern Hemisphere and the negative Indian Ocean dipole that impacted weather in parts of the Southern Hemisphere; and by more localized systems such as high-pressure heat domes that caused extreme heat in different areas of the world. Underlying all these natural short-term variabilities are long-term climate trends due to continuous increases since the beginning of the Industrial Revolution in the atmospheric concentrations of Earth’s major greenhouse gases. In 2022, the annual global average carbon dioxide concentration in the atmosphere rose to 417.1±0.1 ppm, which is 50% greater than the pre-industrial level. Global mean tropospheric methane abundance was 165% higher than its pre-industrial level, and nitrous oxide was 24% higher. All three gases set new record-high atmospheric concentration levels in 2022. Sea-surface temperature patterns in the tropical Pacific characteristic of La Niña and attendant atmospheric patterns tend to mitigate atmospheric heat gain at the global scale, but the annual global surface temperature across land and oceans was still among the six highest in records dating as far back as the mid-1800s. It was the warmest La Niña year on record. Many areas observed record or near-record heat. Europe as a whole observed its second-warmest year on record, with sixteen individual countries observing record warmth at the national scale. Records were shattered across the continent during the summer months as heatwaves plagued the region. On 18 July, 104 stations in France broke their all-time records. One day later, England recorded a temperature of 40°C for the first time ever. China experienced its second-warmest year and warmest summer on record. In the Southern Hemisphere, the average temperature across New Zealand reached a record high for the second year in a row. While Australia’s annual temperature was slightly below the 1991–2020 average, Onslow Airport in Western Australia reached 50.7°C on 13 January, equaling Australia's highest temperature on record. While fewer in number and locations than record-high temperatures, record cold was also observed during the year. Southern Africa had its coldest August on record, with minimum temperatures as much as 5°C below normal over Angola, western Zambia, and northern Namibia. Cold outbreaks in the first half of December led to many record-low daily minimum temperature records in eastern Australia. The effects of rising temperatures and extreme heat were apparent across the Northern Hemisphere, where snow-cover extent by June 2022 was the third smallest in the 56-year record, and the seasonal duration of lake ice cover was the fourth shortest since 1980. More frequent and intense heatwaves contributed to the second-greatest average mass balance loss for Alpine glaciers around the world since the start of the record in 1970. Glaciers in the Swiss Alps lost a record 6% of their volume. In South America, the combination of drought and heat left many central Andean glaciers snow free by mid-summer in early 2022; glacial ice has a much lower albedo than snow, leading to accelerated heating of the glacier. Across the global cryosphere, permafrost temperatures continued to reach record highs at many high-latitude and mountain locations. In the high northern latitudes, the annual surface-air temperature across the Arctic was the fifth highest in the 123-year record. The seasonal Arctic minimum sea-ice extent, typically reached in September, was the 11th-smallest in the 43-year record; however, the amount of multiyear ice—ice that survives at least one summer melt season—remaining in the Arctic continued to decline. Since 2012, the Arctic has been nearly devoid of ice more than four years old. In Antarctica, an unusually large amount of snow and ice fell over the continent in 2022 due to several landfalling atmospheric rivers, which contributed to the highest annual surface mass balance, 15% to 16% above the 1991–2020 normal, since the start of two reanalyses records dating to 1980. It was the second-warmest year on record for all five of the long-term staffed weather stations on the Antarctic Peninsula. In East Antarctica, a heatwave event led to a new all-time record-high temperature of −9.4°C—44°C above the March average—on 18 March at Dome C. This was followed by the collapse of the critically unstable Conger Ice Shelf. More than 100 daily low sea-ice extent and sea-ice area records were set in 2022, including two new all-time annual record lows in net sea-ice extent and area in February. Across the world’s oceans, global mean sea level was record high for the 11th consecutive year, reaching 101.2 mm above the 1993 average when satellite altimetry measurements began, an increase of 3.3±0.7 over 2021. Globally-averaged ocean heat content was also record high in 2022, while the global sea-surface temperature was the sixth highest on record, equal with 2018. Approximately 58% of the ocean surface experienced at least one marine heatwave in 2022. In the Bay of Plenty, New Zealand’s longest continuous marine heatwave was recorded. A total of 85 named tropical storms were observed during the Northern and Southern Hemisphere storm seasons, close to the 1991–2020 average of 87. There were three Category 5 tropical cyclones across the globe—two in the western North Pacific and one in the North Atlantic. This was the fewest Category 5 storms globally since 2017. Globally, the accumulated cyclone energy was the lowest since reliable records began in 1981. Regardless, some storms caused massive damage. In the North Atlantic, Hurricane Fiona became the most intense and most destructive tropical or post-tropical cyclone in Atlantic Canada’s history, while major Hurricane Ian killed more than 100 people and became the third costliest disaster in the United States, causing damage estimated at $113 billion U.S. dollars. In the South Indian Ocean, Tropical Cyclone Batsirai dropped 2044 mm of rain at Commerson Crater in Réunion. The storm also impacted Madagascar, where 121 fatalities were reported. As is typical, some areas around the world were notably dry in 2022 and some were notably wet. In August, record high areas of land across the globe (6.2%) were experiencing extreme drought. Overall, 29% of land experienced moderate or worse categories of drought during the year. The largest drought footprint in the contiguous United States since 2012 (63%) was observed in late October. The record-breaking megadrought of central Chile continued in its 13th consecutive year, and 80-year record-low river levels in northern Argentina and Paraguay disrupted fluvial transport. In China, the Yangtze River reached record-low values. Much of equatorial eastern Africa had five consecutive below-normal rainy seasons by the end of 2022, with some areas receiving record-low precipitation totals for the year. This ongoing 2.5-year drought is the most extensive and persistent drought event in decades, and led to crop failure, millions of livestock deaths, water scarcity, and inflated prices for staple food items. In South Asia, Pakistan received around three times its normal volume of monsoon precipitation in August, with some regions receiving up to eight times their expected monthly totals. Resulting floods affected over 30 million people, caused over 1700 fatalities, led to major crop and property losses, and was recorded as one of the world’s costliest natural disasters of all time. Near Rio de Janeiro, Brazil, Petrópolis received 530 mm in 24 hours on 15 February, about 2.5 times the monthly February average, leading to the worst disaster in the city since 1931 with over 230 fatalities. On 14–15 January, the Hunga Tonga-Hunga Ha'apai submarine volcano in the South Pacific erupted multiple times. The injection of water into the atmosphere was unprecedented in both magnitude—far exceeding any previous values in the 17-year satellite record—and altitude as it penetrated into the mesosphere. The amount of water injected into the stratosphere is estimated to be 146±5 Terragrams, or ∼10% of the total amount in the stratosphere. It may take several years for the water plume to dissipate, and it is currently unknown whether this eruption will have any long-term climate effect.</jats:p

State of the climate in 2022: introduction

Earth’s global climate system is vast, complex, and intricately interrelated. Many areas are influenced by global-scale phenomena, including the “triple dip” La Niña conditions that prevailed in the eastern Pacific Ocean nearly continuously from mid-2020 through all of 2022; by regional phenomena such as the positive winter and summer North Atlantic Oscillation that impacted weather in parts the Northern Hemisphere and the negative Indian Ocean dipole that impacted weather in parts of the Southern Hemisphere; and by more localized systems such as high-pressure heat domes that caused extreme heat in different areas of the world. Underlying all these natural short-term variabilities are long-term climate trends due to continuous increases since the beginning of the Industrial Revolution in the atmospheric concentrations of Earth’s major greenhouse gases.In 2022, the annual global average carbon dioxide concentration in the atmosphere rose to 417.1±0.1 ppm, which is 50% greater than the pre-industrial level. Global mean tropospheric methane abundance was 165% higher than its pre-industrial level, and nitrous oxide was 24% higher. All three gases set new record-high atmospheric concentration levels in 2022.Sea-surface temperature patterns in the tropical Pacific characteristic of La Niña and attendant atmospheric patterns tend to mitigate atmospheric heat gain at the global scale, but the annual global surface temperature across land and oceans was still among the six highest in records dating as far back as the mid-1800s. It was the warmest La Niña year on record. Many areas observed record or near-record heat. Europe as a whole observed its second-warmest year on record, with sixteen individual countries observing record warmth at the national scale. Records were shattered across the continent during the summer months as heatwaves plagued the region. On 18 July, 104 stations in France broke their all-time records. One day later, England recorded a temperature of 40°C for the first time ever. China experienced its second-warmest year and warmest summer on record. In the Southern Hemisphere, the average temperature across New Zealand reached a record high for the second year in a row. While Australia’s annual temperature was slightly below the 1991–2020 average, Onslow Airport in Western Australia reached 50.7°C on 13 January, equaling Australia's highest temperature on record.While fewer in number and locations than record-high temperatures, record cold was also observed during the year. Southern Africa had its coldest August on record, with minimum temperatures as much as 5°C below normal over Angola, western Zambia, and northern Namibia. Cold outbreaks in the first half of December led to many record-low daily minimum temperature records in eastern Australia.The effects of rising temperatures and extreme heat were apparent across the Northern Hemisphere, where snow-cover extent by June 2022 was the third smallest in the 56-year record, and the seasonal duration of lake ice cover was the fourth shortest since 1980. More frequent and intense heatwaves contributed to the second-greatest average mass balance loss for Alpine glaciers around the world since the start of the record in 1970. Glaciers in the Swiss Alps lost a record 6% of their volume. In South America, the combination of drought and heat left many central Andean glaciers snow free by mid-summer in early 2022; glacial ice has a much lower albedo than snow, leading to accelerated heating of the glacier. Across the global cryosphere, permafrost temperatures continued to reach record highs at many high-latitude and mountain locations.In the high northern latitudes, the annual surface-air temperature across the Arctic was the fifth highest in the 123-year record. The seasonal Arctic minimum sea-ice extent, typically reached in September, was the 11th-smallest in the 43-year record; however, the amount of multiyear ice—ice that survives at least one summer melt season—remaining in the Arctic continued to decline. Since 2012, the Arctic has been nearly devoid of ice more than four years old.In Antarctica, an unusually large amount of snow and ice fell over the continent in 2022 due to several landfalling atmospheric rivers, which contributed to the highest annual surface mass balance, 15% to 16% above the 1991–2020 normal, since the start of two reanalyses records dating to 1980. It was the second-warmest year on record for all five of the long-term staffed weather stations on the Antarctic Peninsula. In East Antarctica, a heatwave event led to a new all-time record-high temperature of −9.4°C—44°C above the March average—on 18 March at Dome C. This was followed by the collapse of the critically unstable Conger Ice Shelf. More than 100 daily low sea-ice extent and sea-ice area records were set in 2022, including two new all-time annual record lows in net sea-ice extent and area in February.Across the world’s oceans, global mean sea level was record high for the 11th consecutive year, reaching 101.2 mm above the 1993 average when satellite altimetry measurements began, an increase of 3.3±0.7 over 2021. Globally-averaged ocean heat content was also record high in 2022, while the global sea-surface temperature was the sixth highest on record, equal with 2018. Approximately 58% of the ocean surface experienced at least one marine heatwave in 2022. In the Bay of Plenty, New Zealand’s longest continuous marine heatwave was recorded.A total of 85 named tropical storms were observed during the Northern and Southern Hemisphere storm seasons, close to the 1991–2020 average of 87. There were three Category 5 tropical cyclones across the globe—two in the western North Pacific and one in the North Atlantic. This was the fewest Category 5 storms globally since 2017. Globally, the accumulated cyclone energy was the lowest since reliable records began in 1981. Regardless, some storms caused massive damage. In the North Atlantic, Hurricane Fiona became the most intense and most destructive tropical or post-tropical cyclone in Atlantic Canada’s history, while major Hurricane Ian killed more than 100 people and became the third costliest disaster in the United States, causing damage estimated at $113 billion U.S. dollars. In the South Indian Ocean, Tropical Cyclone Batsirai dropped 2044 mm of rain at Commerson Crater in Réunion. The storm also impacted Madagascar, where 121 fatalities were reported.As is typical, some areas around the world were notably dry in 2022 and some were notably wet. In August, record high areas of land across the globe (6.2%) were experiencing extreme drought. Overall, 29% of land experienced moderate or worse categories of drought during the year. The largest drought footprint in the contiguous United States since 2012 (63%) was observed in late October. The record-breaking megadrought of central Chile continued in its 13th consecutive year, and 80-year record-low river levels in northern Argentina and Paraguay disrupted fluvial transport. In China, the Yangtze River reached record-low values. Much of equatorial eastern Africa had five consecutive below-normal rainy seasons by the end of 2022, with some areas receiving record-low precipitation totals for the year. This ongoing 2.5-year drought is the most extensive and persistent drought event in decades, and led to crop failure, millions of livestock deaths, water scarcity, and inflated prices for staple food items.In South Asia, Pakistan received around three times its normal volume of monsoon precipitation in August, with some regions receiving up to eight times their expected monthly totals. Resulting floods affected over 30 million people, caused over 1700 fatalities, led to major crop and property losses, and was recorded as one of the world’s costliest natural disasters of all time. Near Rio de Janeiro, Brazil, Petrópolis received 530 mm in 24 hours on 15 February, about 2.5 times the monthly February average, leading to the worst disaster in the city since 1931 with over 230 fatalities.On 14–15 January, the Hunga Tonga-Hunga Ha'apai submarine volcano in the South Pacific erupted multiple times. The injection of water into the atmosphere was unprecedented in both magnitude—far exceeding any previous values in the 17-year satellite record—and altitude as it penetrated into the mesosphere. The amount of water injected into the stratosphere is estimated to be 146±5 Terragrams, or ∼10% of the total amount in the stratosphere. It may take several years for the water plume to dissipate, and it is currently unknown whether this eruption will have any long-term climate effect